Re: Don't rebind built-in names* - it confuses readers
On 6/10/2013 10:56 PM, Steven D'Aprano wrote: I was initially confused and reading the code still takes a small bit of extra mental energy. Idle stays confused and will wrongly color the list instance name until it is changed. Calling the file list 'fnames' or 'filenames' would have been clearer to both me and Idle. Correct. The downside of editors that colourise text is that sometimes they colourise it wrong. In this case, how is the editor supposed to know that list no longer refers to the built-in list? This is yet another good argument for being cautious about shadowing built-ins. After posting I remembered that there are also colorized text blocks on web pages. Each person will have to decide for themselves whether the convenience of reusing a builtin name is worth having their code mis-colorized. As a reader, I decided that it is not. tjr -- http://mail.python.org/mailman/listinfo/python-list
Re: Newbie: question regarding references and class relationships
On 6/10/2013 12:09 PM, Rui Maciel wrote: We've established that you don't like attribute declarations, at least those you describe as not fulfill a technical purpose. What I don't understand is why you claim that that would cause nothing but trouble. Three answers: Look how much trouble it has already caused ;-) Since you are a self-declared newbie, believe us! Since, be definition, useless code can do no good, it can only cause trouble. Think about it. Terry -- http://mail.python.org/mailman/listinfo/python-list
Re: Newbie: question regarding references and class relationships
On 6/10/2013 9:18 AM, Rui Maciel wrote: class Model: points = [] lines = [] Unless you actually need keep the points and lines ordered by entry order, or expect to keep sorting them by whatever, sets may be better than lists. Testing that a point or line is in the model will be faster, as will deleting one by its identify. -- http://mail.python.org/mailman/listinfo/python-list
Re: py_compile vs. built-in compile, with __future__
On 6/10/2013 11:33 AM, dhyams wrote: The built-in compile() function has a flags parameter that one can use to influence the __future__ mechanism. However, py_compile.compile, which I'm using to byte-compile code, doesn't have an equivalent means to do this. That flag was added to compile bacause it is needed to compile expressions and single statements, whether in string or ast form, that use future syntax. It is impossible to include a future statement with either. It is not needed for compiling multiple statements. Is this by design, or would this be considered a bug? Design, not needed. import __future__ py_compile.compile(foobar.py,flags=__future__.CO_FUTURE_DIVISION) Put the future statement inside foobar.py just as you would do if running it from the command line. Notice that there is no command-line future flag either. Terry -- http://mail.python.org/mailman/listinfo/python-list
Re: Newbie: question regarding references and class relationships
On 6/10/2013 4:13 PM, Rui Maciel wrote: Terry Jan Reedy wrote: Three answers: Look how much trouble it has already caused ;-) Since you are a self-declared newbie, believe us! Since, be definition, useless code can do no good, it can only cause trouble. Think about it. I don't doubt that there might good reasons for that, but it is always preferable to get the rationale behind a decision to be able to understand how things work and how to do things properly. I agree actually. But sometimes is it hard to articulate 'good reasons' for a principle based on the integration of over a decade of experience. I was really trying to point to the difference between 'I will not accept the experience-based advice until enough good reasons are presented.' and 'I will provisionally accept the advice but I would still like to know why.' Another principle similar to 'Don't add extraneous code' is 'Don't rebind builtins*'. I have a separate post for that. Terry -- http://mail.python.org/mailman/listinfo/python-list
Don't rebind built-in names* - it confuses readers
Many long-time posters have advised Don't rebind built-in names*. * Unless you really mean to mask it, or more likely wrap it, such as wrapping print to modify some aspect of its operation than one cannot do with its keyword parameters. The point for this post is that such wrapping modify or extend the basic meaning of the builtin, but do not abolish it. Reasons have been given in various related forms: 'my long experience tells me its bad', 'you may need the builtin later', 'you may forget that you rebound the builtin, 'it can lead to subtle bugs, etc. Leaving aside the code writer and code operation, I recently discovered that it is not nice for readers, whether humans or programs. For instance, open Lib/idlelib/GrepDialog.py in an editor that colorizes Python syntax, such as Idle's editor, jump down to the bottom and read up, and (until it is patched) find list.append(fn) with 'list' colored as a builtin. Stop. That looks wrong. List.append needs two arguments: a list instance and an object to append to the list. The 'solution' is in a previous line list = [] Reading further, one sees that the function works with two lists, a list of file names, unfortunately called 'list', and a list of subdirectories, more sensibly call 'subdirs'. I was initially confused and reading the code still takes a small bit of extra mental energy. Idle stays confused and will wrongly color the list instance name until it is changed. Calling the file list 'fnames' or 'filenames' would have been clearer to both me and Idle. -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Idiomatic Python for incrementing pairs
On 6/8/2013 12:16 AM, Tim Chase wrote:
On 2013-06-08 07:04, Carlos Nepomuceno wrote:
alpha, beta = (1 if some_calculation(params) else 0, 1 if
other_calculation(params) else 0)
This one sets them to absolute values, rather than the incrementing
functionality in question:
alpha += temp_a
beta += temp_b
The actual code in question does the initialization outside a loop:
alphas_updated = betas_updated = 0
for thing in bunch_of_things:
a, b = process(thing)
alphas_updated += a
betas_updated += b
I am pretty sure that this is the faster way to get the result.
and it just bugs me as being a little warty for having temp
variables when Python does things like tuple-unpacking so elegantly.
So use it ;-).
That said, as mentioned in a contemporaneous reply to Jason, I haven't
found anything better that is still readable.
The generalization of what you want is a mutable vector with an in-place
augmented assignment version of element by element addition. That
probably has been written. Nnmpy arrays do vector addition and maybe do
it in-place also (I just do ot know). But here is a custom class for the
problem you presented.
def process(val):
return val, 2*val
class Pair(list):
def __init__(self, a, b):
self.append(a)
self.append(b)
def inc(self, a, b):
self[0] += a
self[1] += b
pair = Pair(0, 0)
for val in [1,2,3]:
pair.inc(*process(val))
print(pair)
[6, 12]
This is cleaner but a bit slower than your in-lined version. I did not
use __iadd__ and += because unpacking 'other' (here the process return)
in the call does the error checking ('exactly two values') for 'free'.
--
Terry Jan Reedy
--
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Re: Mistakes in documentation
On 6/6/2013 8:01 AM, Paul Volkov wrote: Where can I submit little mistakes in Python documantation? I found one while browsing tutorial.pdf (Python 3.3.2): Section 3.1 says (on page 12): word[2:5] # characters from position 2 (included) to 4 (excluded) ’tho’ Shouldn't the comment say 5 (excluded) or 4 (included) instead? At the bottom of the index page, in the Meta information section, is an entry for the Reporting bugs doc. It says to email d...@python.org or to use the tracker for a persistent record. This is followed by an explanation of using the tracker. Terry -- http://mail.python.org/mailman/listinfo/python-list
Re: Bools and explicitness [was Re: PyWart: The problem with print]
On 6/5/2013 2:11 AM, Russ P. wrote: But then, what would you expect of a language that allows you to write x = 1 x = Hello It's all loosey goosey -- which is fine for many applications but certainly not for critical ones. I believe Shedskin, a Python *subset* compiler*, will reject that, because it compiles ints to C ints. Some code checkers might too. -- http://mail.python.org/mailman/listinfo/python-list
Dijkstra (was Re: Source code to identify user through browser?)
On 6/5/2013 6:07 PM, Carlos Nepomuceno wrote: Didn't know he was such a humorist! lol Although I prefer when he's serious: http://www.cs.utexas.edu/~EWD/transcriptions/EWD10xx/EWD1094.html pythonic summary: Let S be an finite iterable of numbers (make it not an iterable if one interprets the conclusion as requiring reiteration) and let n = len(S) (or len(list(S)) if need be). The if n 2 and len(set(S)) 1, n * min(S) sum(S) max(S) # easily shown by induction on n If the n = 1 or the items in S are all the same, n*min == sum == n*max I might call this the 'Averages are not extreme' theorem. Corollary: if min(s) == 1 and sum(S) n, then max(S) 1 'Pigeonhole Principle' -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Interactive interpreter hooks
On 6/3/2013 3:55 AM, Steven D'Aprano wrote: The sys module defines two hooks that are used in the interactive interpreter: * sys.displayhook(value) gets called with the result of evaluating the line when you press ENTER; * sys.excepthook(type, value, traceback) gets called with the details of the exception when your line raises an exception. Is there a way to hook into the interactive interpreter *before* it is evaluated? That is, if I type len([]) at the prompt and hit ENTER, I want a hook that runs before len([]) is evaluated to 0, so that I get the string len([]). You have not said what you are actually trying to do, but you could definitely modify Idle to do something with user input before it sends it to the user process. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python 2-3 compatibility
On 6/2/2013 10:13 AM, Jason Swails wrote: Because Python 2.4 and 2.5 don't support the except Exception as err: syntax, I've used except Exception, err: Is there any way of getting this effect in a way compatible with Py2.4 and 3.x? Don't do either. Just catch the exception with 'except Exception:' and access the details in the body. I googled 'python 2 to 3 exceptions' and the second hit is http://python3porting.com/noconv.html which covers what you are doing ;-). From that page If you need to support Python versions lower than Python 2.6 and you need access to the exception that was raised, you can get that in all versions through the exc_info() function: import sys try: ... a = 1/'0' ... except (ZeroDivisionError, TypeError): ... e = sys.exc_info()[1] ... print(e.args[0]) unsupported operand type(s) for /: 'int' and 'str' There are more tips on that page, a reference to the six module, and more hits on the search page. Good luck. You are not the first to support the same range of versions (and for the same reasons). -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Future standard GUI library
On 6/1/2013 4:46 PM, Chris Angelico wrote: On Sun, Jun 2, 2013 at 4:18 AM, Wolfgang Keller felip...@gmx.net wrote: And by screenworkers I didn't refer to programmers. Those people rarely have to use the stuff that they implement. Of course not, programmers never use software they've themselves written. Never. Not in a million... oh wait, what's this I have? Hmm, gcc used to compile gcc, RosMud being used by Rosuav, Neil Hodgson using SciTE... naw, they're all statistical anomalies, carry on! And I use Idle to improve Idle. I use the HgWorkbench front-end to hg because point and click is often *faster* for me than remember (or look up command and arg) and type (without error, or correction after error). Now back to ignoring the troll. Terry -- http://mail.python.org/mailman/listinfo/python-list
Re: The state of pySerial
On 5/29/2013 4:00 PM, William Ray Wing wrote: On May 29, 2013, at 2:23 PM, Ma Xiaojun damage3...@gmail.com wrote: Hi, all. pySerial is probably the solution for serial port programming. Physical serial port is dead on PC but USB-to-Serial give it a second life. Serial port stuff won't interest end users at all. But it is still used in the EE world and so on. Arduino uses it to upload programs. Sensors may use serial port to communicate with PC. GSM Modem also uses serial port to communicate with PC. Unforunately, pySerial project doesn't seem to have a good state. I find pySerial + Python 3.3 broken on my machine (Python 2.7 is OK) . There are unanswered outstanding bugs, PyPI page has 2.6 while SF homepage still gives 2.5. Any idea? -- http://mail.python.org/mailman/listinfo/python-list Let me add another vote/request for pySerial support. I've been using it with python 2.7 on OS-X, unaware that there wasn't a path forward to python 3.x. If an external sensor absolutely positively has to be readable, then RS-232 is the only way to go. USB interfaces can and do lock up if recovery from a power failure puts power on the external side before the computer has finished initializing the CPU side. RS-232, bless its primitive heart, could care less. Then 'someone' should ask the author his intentions and offer to help or take over. I did some RS-232 interfacing in the 1980s, and once past the fiddly start/stop/parity bit, baud rate, and wiring issues, I had a program run connected to multiple machines for years with no more interface problems. Terry -- http://mail.python.org/mailman/listinfo/python-list
Re: The state of pySerial
On 5/29/2013 3:47 PM, Grant Edwards wrote: On 2013-05-29, Ma Xiaojun damage3...@gmail.com wrote: pySerial is probably the solution for serial port programming. Physical serial port is dead on PC but USB-to-Serial give it a second life. Serial port stuff won't interest end users at all. But it is still used in the EE world and so on. Arduino uses it to upload programs. Sensors may use serial port to communicate with PC. GSM Modem also uses serial port to communicate with PC. Unforunately, pySerial project doesn't seem to have a good state. I find pySerial + Python 3.3 broken on my machine (Python 2.7 is OK) . There are unanswered outstanding bugs, PyPI page has 2.6 while SF homepage still gives 2.5. Any idea? Volunteer as a maintainer and start fixing bugs? It seems to be getting around 200 downloands a day. Quite worth someone supporting it. I use pyserial regularly, and the current version works fine for me, but I'm using Python 2.7. There are still too many libraries that don't support 3.x for me to consider using 3.x for real work. The only download is a .exe. It it just the executable binary or is that a zip unpacker with source? -- http://mail.python.org/mailman/listinfo/python-list
Re: Python #ifdef
On 5/28/2013 6:25 PM, Joel Goldstick wrote: On Tue, May 28, 2013 at 6:18 PM, Mark Lawrence breamore...@yahoo.co.uk mailto:breamore...@yahoo.co.uk wrote: On 28/05/2013 20:46, Carlos Nepomuceno wrote: I'd like to have something like '#ifdef' to mix code from Python 2 and 3 in a single file. https://pypi.python.org/pypi/__six/1.3.0 https://pypi.python.org/pypi/six/1.3.0 my original response was from cell phone. I just answered that you can't do ifdefs, implying that there is no preprocessor in python. I learned a lot of things I didn't know reading the thread, but I wonder if it is a good idea in general to try to write code like this. -- combined 2.x/3.x codebase can be a bear to maintain. Many people have come to prefer a) a single 23 codebase over b) separate 2 and 3 codebases or c) a single 2 codebase repeatedly converted to a 3 codebase with 2to3. They use 2to3 once (well, a few times) to discover differences that need to be considered. For 2.7 and 3.x, the future imports are enough for some code. The six module handles harder cases. I wouldn't do it unless there was some imposing reason that I must. Its not just print() -- that isn't bad, but changes in module names (urllib), I believe six handles that arithmetic, and from __future__ import integer_division # spelling? handles the only change unicode Use unicode consistently and from __future__ import unicode_literals # spelling? or the re-addition u'' prefix do quite well. Otherwise, do not use things that evaporated, like apply() and classic classes. (Inherit from object if nothing else.) This is all hearsay coming from me ;-). Terry -- http://mail.python.org/mailman/listinfo/python-list
Re: Python error codes and messages location
On 5/27/2013 12:54 PM, Carlos Nepomuceno wrote: I think PEP 3151 is a step ahead! That's almost exactly what I was looking for. Why did it take so long to have that implemented? Since this PEP involved changing existing features, rather than adding something mew, it probably took moe time and discussion to get consensus on details of the change. -- http://mail.python.org/mailman/listinfo/python-list
Re: Short-circuit Logic
On 5/26/2013 7:11 AM, Ahmed Abdulshafy wrote: if not allow_zero and abs(x) sys.float_info.epsilon: print(zero is not allowed) The reason for the order is to do the easy calculation first and the harder one only if the first passes. -- http://mail.python.org/mailman/listinfo/python-list
Re: Output from to_bytes
On 5/26/2013 8:02 AM, Mok-Kong Shen wrote: for k in range(8,12,1): print(k.to_bytes(2,byteorder='big')) http://bugs.python.org/issue9951 http://bugs.python.org/issue3532 import binascii as ba for k in range(8,12,1): print(ba.hexlify(k.to_bytes(2,byteorder='big'))) b'0008' b'0009' b'000a' b'000b' -- http://mail.python.org/mailman/listinfo/python-list
Re: Encodign issue in Python 3.3.1 (once again)
On 5/26/2013 12:36 PM, Νίκος Γκρ33κ wrote:
This is the code that although correct becaus it works with englisg(standARD
ASCII letters) it wont with Greek:
if( log ):
name = log
# print specific client header info
cur.execute('''SELECT hits, money FROM clients WHERE name = %s''',
(name,) )
data = cur.fetchone()
===
The following is the live output of: tail -F /usr/local/apache/logs/error_log
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] Error in
sys.excepthook:, referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] UnicodeEncodeError:
'ascii' codec can't encode characters in position 2050-2056: ordinal not in
range(128), referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] , referer:
http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] Original exception
was:, referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] Traceback (most recent
call last):, referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] File pelatologio.py, line
122, in module, referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11]
cur.execute('''SELECT hits, money FROM clients WHERE name = %s''', (name,) ),
referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] File
/opt/python3/lib/python3.3/site-packages/pymysql/cursors.py, line 108, in
execute, referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] query =
query.encode(charset), referer: http://superhost.gr/cgi-bin/pelatologio.py
[Sun May 26 19:24:04 2013] [error] [client 46.12.46.11] UnicodeEncodeError:
'latin-1' codec can't encode characters in position 46-52: ordinal not in
range(256), referer: http://superhost.gr/cgi-bin/pelatologio.py
This appears to be an issue with your mysql database and how you set it
up.. It is using charset='latin-1' whereas you need it to consistently
use charset='utf8' both for storing strings and for retrieval. Check the
mysql manual or ask on a mysql list for how to do that. I have no idea
so don't ask me, or send mail to my emall address.
--
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Re: Cutting a deck of cards
On 5/26/2013 3:54 PM, Carlos Nepomuceno wrote: From: usenetm...@solar-empire.de [...] Not in Python3.x decks = 6 list(range(13 * 4 * decks)) == range(13 * 4 * decks) False Adiaŭ Marc What does list(range(13 * 4 * decks)) returns in Python 3? A list, obviously. What you should ask is what range returns in Python 3, and you should install python 3 and try it, and list its attributes. -- http://mail.python.org/mailman/listinfo/python-list
Re: Short-circuit Logic
On 5/26/2013 4:22 PM, Roy Smith wrote: In article mailman.2196.1369599562.3114.python-l...@python.org, Terry Jan Reedy tjre...@udel.edu wrote: On 5/26/2013 7:11 AM, Ahmed Abdulshafy wrote: if not allow_zero and abs(x) sys.float_info.epsilon: print(zero is not allowed) The reason for the order is to do the easy calculation first and the harder one only if the first passes. This is a particularly egregious case of premature optimization. You're worried about how long it takes to execute abs(x)? That's silly. This is a particularly egregious case of premature response. You're ignoring an extra name lookup and two extra attribute lookups. That's silly. That's beside the fact that one *must* choose, so any difference is a reason to act rather than being frozen like Buridan's ass. http://en.wikipedia.org/wiki/Buridan%27s_ass If you wish, replace 'The reason' with 'A reason'. I also the logical flow as better with the order given. -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple algorithm question - how to reorder a sequence economically
On 5/24/2013 4:14 AM, Peter Brooks wrote: What is the easiest way to reorder a sequence pseudo-randomly? That is, for a sequence 1,2,3,4 to produce an arbitrary ordering (eg 2,1,4,3) that is different each time. I'm writing a simulation and would like to visit all the nodes in a different order at each iteration of the simulation to remove the risk of a fixed order introducing spurious evidence of correlation. random module has a shuffle function I believe -- http://mail.python.org/mailman/listinfo/python-list
Re: Newbie question about evaluating raw_input() responses
On 5/23/2013 12:47 AM, Steven D'Aprano wrote: On Wed, 22 May 2013 22:31:04 +, Alister wrote: Please write out 1000 time (without using any form of loop) NEVER use input in python 3.0 it is EVIL* But all joking aside, eval is dangerous, yes, but it is not evil. He put that label on *input*, not eval -- I presume for hiding dangerous eval. -- http://mail.python.org/mailman/listinfo/python-list
Re: subclassing from unittest
On 5/23/2013 2:58 AM, Ulrich Eckhardt wrote:
Well, per PEP 8, classes use CamelCaps, so your naming might break
automatic test discovery. Then, there might be another thing that could
cause this, and that is that if you have an intermediate class derived
from unittest.TestCase, that class on its own will be considered as test
case! If this is not what you want but you still want common
functionality in a baseclass, create a mixin and then derive from both
the mixin and unittest.TestCase for the actual test cases.
This is now standard practice, gradually being implemented everywhere in
the CPython test suite, for testing C and Py versions of a module.
class TestXyz():
mod = None
test_a, etc, methods
class TestXyz_C(TestXyz, TextCase): # Test C version
mod = support.import_fresh_module('_xyz') # approximately right
class TestXyz_Py(TestXyz, TextCase): # Test Python version
mod = support.import_fresh('xyz')
This minimizes duplication and ensures that both implementations get
exactly the same tests.
tjr
--
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Re: how to get the socket module compiled with SSL support
On 5/23/2013 9:58 AM, Kihup Boo wrote: I am trying to make an HTTPS connection and read that HTTPS support is only available if the socket module was compiled with SSL support. _http://www.jython.org/docs/library/httplib.html_ Can someone elaborate on this? Where can I get the socket module for HTTPS, or how do I build one if I have to? This is mostly a CPython oriented list. Any prebuilt CPython binary you get likely has SSL support compiled in. If you want to know about the jython socket module, you should check on a jython list, or just try it. -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 378: Format Specifier for Thousands Separator
On 5/23/2013 2:42 PM, Dave Angel wrote: On 05/23/2013 11:26 AM, Carlos Nepomuceno wrote: eggs(a,f) Traceback (most recent call last): File pyshell#29, line 1, in module eggs(a,f) File pyshell#1, line 1, in eggs def eggs(spam, ham): return spam % ham TypeError: not all arguments converted during string formatting '%s'%(5%3) '2' So % doesn't handle tuples! Why's that? Is it intentional (by design)? It's a conflict in the design. A tuple is used to supply multiple arguments to the % operator. So if you want to have a tuple as the first argument, you need to enclose it in another tuple. The problem is that interpolating 1 to many items into a string is *not* a binary operation. The needed hack to pretend that it is, using a tuple to represent multiple items rather than just itself, was one of the reasons for making string formatting a honest function, where multiple items to be formatted are passed as multiple arguments. -- http://mail.python.org/mailman/listinfo/python-list
Re: Non-identifiers in dictionary keys for **expression syntax
On 5/23/2013 2:52 PM, Matthew Gilson wrote:
This is a question regarding the documentation around dictionary
unpacking. The documentation for the call syntax
(http://docs.python.org/3/reference/expressions.html#grammar-token-call)
says:
If the syntax **expression appears in the function call, expression
must evaluate to a mapping, the contents of which are treated as
additional keyword arguments.
That's fine, but what is a keyword argument? According to the glossary
(http://docs.python.org/3.3/glossary.html):
/keyword argument/: an argument preceded by an identifier (e.g. name=)
in a function call or passed as a value in a dictionary preceded by **.
It appears that the requirement has been relaxed (in the previous
quote), so that 'dictionary' should also be changed to 'mapping'. It
might not hurt to add 'The key for the value should be an identifier.'
As far as I'm concerned, this leads to some ambiguity in whether the
keys of the mapping need to be valid identifiers or not.
I think you are being too lawyerly. The pretty clear and sensible
implication is that the key for the value should be a string with a
valid identifier. If it is anything else, you are on your own and
deserve any joy or pain that results ;=)
Using Cpython, we can do the following:
def func(**kwargs):
print kwargs
d = {'foo bar baz':3}
So that might lead us to believe that the keys of the mapping do not
need to be valid identifiers.
There are two ways to pass args to func to be gathered into kwargs;
explicit key=val pairs and **mapping, or both.
func(a=1, b='hi', **{'foo bar baz':3})
#
{'foo bar baz': 3, 'a': 1, 'b': 'hi'}
So func should not expect anything other than identifier strings.
However, the previous function does not
work with the following dictionary:
d = {1:3}
because not all the keys are strings.
So CPython checks that keys are strings, because that is cheap, but not
that the strings are identifiers, because that would be more expensive.
Just because an implementation allow somethings (omits a check) for
efficiency does not mean you should do it.
globals()[1] = 1
works, but is not normally very sensible or useful.
Is there a way to petition to get this more rigorously defined?
bugs.python.org
The problem is that mandating a rigorous check by implementations makes
Python slower to the detriment of sensible programmers.
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Re: Myth Busters: % this old style of formatting will eventually be removed from the language
On 5/22/2013 10:24 AM, Denis McMahon wrote: Indeed, removing %-formatting could break a substantial amount of live code, with potentially significant maintenance effort in the user While I would like to see % formatting go away everntually*, other developers would not. In any case, I agree that it should not disappear until there is a foolproof conversion tool, probably custom written. I am working on other things. * perhaps in 10 years?, when all 2.x code that is going to be converted has been converted -- http://mail.python.org/mailman/listinfo/python-list
Re: What was the project that made you feel skilled in Python?
On 5/22/2013 9:05 AM, Ben Finney wrote: I wanted to simulate a particular board game, and had others in mind with some common mechanics. This resulted in a library for rolling dice in different combinations, and looking up result tables URL:https://pypi.python.org/pypi/alea. Have you cosidered adding a description so it can be found be a search? A 3.3 version? Simulate game randomizers and lookup: dice rolls, card drawing, spinners, ... Eventually I wanted to extend it to know about custom decks of cards, and the different ways those are handled in board games. The unifying theme was a library of routines for simulating the random elements (dice, cards, tables, spinners, etc.) in any board game. A little over-engineered, I'll freely admit. But it did give me a sense of being at home in Python and knowing that this is a good language for getting things done the right way. -- http://mail.python.org/mailman/listinfo/python-list
Re: subclassing from unittest
On 5/22/2013 11:32 AM, Charles Smith wrote: Have you red this? I will suggest some specifics. http://www.catb.org/esr/faqs/smart-questions.html I'd like to subclass from unittest.TestCase. What version of Python. I observed something interesting and wonder if anyone can explain what's going on... some subclasses create null tests. I can create this subclass and the test works: What does 'works' mean? class StdTestCase (unittest.TestCase): blahblah I bet that this (and the rest of your 'code' is not what you actually ran. Unless blahblah is bound (to what?), this fails with NameError. Give us what you ran so we can run it too, and modify it. and I can create this subsubclass and the test works: class aaaTestCase (StdTestCase): moreblahblah but if I create this subsubclass (or any where the first letter is capital): class AaaTestCase (StdTestCase): differentblahblah the test completes immediately without any work being done. What does this mean? I see no difference with the following import unittest class StdTestCase (unittest.TestCase): pass class lowerSub(StdTestCase): pass class UpperSub(StdTestCase): pass unittest.main(verbosity=2, exit=False) # prints (3.3) -- Ran 0 tests in 0.000s OK Same as before the subclasses were added. -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Future standard GUI library
On 5/20/2013 1:04 AM, Vito De Tullio wrote: Terry Jan Reedy wrote: Do you think tkinter is going to be the standard python built-in gui solution as long as python exists? AT the moment, there is nothing really comparable that is a realistic candidate to replace tkinter. FLTK? (http://www.fltk.org/index.php) tkinter is the Python wrapper of the tk library, just as wxpython is the python wrapper of the wx library. I do not see a py-fltk wrapper. -- http://mail.python.org/mailman/listinfo/python-list
Re: What was the project that made you feel skilled in Python?
On 5/20/2013 3:36 PM, Thomas Murphy wrote: talking about patches in the stdlib? Is there a separate library of patches? http://bugs.python.org http://docs.python.org/devguide/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Harmonic distortion of a input signal
On 5/19/2013 6:49 PM, Oscar Benjamin wrote: import numpy as np Create a square wave signal: x = np.zeros(50) x[:25] = -1 x[25:] = +1 x array([-1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., -1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1.]) Compute the magnitude spectrum: spect = abs(np.fft.fft(x)[:25]) spect array([ 0., 31.85194222, 0., 10.67342282, 0., 6.47213595, 0., 4.69726931, 0., 3.73254943, 0., 3.13762901, 0., 2.7436023 , 0., 2.47213595, 0., 2.28230601, 0., 2.15105461, 0., 2.06487174, 0., 2.01589594, 0.]) Find the index of the maximum element: np.argmax(spect) 1 So the peak is the lowest non-zero frequency component of the DFT. In Hz this corresponds to a frequency of 1/T where T is the duration of the signal. While you were answering a specific question, I think the above is a nice tutorial example, because it is more meaningful than arbitrary operations applied to random data. -- http://mail.python.org/mailman/listinfo/python-list
Re: python script is not running
On 5/18/2013 6:12 AM, Avnesh Shakya wrote:
hi,
i want to run python script which generating data into json fromat, I am
using crontab, but it's not executing...
my python code--
try.py --
import json
import simplejson as json
import sys
def tryJson():
saved = sys.stdout
correctFile = file('data.json', 'a+')
sys.stdout = correctFile
Don't need to change stdout.
result = []
i = 1
for i in range(5):
info = {
'a': i+1,
'b': i+2,
'c': i+3,
}
result.append(info)
What is you want to add print result for debugging?
if result:
print json.dumps(result, indent=6)
Either use print correctFile, correctFile.write (do you really want
the extra '\n' that print adds?), or, do the future import of print as
function and pass correctFile as the file argument
sys.stdout = saved
correctFile.close()
tryJson()
--
http://mail.python.org/mailman/listinfo/python-list
Re: how to run another file inside current file?
On 5/18/2013 7:15 AM, Kevin Xi wrote:
Hi,
It's better to specify version of python you work with.
Absolutely.
I know nothing
about python 3 but in python 2 you can do this with `exec`. Example:
f = file('otherFile.py')
exec f
Py 2 has execfile that does the above. Py 3 do as above except that exec
is a function.
with open('otherfile.py') as f:
exex(f)
For more, read the doc:
http://docs.python.org/2.7/reference/simple_stmts.html#the-exec-statement
HTH
--
http://mail.python.org/mailman/listinfo/python-list
Re: Future standard GUI library
On 5/18/2013 10:03 AM, Beinan Li wrote: Not sure if this is the right place to talk about this. It is. Even less sure if I can move this discussion to tkinter list, The idea of replacing tkinter is not about improving tkinter ;-). Do you think tkinter is going to be the standard python built-in gui solution as long as python exists? AT the moment, there is nothing really comparable that is a realistic candidate to replace tkinter. Tkinter is a tcl-based c gui library. wx and qt4 are gui application frameworks that include a gui library -- and much more that duplicate part of Python's stdlib. They, and consequently their Python wrappers, are too big. That is quite aside from the fact that the authors of the wrappers have good reason to not donate their code, but stay independent. PyGui was designed as a gui library comparable to tkinter and a possible replacement. But according to the web page, it is still not completely ready for py 3 (the last update was July 2011). http://www.cosc.canterbury.ac.nz/greg.ewing/python_gui/ I think a tkinter replacement should be written for at least 3.4+, so it can use the new 3.3 unicode implementation and use or at least integrate with the new 3.4 event loop that will be part of the planned new async library. One test for any new gui library is whether idle can be rewritten in it. It heavily uses the tag features of the tk text widget. TJR -- http://mail.python.org/mailman/listinfo/python-list
Re: TypeError: unbound method add() must be called with BinaryTree instance as first argument (got nothing instead)
On 5/18/2013 3:46 PM, Peter Otten wrote: Dan Stromberg wrote: python 2.x, python 3.x and pypy all give this same error, though jython errors out at a different point in the same method. By the way, 3.x doesn't have unbound methods, so that should work. It does for this example (3.3.1) c = C() c.m() __main__.C object at 0x033FC5F8 C.m(c) __main__.C object at 0x033FC5F8 C.m(self=c) __main__.C object at 0x033FC5F8 -- http://mail.python.org/mailman/listinfo/python-list
Re: Python for philosophers
On 5/15/2013 9:17 PM, Tim Daneliuk wrote: http://pvspade.com/Sartre/cookbook.html Wikedly funny. -- http://mail.python.org/mailman/listinfo/python-list
Re: Fwd: Python for philosophers
2013/5/14 Steven D'Aprano steve+comp.lang.pyt...@pearwood.info mailto:steve+comp.lang.pyt...@pearwood.info Python is not named after the snake, but after Monty Python the British comedy troupe. And they picked their name because it sounded funny. That does not mean they were unaware that Pythons are snakes. requiring a slippery-sounding surname, they settled on Python http://en.wikipedia.org/wiki/Monty_Python http://en.wikipedia.org/wiki/Monty_Python -- http://mail.python.org/mailman/listinfo/python-list
Re: Writing a blog post on the new Enum.
On 5/14/2013 3:52 AM, Chris Angelico wrote: On Tue, May 14, 2013 at 9:40 AM, Fábio Santos fabiosantos...@gmail.com wrote: http://fabiosantoscode.blogspot.pt/2013/05/pythons-new-enum-class.html class Text(unicode, Enum): one = u'one' two = u'two' three = u'three' Is this supposed to be a quote? or your rewrite? or did Santos rewrite after you posted? The blog currently has a 3.x version of that. That looks like Python 2 code. Are you backporting Enum to Py2 manually? AIUI the Python core won't be adding features like that to 2.7, and there won't be a 2.8, so PEP 435 will be Py3.4+ only. Or have I misunderstood it? As far as official CPython goes, Enum is 3.4+ only. I believe the module will continue to work on earlier 3.x and will remain externally available as a 3rd party module. Ethan said he plans to backport to 2.7 so 2 3 code can use enums. -- http://mail.python.org/mailman/listinfo/python-list
Re: Old version docs don't link to current version
On 5/12/2013 10:12 AM, Chris Angelico wrote: Not sure if this is an oversight or something deliberate... could be either. From http://docs.python.org/3.0/library/http.server.html there's no link to the current docs, even though from http://docs.python.org/3/library/http.server.html it's possible to switch to 3.2 and then back to 3.3 (or to 2.7, but that fails and redirects since http.server doesn't exist in 2.7). This wouldn't be much of a bother, except that a Google search for 'python http.server' (which is the way I normally pull up Python docs) landed me on /3.0/ instead of /3/. Was this intentional, along the lines of not touching the old and unsupported docs? Cross referencing was added while 3.2 docs were still subject to revision. x.y docs are essentially frozen once the final x.y.z bugfix comes out. Since I always enter the docs through docs.python.org/3/ (or /2/) typing just 'd' on Firefox history bar brings up both on the short history list to select. I then use module or general index. -- http://mail.python.org/mailman/listinfo/python-list
Re: object.enable() anti-pattern
On 5/12/2013 1:14 PM, Wayne Werner wrote: On Fri, 10 May 2013, Gregory Ewing wrote: Wayne Werner wrote: You don't ever want a class that has functions that need to be called in a certain order to *not* crash. That seems like an overly broad statement. What do you think the following should do? f = open(myfile.dat) f.close() data = f.read() To clarify - you don't want a class that has functions that need to be called in a certain order with *valid input* in order to not crash. Exactly what does happen - a ValueError is raised because you're(*) passing self into the file.read() function, and that input is invalid input - specifically: ValueError: I/O operation on closed file *where you actually means python, because when you call `your_instance.method()`, it works effectively like a call to `YourClass.method(your_instance)` The new idiom with open(myfile.dat) as f: data = f.read() partially encapsulates operations on the opened file before the automatic close. It is true however, that after the with statement, f in still uselessly bound to the closed file. (Well, you can check the mode, encoding, and other attributes, so not totally useless.) To completely encapsulate, one can end the block with 'del f'. I checked and this works. Since the external 'as x' name binding is optional, an internal reference to the context manager (the io.xxx instance) is kept in order to call the __exit__ method, and that is not affected by deleting the optional visible binding. tjr -- http://mail.python.org/mailman/listinfo/python-list
Re: object.enable() anti-pattern
On 5/12/2013 12:48 PM, Wayne Werner wrote: I'll share the anti-pattern that I've seen many times (not actually in Python) class CoolPresenter: def __init__(self): self.view = None self.some_property = None self.other_property = None def initialize(self): self.view.disable() data = self.load_data() self.view.data = data self.view.enable() def reload(self): if self.view is None: raise NotInitializedError(Error: Please setup class) self.view.disable() data = self.load_data() self.view.data = data self.view.enable() Then you would see code like this: presenter = CoolPresenter() presenter.view = CoolView() This is just plain silly for a few reasons: - It's ambiguous. I don't know what's required for the CoolPresenter to function properly. - The temporal coupling mentioned earlier. I can create an instance of a class and then call a function (say `reload`) and then boom! My program crashes. There is *no possible* use case of this class where you can use it without a view. Thank you for this examples. It makes Steven's point clearer than the 'file object' example. The problem with the latter is that objectors could could point to file path objects, which are used to do some manipulations of files and directory entries on the storage device *without looking at the specific file data*. Such file data, as opposed to directory data, never enters the program data space and with smart enough devices, need not enter the CPU and its RAM. They could then confuse them with file access objects which are used to transfer specific data *between* files and program data space. The confusion is adied by the fact that file path objects are used to create file access objects. They do separate jobs and it seems that they are well kept separate, even if there are languages where file path objects can have file access functions turned on and off. The motivation behind this anti-pattern that I've seen is the desire to not have a constructor that does too much. So you end out with an empty constructor and temporal coupling, and a terrible API that doesn't clearly explain the requirements of the class. Your class constructor should *require* everything that is necessary to have a stable state when the class is created (i.e. you should be able to properly call any function, set any property without an exception happening) Why? Less bugs, easier to comprehend, change/update your code. Easier to use the class. -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Message passing syntax for objects | OOPv2
On 5/12/2013 1:18 PM, Ned Batchelder wrote: On 5/8/2013 10:39 PM, Mark Janssen wrote: ...The field needs re-invented and re-centered.[...] For anyone who want to be involved. See the wikiwikiweb -- a tool that every programmer should know and use -- and these pages: ComputerScienceVersionTwo and ObjectOrientedRefactored. I've never understood why people use that site: the pages end up being unintelligible cocktail-party noise-scapes with no hope of understanding who is saying what, or in response to whom. I certainly found it confusing that something responder and OP comments were in normal text and italic respectively, and sometimes the opposite, and maybe sometimes both in normal types. -- http://mail.python.org/mailman/listinfo/python-list
Re: object.enable() anti-pattern
On 5/9/2013 1:23 AM, Steven D'Aprano wrote: Besides, this is not to denigrate the idea of a read() function that takes a filename and returns its contents. But that is not an object constructor. It may construct a file object internally, but it doesn't return the file object, so it is completely unrelated to the scenario I described. At least a few stdlib modules that define classes *also* have such functions. They create an instance of the class, call one or more methods, and return the result of the method, discarding the instance. For instance, see the subprocess module, its POpen class, and module functions; or the timeit module, its Timer class, and functions. -- http://mail.python.org/mailman/listinfo/python-list
Re: Forming a small python programming group
On 5/9/2013 2:59 AM, kreta06 wrote: Hi All, I'm looking for one or two medium-advanced python programmers to practice programming on a Windows 7 platform. In addition, any interests in writing python code to query Microsoft SQL databases (2005-2008) is also welcomed. I've coded in python 2.7 and currently am trying to make the switch to 3.2 as there seem to be some changes to the syntax. Start with 3.3 unless you *must* use 3.2. There is one less syntax change and a better unicode string implementation. -- http://mail.python.org/mailman/listinfo/python-list
Re: cello library
On 5/8/2013 6:01 AM, Chris Angelico wrote:
On Wed, May 8, 2013 at 7:39 PM, Mark Lawrence breamore...@yahoo.co.uk wrote:
Hi folks,
I thought some of you might find this interesting [link redacted]
Unredacted: http://libcello.org/
If this is a legit post, can you please elaborate on just _why_ we
would find it interesting? I'm leery of clicking random links like
that without at least some indication. It could be some cool Python
library, or it could be something relating to music, or it could be a
malicious site ready to compromise my browser and your Yahoo account
was compromised to send spam.
Legitimate request, like some I have made of others. Since I trust Mark:
Cello is a GNU99 C library which brings higher level programming to C.
Interfaces allow for structured design
Duck Typing allows for generic functions
Exceptions control error handling
Constructors/Destructors aid memory management
Syntactic Sugar increases readability
C Library means excellent performance and integration
...Cello is licensed under BSD3.
Partly inspired by Python, including this:
/* with automatically closes file at end of scope. */
with (file in open($(File, NULL), prices.bin, wb))) {
...
}
An interesting question is whether it could be used to convert or
rewrite Python to C.
__
Terry Jan Reedy
--
http://mail.python.org/mailman/listinfo/python-list
Re: Why do Perl programmers make more money than Python programmers
On 5/7/2013 9:22 AM, jmfauth road forth on his dead hobbyhorse to hijack yet another thread: # Py 3.3 ascii and non ascii chars timeit.repeat(a = 'hundred'; 'x' in a) [0.11426985953005442, 0.10040049292649655, 0.09920834808588097] timeit.repeat(a = 'maçãé€ẞ'; 'é' in a) [0.2345595188256766, 0.21637172864154763, 0.2179096624382737] Python 3.3 is a language. Languages do not have timings. CPython 3.3.0 is an implementation compiled and run under a particular OS and hardware. With respect to Unicode timings, especially for find/replace, it is obsolete. On my Win7 machine with fresh debug builds from the current repository, I see these times. Python 3.3.1+ (default, May 7 2013, 14:03:12) [MSC v.1600 32 bit (Int from timeit import repeat repeat(a = 'hundred'; 'x' in a) [0.19007337649622968, 0.190116721780754, 0.1900149679567562] repeat(a = 'maçaé??'; 'é' in a) [0.20568874581187716, 0.20568782357178053, 0.20577051776710914] Python 3.4.0a0 (default:32067784f198, May 7 2013, 13:59:10) [MSC v.1600 from timeit import repeat repeat(a = 'hundred'; 'x' in a) [0.1708080882915779, 0.17062978853956826, 0.1706740560642051] repeat(a = 'maçaé??'; 'é' in a) [0.17612111348809734, 0.17562925210324565, 0.17549245315558437] Note 1: debug builds are slower than install builds, especially for microbenchmarks with trivial statements. My installed 3.3.1 on a different machine has timings of about .1 for the ascii test. It is slower for the non-ascii test because the latest improvements were made after 3.3.1 was released. Note 2: 3.4 has additional improvements that speed up everything, so that the 3.4 non-ascii time is faster that even the 3.3 ascii time. Terry -- http://mail.python.org/mailman/listinfo/python-list
Re: Get filename using filefialog.askfilename
On 5/7/2013 4:27 PM, cheirasa...@gmail.com wrote:
file = filedialog.askopenfile ( mode... )
askopenfile is a convenience function that creates an Open dialog
object, shows it, gets the name returned by the dialog, opens the file
with that name, and returns an appropriate normal file object
to open a file with an open dialog box, OK. Made it.
How i get the name of the opened file?
file.name, (at least in 3.3), which in your example below is file.doc
print(file)
the output is: ..name=file.doc...mode=..encoding..
This is the standard string representation of a file object. It is
created from the various attributes of the file instance, including
file.name.
How can i get the second member of 'file'?
Strings do not have fields. The second 'member', would be the second
character, file[1], which is not what you want.
And i am unable to find a detailed reference to this object in the i.net
Use the Fine Manual. The entry for builtin open() function, which you
should read to understand the 'open' part of askopenfile, directs you to
the Glossary entry 'file object' which says There are actually three
categories of file objects: raw binary files, buffered binary files and
text files. Their interfaces are defined in the io module. The canonical
way to create a file object is by using the open() function. The kind
of file object you get is determined by the mode ('b' present or not),
buffer arg, and maybe something else. You can look in the io chapter or
use dir() and help() as John G. suggested.
Python programmers should really learn to use dir(), help(), and the
manuls, including the index and module index.
--
Terry Jan Reedy
--
http://mail.python.org/mailman/listinfo/python-list
Re: Making safe file names
On 5/7/2013 3:58 PM, Andrew Berg wrote: Currently, I keep Last.fm artist data caches to avoid unnecessary API calls and have been naming the files using the artist name. However, artist names can have characters that are not allowed in file names for most file systems (e.g., C/A/T has forward slashes). Are there any recommended strategies for naming such files while avoiding conflicts (I wouldn't want to run into problems for an artist named C-A-T or CAT, for example)? I'd like to make the files easily identifiable, and there really are no limits on what characters can be in an artist name. Sounds like you want something like the html escape or urlencode functions, which serve the same purpose of encoding special chars. Rather than invent a new tranformation, you could use the same scheme used for html entities. (Sorry, I forget the details.) It is possible that one of the functions would work for you as is, or with little modification. Terry -- http://mail.python.org/mailman/listinfo/python-list
Re: First python program, syntax error in while loop
On 5/6/2013 11:31 AM, Roy Smith wrote:
In article mailman.1361.1367847484.3114.python-l...@python.org,
Chris Angelico ros...@gmail.com wrote:
On Mon, May 6, 2013 at 11:08 PM, Roy Smith r...@panix.com wrote:
On the other hand, I've long since given up trying to remember operator
precedence in various languages. If I ever have even the slightest
doubt, I just go ahead and put in the extra parens.
If I ever have even the slightest doubt, I just go ahead and type
language operator precedence into a web search and check it :)
Well, that solves the problem once, and it solves it for me. I figure
if I'm not 100% sure, then maybe other people aren't 100% sure either,
and my adding the extra parens helps them too.
If you keep the Python docs handy, on or off line, the Language manual
Expressions chapter ends with this single page (but better formatted as
a table than here). But I sometimes add parens for quickness or readability.
6.15. Operator precedence
The following table summarizes the operator precedences in Python, from
lowest precedence (least binding) to highest precedence (most binding).
Operators in the same box have the same precedence. Unless the syntax is
explicitly given, operators are binary. Operators in the same box group
left to right (except for comparisons, including tests, which all have
the same precedence and chain from left to right — see section
Comparisons — and exponentiation, which groups from right to left).
Operator Description
lambda Lambda expression
if – else Conditional expression
or Boolean OR
and Boolean AND
not x Boolean NOT
in, not in, is, is not, , =, , =, !=, == Comparisons, including
membership tests and identity tests,
| Bitwise OR
^ Bitwise XOR
Bitwise AND
, Shifts
+, - Addition and subtraction
*, /, //, % Multiplication, division, remainder [5]
+x, -x, ~x Positive, negative, bitwise NOT
** Exponentiation [6]
x[index], x[index:index], x(arguments...), x.attribute Subscription,
slicing, call, attribute reference
(expressions...), [expressions...], {key: value...}, {expressions...}
Binding or tuple display, list display, dictionary display, set display
Footnotes
[1] While abs(x%y) abs(y) is true mathematically, for floats it may
not be true numerically due to roundoff. For example, and assuming a
platform on which a Python float is an IEEE 754 double-precision number,
in order that -1e-100 % 1e100 have the same sign as 1e100, the computed
result is -1e-100 + 1e100, which is numerically exactly equal to 1e100.
The function math.fmod() returns a result whose sign matches the sign of
the first argument instead, and so returns -1e-100 in this case. Which
approach is more appropriate depends on the application.
[2] If x is very close to an exact integer multiple of y, it’s possible
for x//y to be one larger than (x-x%y)//y due to rounding. In such
cases, Python returns the latter result, in order to preserve that
divmod(x,y)[0] * y + x % y be very close to x.
[3] While comparisons between strings make sense at the byte level, they
may be counter-intuitive to users. For example, the strings \u00C7 and
\u0327\u0043 compare differently, even though they both represent the
same unicode character (LATIN CAPITAL LETTER C WITH CEDILLA). To compare
strings in a human recognizable way, compare using unicodedata.normalize().
[4] Due to automatic garbage-collection, free lists, and the dynamic
nature of descriptors, you may notice seemingly unusual behaviour in
certain uses of the is operator, like those involving comparisons
between instance methods, or constants. Check their documentation for
more info.
[5] The % operator is also used for string formatting; the same
precedence applies.
[6] The power operator ** binds less tightly than an arithmetic or
bitwise unary operator on its right, that is, 2**-1 is 0.5.
--
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Re: (Learner-here) Lists + Functions = headache
On 5/5/2013 8:59 PM, Bradley Wright wrote: Hey guys and gals doing this tutorial(codecademy) and needed a bit help from the experienced. I'm writing a function that takes a list(one they supply during runtime) here's what my function is supposed to do Do they supply an example so you can test both your comprehension and code? I think most specs given in natural language need such. 1. for each instance of the string fizz make a count 2. Finally return that count Did you create an example problem to test your code? If not, do so. Did you run your function with example data? If not, do so. here's my code: def fizz_cout(x): count = 0 for item in x: while item == fizz: count += 1 return count Here is hint as to some of what needs to be improved: this function will return either 1 or None. You should have discovered that by testings. -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: to a human - about 2to3
On 5/1/2013 10:52 AM, Jennifer Butler wrote: I will start teaching Python to my pupils shortly. I have been looking for materials and have gathered a collection of programs. The problem is they are written in v2 and I have v3 installed in my classroom. I read about the 2to3 conversion program, but I can’t get it to work. You might find this page http://www.python.org/community/sigs/current/edu-sig/ and the education list itself. I am sure many programs useful in education have already been ported. Many simple programs, of the sort used in beginner classes need minimal change. Oftem 'print x' to 'print(x)' is all that is needed. 2to3 will do that for you, once you learn how to use it, but I have not. For the programs people post on the list, with just 1 or 2 prints, I make the change manually in the Idle editor before running. I often want to change other things as well, so no big deal. -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I encode and decode this data to write to a file?
On 4/29/2013 5:47 AM, c...@isbd.net wrote:
case). Here's the traceback:-
File /usr/local/lib/python2.7/dist-packages/gallery/picture.py, line 361,
in createPictureHTML file.write(.join(html).encode('utf-8'))
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position
783: ordinal not in range(128)
Generiric advice for anyone getting unicode errors:
unpack the composition producing the error
so that one can see which operation produced it.
In this case
s = .join(html)\
s = s.encode('utf-8')
file.write(s)
This also makes it possible to print intermediate results.
print(type(s), s) # would have been useful
Doing so would have immediately shown that in this case the error was
the encode operation, because s was already bytes.
For many other posts, the error with the same type of message has been
the print or write operation, do to output encoding issues, but that was
not the case here.
--
http://mail.python.org/mailman/listinfo/python-list
Re: python.exe has stopped working when os.execl() runs on Windows 7
On 4/27/2013 11:42 PM, cormog...@gmail.com wrote: Is there the place to open a ticket for Python developers? bugs.python.org -- http://mail.python.org/mailman/listinfo/python-list
Re: Comparison Style
On 4/27/2013 5:03 PM, Roy Smith wrote: In article mailman.1077.1366944517.3114.python-l...@python.org, Chris Angelico ros...@gmail.com wrote: If you switch the order of operands in that, the compiler won't help you. Plus it reads wrong. So the convention is still variable==constant. I just found a nice example of putting the constant first. I've just done a whole bunch of ugly math to find some slice limits. To make sure they're sane, I'm writing: assert 5 = i j original_song_count I can't think of any way to write that which would be as clean and easy to read. Chained comparisons like this are standard math notation, which is why Python 'does the right thing' with them. -- http://mail.python.org/mailman/listinfo/python-list
Re: Nested For loop not running full
On 4/26/2013 4:48 AM, inshu chauhan wrote: Hello everyone, I have this part of my code where I am trying to traverse over an image by running a for loop for both x and y co-ordinate axis. But the loop is terminating by just reading first pixel. Can think of a reason why this is happening ? *A* reason could be that segimage.height and .width are both 1. I would print them out to see what they are. The code is: for sy in xrange(0, segimage.height): for sx in xrange(0, segimage.width): if segimage[sy,sx] == (0.0, 0.0, 0.0): continue else: seg_color = segimage[sy,sx] blue = int(seg_color[0]) green = int(seg_color[1]) red = int(seg_color[2]) reg_num = blue + 256 * green + 65536 * red for l in f: sp = l.split(,) if len(sp) == 14: print sy, sx # for checking which pixel its reading currently print reg_num, sp[0] # for checking whats happening if reg_num == int(sp[0].strip()): print reg_num, sp[0].strip() # for checking whats happening classification = int(sp[13].strip()) The inside for loop is for reading a csv format file from which I am extracting some information. Thanks in Advance for your suggestions -- http://mail.python.org/mailman/listinfo/python-list
Re: Libroffice PMT equivalent in python
On 4/25/2013 6:46 AM, ஆமாச்சு wrote: Hi, Are there equivalent in any Python libraries that could match function like PMT in libreoffice? Refer: https://help.libreoffice.org/Calc/Financial_Functions_Part_Two#PMT try the packages listed at https://pypi.python.org/pypi?%3Aaction=searchterm=financesubmit=search -- http://mail.python.org/mailman/listinfo/python-list
Re: My gui
On 4/24/2013 1:53 PM, Chris “Kwpolska” Warrick wrote: Please try fixing it and running it _outside of IDLE_, which is also built in Tk The default mode of Idle runs user code in a separate process. Editing tkinter code with Idle and running it (in the separate process) should be no problem. -- http://mail.python.org/mailman/listinfo/python-list
Re: List Count
On 4/23/2013 7:45 AM, Blind Anagram wrote: I then wondered why count for lists has no limits Probably because no one has asked for such, as least partly because it is not really needed. In any case, .count(s) is a generic method. It is part of the definition of a Sequence. It can also be implemented for non-sequence collections, such as a Tree class, that allow multiple occurrences of an item. whereas count for other objects (e.g. strings) has these. Strings (of unicode or bytes) are exceptional in multiple ways. -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: List Count
On 4/23/2013 12:57 PM, Blind Anagram wrote: So, all I was doing in asking for advice was to check whether there is an easy way of avoiding the slice copy, And there is. not because this is critical, but rather because it is a pity to limit the performance because Python forces a (strictly unnecessary) copy in order to perform a count within a part of a list. Python does not force that. You have been given several simple no-copy alternatives. They happen to be slower *with CPython* because of the speed difference between Python code and C code. If the same timing tests were done with any of the implementations that execute python code faster, the results would likely be different. I thing str/byte/bytearray.count have more need for optional start,stop boundary parameters because a) people search in long texts and subtexts, more so I think that for other sequences, b) they search for substrings longer than 1 and hence c) the generic no-slice alternatives do not work for counting substrings. That said, I do see that tuple/list.index have had start, stop paramaters added, so doing the same for .count is conceivable. I just do not remember anyone else asking for such. The use case must be very rare. And as I said in my other post, .count(x) applies to any collections, but start,stop would only apply to sequences. In other words, the lack of a list.count(value, limit) function makes Python less effective than it would otherwise be. Untrue. The alternatives are just as *effective*. -- http://mail.python.org/mailman/listinfo/python-list
Re: Nested iteration?
On 4/23/2013 11:40 AM, Roy Smith wrote: In reviewing somebody else's code today, I found the following construct (eliding some details): f = open(filename) for line in f: if re.search(pattern1, line): outer_line = f.next() for inner_line in f: if re.search(pattern2, inner_line): inner_line = f.next() Did you possibly elide a 'break' after the inner_line assignment? Somewhat to my surprise, the code worked. Without a break, the inner loop will continue iterating through the rest of the file (billions of lines?) looking for pattern2 and re-binding inner-line if there is another line or raising StopIteration if there is not. Does this really constitute 'working'? This is quite aside from issue of what one wants if there is no pattern1 or if there is no line after the first match (probably not StopIteration) or if there is no pattern2. I didn't know it was legal to do nested iterations over the same iterable Yes, but the effect is quite different for iterators (start where the outer iteration left off) and non-iterators (restart at the beginning). r = range(2) for i in r: for j in r: print(i,j) # this is a common idiom to get all pairs 0 0 0 1 1 0 1 1 ri= iter(range(3)) for i in ri: for j in ri: print(i,j) # this is somewhat deceptive as the outer loop executes just once 0 1 0 2 I personally would add a 'break' after 'outer_line = next(f)', since the first loop is effectively done anyway at that point, and dedent the second for statement. I find to following clearer ri= iter(range(3)) for i in ri: break for j in ri: print(i,j) # this makes it clear that the first loop executes just once 0 1 0 2 I would only nest if the inner loop could terminate without exhausting the iterator and I wanted the outer loop to then resume. __ Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Is Unicode support so hard...
On 4/20/2013 9:37 PM, rusi wrote: I believe that the recent correction in unicode performance followed jmf's grumbles No, the correction followed upon his accurate report of a regression, last August, which was unfortunately mixed in with grumbles and inaccurate claims. Others separated out and verified the accurate report. I reported it to pydev and enquired as to its necessity, I believe Mark opened the tracker issue, and the two people who worked on optimizing 3.3 a year ago fairly quickly came up with two different patches. The several month delay after was a matter of testing and picking the best approach. -- http://mail.python.org/mailman/listinfo/python-list
Re: suggestion for a small addition to the Python 3 list class
On 4/21/2013 1:12 PM, Lele Gaifax wrote: Robert Yacobellis ryacobel...@luc.edu writes: I've noticed that the str join() method takes an iterable, Specifically, it takes an iterable of strings. Any iterable can be made such iwth map(str, iterable) or map(repr, iterble). so in the most general case I'm suggesting to add a join() method to every Python-provided iterable (however, for split() vs. join() .split *could* have been changed in 3.0 to return an iterator rather than a list, as done with map, filter, and others. An itersplit method *might* be added in the future. it would be sufficient to just add a join() method to the list class). That's the reasoning behind the rejection: to be friendly enough, you'd need to include the join method in the sequence protocol, and implement it on every sequence-like object (be it some kind of UserList, or a generator, or an interator...) Plus, only lists of strings can be joined, not generic lists. This question carries several references to the various threads on the subject: http://stackoverflow.com/questions/493819/python-join-why-is-it-string-joinlist-instead-of-list-joinstring ciao, lele. -- http://mail.python.org/mailman/listinfo/python-list
Re: Include and lib files for Visual Studio?
On 4/20/2013 4:59 PM, xuc...@gmail.com wrote: I am looking for the Python include and lib files for windows. I have a c++ project that I am importing into Visual Studio 2010 (express) and it links python. I need the include and lib files for windows. Where can I get them? I'd like to use python 3.3.1 if possible. I found the msi on python.org but is says they don't include source. I am assuming there is a dev sdk or something similar but can't seem to find it. If you want *everything*, clone hg.python.org/cpython (or something like that). PCBuild has Windows stuff, including VS .sln files. -- http://mail.python.org/mailman/listinfo/python-list
Re: There must be a better way
On 4/20/2013 8:34 PM, Tim Chase wrote: In 2.x, the csv.reader() class (and csv.DictReader() class) offered a .next() method that is absent in 3.x In Py 3, .next was renamed to .__next__ for *all* iterators. The intention is that one iterate with for item in iterable or use builtin functions iter() and next(). -- http://mail.python.org/mailman/listinfo/python-list
Re: Feature Request: `operator.not_in`
On 4/19/2013 10:27 AM, Matthew Gilson wrote: ) It seems to me that the operator module should have a `not_in` or `not_contains` function. It seems asymmetric that there exists a `is_not` function which implements `x is not y` but there isn't a function to represent `x not in y`. There is also no operator.in. There is operator.contains and operator.__contains__. There is no operator.not_contains because there is no __not_contains__ special method. (Your point two, which I disagree with.) 2) I suspect this one might be a little more controversial, but it seems to me that there should be a separate magic method bound to the `not in` operator. The reference manual disagrees. The operator not in is defined to have the inverse true value of in. Currently, when inspecting the bytecode, it appears to me that `not x in y` is translated to `x not in y` (this supports item 1 slightly). However, I don't believe this should be the case. In python, `x y` does not imply `not x = y` because a custom object can do whatever it wants with `__ge__` and `__lt__` -- They don't have to fit the normal mathematical definitions. The reason for this is that the rich comparisons do not have to return boolean values, and do not for numarray arrays which, I believe, implement the operators itemwise. I don't see any reason why containment should behave differently. 'Design by analogy' is tricky because analogies often leave out important details. __contains__ *is* expected to return true/false. object.__contains__(self, item) Called to implement membership test operators. Should return true if item is in self, false otherwise -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Ubuntu package python3 does not include tkinter
On 4/19/2013 1:17 PM, lcrocker wrote: Am I mistaken in my belief that tkinter is a non-optional part of the Python language? Yes. The PSF CPython Windows installer makes installation of tcl/tk/tkinter optional. The build files will compile and build Python without tkinter and without other modules that depend on other c libraries (example, lzma). I believe one can build python 2 without unicode, which is much more 'core' than the Tkinter module. I installed the python3 package on Ubuntu, and tkinter is not included--it's an optional package python3-tk that has to be installed separately. I reported this as a bug as was summarily slapped down. I hope it was done politely ;-). Overall, Ubuntu is relatively advanced in moving to new versions. I believe I read that they are hoping to make 3.3 the default Python as soon as possible. -- http://mail.python.org/mailman/listinfo/python-list
Re: Preparing sqlite, dl and tkinter for Python installation (no admin rights)
On 4/18/2013 12:24 PM, James Jong wrote: After compiling, you might want to run the test suite. libtk8.6.so http://libtk8.6.so I do not know that Python/_tkinter/tkinter has been very well tested, certainly not on all systems, with the newish tcl/tk 8.6, as opposed to 8.5.z used for several years. There are 4 test/test_xxx files to be concerned about: something like test_tcl, test_tkinter, test_ttkxxx. -- http://mail.python.org/mailman/listinfo/python-list
Re: The type/object distinction and possible synthesis of OOP and imperative programming languages
On 4/16/2013 5:07 AM, Antoon Pardon wrote: Op 16-04-13 05:17, Terry Jan Reedy schreef: On 4/15/2013 10:32 PM, Steven D'Aprano wrote: On Mon, 15 Apr 2013 20:52:58 -0400, Terry Jan Reedy wrote: I will keep the above in mind if I write or review a patch. here are 4 non-subclassable builtin classes. Two are already documented. Bool in one, forget which other. I believe it was recently decided to leave the other two as is given the absence of any practical use case. Why should there be a practical use case here? As a practical matter, the change is non-trivial. Someone has to be motivated to write the patch to enable subclassing, write tests, and consider the effect on internal C uses of slice and stdlib Python used of slice (type() versus isinstance). Since classes are in general subclassable, if written in Python, but not if written in C. I once had an idea of a slice-like class that I would have liked to experiment with. Did the idea actually require that instances *be* a slice rather than *wrap* a slice? -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Preparing sqlite, dl and tkinter for Python installation (no admin rights)
On 4/16/2013 10:30 AM, rosoloum wrote: I do not have admin rights on my machine The answer to your question may depend on the OS (linux), distribution (many), and version. What about `_tkinter` and `dl`? How can I have them ready for the Python installer? Building _tkinter (a Python C-coded module) requires tcl/tk and header files. Some distros have a separate python sdk kit with the headers not included with tcl/tk. -- http://mail.python.org/mailman/listinfo/python-list
Re: a couple of things I don't understand wrt lists
On 4/16/2013 11:37 AM, aaB wrote: I represent the CA's rule with a list of integers, of value 1 or 0. Here is the function I use to generate the list: def get_rule(rulenum): rule = [] while rulenum 0: rule.append(rulenume % 2) rulenum /= 2 divmod(rulenum) will return both the quotient and remainder at one time while len(rule) 8: rule.append(0) rule.reverse() return rule In versions of Python with builtin bin(), you could write def get_rule(rulenum): b = bin(rulenum)[2:] # return [0]*(8-len(b)) + [int(i) for i in b] To know Python decently well, you should understand all of that syntax. rule = getrule(int(8)) print rule [0, 0, 0, 0, 1, 0, 0, 0] -- http://mail.python.org/mailman/listinfo/python-list
Re: The node.js Community is Quietly Changing the Face of Open Source
On 4/16/2013 12:02 PM, Rodrick Brown wrote: I came across this article which sums up some of the issues I have with modern programming languages. I've never really looked at Javascript for anything serious or Node itself but I found this article really informational. The “Batteries included” philosophy of Python was definitely the right approach during the mid 90’s and one of the reasons that I loved Python so much; this was a time before modern package management, and before it was easy to find and install community-created libraries. Nowadays Python gets used in places like corporations and schools where one cannot simply install stuff off the net, but must fill out a form asking permission, or maybe not ask at all. though I think it’s counter-productive. Developers in the community rarely want to bother trying to compete with the standard library, so people are less likely to try to write libraries that improve upon it. Except that there is competition for many modules. That said, there are old modules that probably would not be added today, and some the dev would like to remove. (Some were for 3.0.) http://caines.ca/blog/programming/the-node-js-community-is-quietly-changing-the-face-of-open-source/ The irony is that the author goes on to say that the node.js community 'works' because they all use the same infrastructure battery: git and git-hub ;-). -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: The type/object distinction and possible synthesis of OOP and imperative programming languages
On 4/16/2013 1:29 PM, Ethan Furman wrote:
On 04/16/2013 01:25 AM, Serhiy Storchaka wrote:
On 16.04.13 07:46, Ian Kelly wrote:
On Mon, Apr 15, 2013 at 9:17 PM, Terry Jan Reedy tjre...@udel.edu
wrote:
I will keep the above in mind if I write or review a patch. here are 4
non-subclassable builtin classes. Two are already documented. Bool
in one,
forget which other. I believe it was recently decided to leave the
other two
as is given the absence of any practical use case.
The four are bool, NoneType, slice and ellipsis, I believe.
-- import builtins
-- for n in dir(builtins):
... if type(getattr(builtins, n)) is type:
... try:
... t = type(n, (getattr(builtins, n),), {})
... except TypeError as e:
... print(e)
...
type 'bool' is not an acceptable base type
type 'memoryview' is not an acceptable base type
type 'range' is not an acceptable base type
type 'slice' is not an acceptable base type
Well that bumps our count to five then:
-- NoneType = type(None)
-- NoneType
class 'NoneType'
-- class MoreNone(NoneType):
... pass
...
Traceback (most recent call last):
File stdin, line 1, in module
TypeError: type 'NoneType' is not an acceptable base type
'NoneType' is not a builtin name in builtins, which is precisely why you
accessed it the way you did ;-). From issue 17279 (for 3.3):
Attached subclassable.py produces these lists:
Among named builtin classes, these cannot be subclassed:
bool, memoryview, range, slice,
Among types classes, these can be subclassed:
ModuleType, SimpleNamespace,
--
http://mail.python.org/mailman/listinfo/python-list
Re: Missing decimals in the code - some suggestions?
On 4/16/2013 2:02 PM, hmjelte...@gmail.com wrote:
Hi!
I am using ystockquote with the following code:
def get_historical_prices(symbol, start_date, end_date):
Get historical prices for the given ticker symbol.
Date format is 'MMDD'
Returns a nested list.
url = 'http://ichart.yahoo.com/table.csv?s=%s;' % symbol + \
'd=%s' % str(int(end_date[4:6]) - 1) + \
'e=%s' % str(int(end_date[6:8])) + \
'f=%s' % str(int(end_date[0:4])) + \
'g=d' + \
'a=%s' % str(int(start_date[4:6]) - 1) + \
'b=%s' % str(int(start_date[6:8])) + \
'c=%s' % str(int(start_date[0:4])) + \
'ignore=.csv'
days = urllib.urlopen(url).readlines()
data = [day[:-2].split(',') for day in days]
return data
This code prints the data, but only 2 decimals. I need to print out 4 decimals.
As far as I know, prices are only defined to the nearest penny* (2
decimals) so I don't know what more you expect.
*Not too long ago, prices were in 1/8ths of a dollar. Market makers
complained about decimalization because it would squeeze the spread that
they profited from -- which it did.
print ystockquote.get_historical_prices('EURUSD=X','20120101','20120301')
Some suggestions?
--
http://mail.python.org/mailman/listinfo/python-list
Re: Understanding Boolean Expressions
[2nd try, quotation a bit messed up] On 4/16/2013 6:19 PM, Bruce McGoveran wrote: Hello. I am new to this group. I've done a search for the topic about which I'm posting, and while I have found some threads that are relevant, I haven't found anything exactly on point that I can understand. So, I'm taking the liberty of asking about something that may be obvious to many readers of this group. The relevant Python documentation reference is: http://docs.python.org/2/reference/expressions.html#boolean-operations. I'm trying to make sense of the rules of or_test, and_test, and not_test that appear in this section. While I understand the substance of the text in this section, The substance is that 1) 'not' binds tighter than 'and' binds tigher than 'or' and 2) 'and' and 'or' both associate left to right in the normal manner so that 'a op b op c' == '(a op b) op c'. it is the grammar definitions themselves that confuse me. The techinical details reflect the fact that Python's grammar is ll(1) (top-down, parsed by recursive descent) rather than lr(1) (bottom-up). The latter (in lalr(1) form) is what yacc, etc use and might be more familiar to you. For example, I am not clear how an or_test can be an and_test. or_test ::= and_test | or_test or and_test The second option expresses the associativity rule, but more is needed to get out of infinite regress. Substituting the second rule into second rule gives or_test = (or_test 'or' and_test) 'or' and_test and so on. At some point, one must replace or_test with and_test to get an 'or' of ands. Similarly, an and_test must resolve to an 'and' of nots. Moreover, if I follow the chain of non-terminal references, I move from or_test, to and_test, to nt_test, to comparison. And when I look at the definition for comparison, I seem to be into bitwise comparisons. I cannot explain this. Eventually the chain takes one to primaries, which include things like literals and identifiers. Perhaps an example will help put my confusion into more concrete terms. Suppose I write the expression if x or y in my code. I presume this is an example of an or_test. Yes. Beyond that, though, I'm not sure whether this maps to an and_test (the first option on the right-hand side of the rule) or to the or_test or and_test option (the second on the right-hand side of the rule). The second. Then the or_test on the left also maps to an and_test. Each and_test eventually resolves to 'identifier', specifically 'x' and 'y'. -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Cross-compiling Python for ARM?
On 4/15/2013 11:20 AM, Gilles wrote: Hello I tried running uWSGI on an ARM-based appliance, but it fails. Apparently, it could be due to the official Python 2.6.6 interpreter in the depot not being compiled the way uWSGI expects it to be: ./configure --enable-shared; make; make install; www.raspberrypi.org/phpBB3/viewtopic.php?f=32t=15370 I see Python mentioned in /usr/lib and /usr/share, and was wondering if all it'd take to solve this issue, is just to cross-compile the interpreter and the rest is just CPU-agnostic Python scripts. Just in case, here's the output: www.pastebin.com/wJHjBrfn I believe some cross-compile support was added to 2.7.4 but I do not know the exact nature. -- http://mail.python.org/mailman/listinfo/python-list
Re: The type/object distinction and possible synthesis of OOP and imperative programming languages
On 4/15/2013 1:43 PM, Antoon Pardon wrote: $ python3 Python 3.2.3 (default, Feb 20 2013, 17:02:41) [GCC 4.7.2] on linux2 Type help, copyright, credits or license for more information. class vslice (slice): ... pass ... Traceback (most recent call last): File stdin, line 1, in module TypeError: type 'slice' is not an acceptable base type It seems types and classes are still not mere synonyms. Some builtin classes cannot be subclassed. There is an issue to document which better. That does not mean that it is not a class. -- http://mail.python.org/mailman/listinfo/python-list
Re: The type/object distinction and possible synthesis of OOP and imperative programming languages
On 4/15/2013 10:32 PM, Steven D'Aprano wrote: On Mon, 15 Apr 2013 20:52:58 -0400, Terry Jan Reedy wrote: Some builtin classes cannot be subclassed. There is an issue to document which better. That does not mean that it is not a class. I think it is also important to document whether that is a language feature, or a mere restriction of the implementation. There is an important distinction to be made between: In CPython, you cannot subclass slice or FunctionType. Other Pythons may have more, or fewer, restrictions. and: No language that calls itself Python is permitted to allow slice and FunctionType to be subclassable. If I had a say in this, I would vote for the first case, with the possible exception of documented singleton types like NoneType and bool. I will keep the above in mind if I write or review a patch. here are 4 non-subclassable builtin classes. Two are already documented. Bool in one, forget which other. I believe it was recently decided to leave the other two as is given the absence of any practical use case. -- http://mail.python.org/mailman/listinfo/python-list
Re: The type/object distinction and possible synthesis of OOP and imperative programming languages
Note: cross-posting to mailing lists does not work well. Hence the reply only to python-list and the gmane mirror. On 4/14/2013 11:48 PM, Mark Janssen wrote: Python is an interpreted language. I consider this a useless or even deceptive statement. Python is an object-based algorithm language. The CPython implementation (currently) *compiles* Python code to a virtual machine bytecode, similar to Java bytecode. This could change. Jython translates to Java, which is then compiled to Java bytecode. Do you call Java an 'interpreted' language? There are compilers that compile Python to the same 'object code' that C is compiled to. Since 2001, Python's has migrated towards a pure Object model. It migrated towards a pure class model. model (ref: http://www.python.org/download/releases/2.2/descrintro/). Prior to then, it had both types and classes and these types were anchored to the underlying C code and the machine/hardware architecture itself. I started with Python 1.3 and I have no idea what you mean by this. I think you are heavily confusing Python the language and CPython the implementation. After the 2001 type/class unification , it went towards Alan Kay's ideal of everything is an object. Everything has always been an object with value and identity. This stands in contrast to the assemble/C model that everything (except registers) is a block of linear memory with an address. My question is: Is there something in the Computer Science literature that has noticed this distinction/development in programming language design and history? To me, there should be, since this is a fundamental distinction in data models. I think the biggest problem in shifting from C to Python is 'getting' the data model difference. For Lispers, the difference is the syntax. -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: API design for Python 2 / 3 compatibility
On 4/13/2013 12:36 PM, Stefan Schwarzer wrote: Hello, I'm currently changing the FTP client library ftputil [1] so that the same code of the library works with Python 2 (2.6 and up) and Python 3. (At the moment the code is for Python 2 only.) I've run into a API design issue where I don't know which API I should offer ftputil users under Python 2 and Python 3. [1] http://ftputil.sschwarzer.net/ Some important background information: A key idea in ftputil is that it uses the same APIs as the Python standard library where possible. For example, with ftputil you can write code like this: with ftputil.FTPHost(host, user, password) as ftp_host: # Like `os.path.isdir`, but works on the FTP server. if ftp_host.path.isdir(hello_dir): # Like `os.chdir`, but works on the FTP server. ftp_host.chdir(hello_dir) # Like the `open` builtin, but opens a remote file. with ftp_host.open(new_file, w) as fobj: # Like `file.write` and `file.close` fobj.write(Hello world!) fobj.close() Since most of Python 2's and Python 3's filesystem-related APIs accept either bytes and character strings (and return the same type if they return anything string-like at all), the design here is rather clear to me. However, I have some difficulty with ftputil's counterpart of the `open` builtin function when files are opened for reading in text mode. Here are the approaches I've been thinking of so far: * Approach 1 When opening remote text files for reading, ftputil will return byte strings from `read(line/s)` when run under Python 2 and unicode strings when run under Python 3. Pro: Each of the Python versions has ftputil behavior which matches the Python standard library behavior of the respective Python version. Con: Developers who want to use ftputil under Python 2 _and_ 3 have to program against two different APIs since their code inherits ftputil's duality. Con: Support for two different APIs will make the ftputil code (at least a bit) more complicated than just returning unicode strings under both Python versions. * Approach 2 When opening remote text files for reading, ftputil will always return unicode strings from `read(line/s)`, regardless of whether it runs under Python 2 or Python 3. Pro: Uniform API, independent on underlying Python version. Pro: Supporting a single API will result in cleaner code in ftputil than when supporting different APIs (see above). Con: This approach might break some code which expects the returned strings under Python 2 to be byte strings. Con: Developers who only use Python 2 might be confused if ftputil returns unicode strings from `read(line/s)` since this behavior doesn't match files opened with `open` in Python 2. Which approach do you recommend and why do you prefer that approach? Are there other approaches I have overlooked? Do you have other suggestions? Approach 2 matches (or should match) io.open, which became builtin open in Python 3. I would simply document that ftp_host.open mimics io.open in the same way that ftp_host.chdir, etcetera, match os.chdir, etc. Your principle will remain intact. Anyone writing *new* Py 2 code with any idea of ever running on Py 3 should be using io.open anyway. That is why it was backported. You might be able to reuse some io code or subclass some io classes for your implementation. -- http://mail.python.org/mailman/listinfo/python-list
Re: shutil.copyfile is incomplete (truncated)
On 4/12/2013 3:32 AM, Chris Angelico wrote: On Fri, Apr 12, 2013 at 4:25 PM, Rob Schneider rmsc...@gmail.com wrote: The close method is defined and flushing and closing a file, so it should not return until that's done. What command are you using to create the temp file? re command to write the file: f=open(fn,'w') ... then create HTML text in a string f.write(html) f.close Hold it one moment... You're not actually calling close. The file's still open. Is that a copy/paste problem, or is that your actual code? In Python, a function call ALWAYS has parentheses after it. Evaluating a function's name like that returns the function (or method) object, which you then do nothing with. (You could assign it someplace, for instance, and call it later.) Try adding empty parens: f.close() and see if that solves the problem. Alternatively, look into the 'with' statement and the block syntax that it can give to I/O operations. I say *definitely* use a 'with' statement. Part of its purpose is to avoid close bugs. -- http://mail.python.org/mailman/listinfo/python-list
Re: name lookup failure using metaclasses with unittests
On 4/12/2013 3:17 AM, Ulrich Eckhardt wrote:
Am 11.04.2013 10:19, schrieb Steven D'Aprano:
if sys.version = '3':
Use sys.version_info = (3,), otherwise your code breaks when upgrading
to Python 10 and greater. ;^)
The second question that came up was if there is a way to keep a
metaclass defined inside the class or if the only way is to provide it
externally. [...]
Not in general, since the metaclass has to exist independently of the
class.
Thanks for your explanations, they are appreciated.
The class is an instance of your metaclass. That means that the
metaclass must exist first, so it can be instantiated when you
define the class.
I don't like the approach to define the code to post-process a class
before defining the class. It's a bit like top-posting, it messes up the
reading order. Since I really intend to post-process the class, it seems
that metaclasses are simply not the right tool.
Using a post-processing object as a metaclass or decorator necessarily
requires predefinition. Such objects are usually used more than once.
For one-off postprocessing, I probably would not bother.
At the moment, this leaves me with two options:
1. post-process the class
class X:
pass
# attach constants to clas X
for i in (1, 2, 3):
setattr(X, 'f{}' % i, i)
2. generate code inline
class Y: pass
# generate constants in local (class-)namespace
for i in (1, 2, 3):
locals()['f{}' % i] = i
Mutating class locals() currently works in CPython, but is explicitly
not guaranteed to work by the language definition.
In both cases, variables (loop variable 'i') are leaked into the
surrounding namespace, which is kind-of ugly. The second approach also
seems a bit hackish and I can't use the class-in-definition there, which
is limiting when you want to attach e.g. constants of type X to X.
Also PEP 3115 Metaclasses in Python 3000[2] seems to
consider postprocessing of a class definition as better handled by a
class decorator, which is something I haven't looked at yet.
Generally, class decorators are less brain-melting than metaclasses.
Alas, they also need to be defined before the class, messing with the
mentioned order of declaration. They can be used to call a class
function though which then does the necessary postprocessing...
3. post-process the class triggered with decorator
def postprocess_class(cls):
invoke postprocess() on the decorated object
cls.postprocess()
del cls.postprocess
return cls
@postprocess_class
class Z:
@classfunction
def postprocess(cls):
# attach constants to class
for i in (1, 2, 3):
setattr(cls, 'f{}' % i, i)
I guess I'll stay with variant 1 for now, since it requires the least
amount of code and the least amount of questions from other developers
here.
--
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Re: SimpleHTTPRequestHandler used with HTTP/1.1 hangs after the second resource on a page.
On 4/12/2013 4:46 PM, Piotr Dobrogost wrote:
Hi!
I'd like to bring your attention to the question titled Use HTTP/1.1
with SimpleHTTPRequestHandler at
http://stackoverflow.com/q/15839718/95735 which reads; When I use
I find the doc slightly confusing. The SO code uses BaseHTTPServer. The
doc says Usually, this module isn’t used directly, On the other hand,
SimpleHTTPServer only defines a request handler and not a server itself.
HTTP/1.1 with SimpleHTTPRequestHandler, loading a page that pulls in
other resources will hang after the second resource. and there's a
What does 'hang' mean? Does the page get displayed? If so,
server.serve_forever is supposes to 'hang'.
tiny test showing the problem. It's hard to believe that
SimpleHTTPServer doesn't handle such a simple task, does it? If I
checked correctly code is stuck in handle_one_request() method at
line 370 of server.py
(http://hg.python.org/cpython/file/d9893d13c628/Lib/http/server.py#l370)
but I can't see what's wrong. Any ideas?
The SO post says
class MyRequestHandler(SimpleHTTPRequestHandler):
#protocol_version = HTTP/1.0 # works
protocol_version = HTTP/1.1 # hangs
so this should be some sort of clue. The code says
569 # The version of the HTTP protocol we support.
570 # Set this to HTTP/1.1 to enable automatic keepalive
571 protocol_version = HTTP/1.0
The only substantive code I found using protocol_version (in the CPython
default branch you linked to) is
300 if version_number = (1, 1) and self.protocol_version = HTTP/1.1:
301 self.close_connection = 0
331 elif (conntype.lower() == 'keep-alive' and
332 self.protocol_version = HTTP/1.1):
333 self.close_connection = 0
334 # Examine the headers and look for an Expect directive
335 expect = self.headers.get('Expect', )
336 if (expect.lower() == 100-continue and
337 self.protocol_version = HTTP/1.1 and
338 self.request_version = HTTP/1.1):
339 if not self.handle_expect_100():
340 return False
I would re-test with the recently released 3.3.1 (and/or 2.7.4) to make
sure nothing has changed
--
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Re: Python module vs library
On 4/9/2013 5:58 AM, k.lykour...@gmail.com wrote: Hi, what is the difference between python module and library ? They are in different categories. A Python module is a namespace (a mapping of names to objects) created by running Python code as a main module or by import statements within Python code (or by executing import functions within a Python interpreter). A library in general is a collection of functions and classes used by multiple applications. A Python library is composed of Python modules, packages, and collections of such. -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie question about confusing exception handling in urllib
On 4/9/2013 7:41 AM, cab...@gmail.com wrote: Hi, I have been using Java/Perl professionally for many years and have been trying to learn python3 recently. As my first program, I tried writing a class for a small project, and I am having really hard time understanding exception handling in urllib and in python in general... Basically, what I want to do is very simple, Very funny ;-). What you are trying to do, as your first project, is interact with the large, multi-layered, non=deterministic monster known as Internet, with timeout handling, through multiple layers of library code. When it comes to exception handling, this is about the most complex thing you can do. try to fetch something tryurllib.request.urlopen(request), and: - If request times out or connection is reset, re-try n times - If it fails, return an error - If it works return the content. But, this simple requirement became a nightmare for me. I am really confused about how I should be checking this because: - When connection times out, I sometimes get URLException with reason field set to socket.timeout, and checking (isinstance(exception.reason, socket.timeout)) works fine - But sometimes I get socket.timeout exception directly, and it has no reason field, so above statement fails, since there is no reason field there. If you are curious why the different exceptions for seemingly the same problem, you can look at the printed traceback to see where the different exceptions come from. Either don't catch the exceptions, re-raise them, or explicitly grab the traceback (from exc_info, I believe) - Connection reset is a totally different exception - Not to mention, some exceptions have msg / reason / errno fields but some don't, so there is no way of knowing exception details unless you check them one by one. The only common thing I could was to find call __str__()? The system is probably a bit more ragged then it might be if completely re-designed from scratch. - Since, there are too many possible exceptions, you need to catch BaseException (I received URLError, socket.timeout, ConnectionRefusedError, ConnectionResetError, BadStatusLine, and none share a common parent). And, catching the top level exception is not a good thing. You are right, catching BaseException is bad. In particular, it will catch KeyboardInterrupt from a user trying to stop the process. It is also unnecessary as all the exceptions you want to catch are derived from Exception, which itself is derived from BaseException. So, I ended up writing the following, but from everything I know, this looks really ugly and wrong??? try: response = urllib.request.urlopen(request) content = response.read() except BaseException as ue: except Exception as ue: if (isinstance(ue, socket.timeout) or (hasattr(ue, reason) and isinstance(ue.reason, socket.timeout)) or isinstance(ue, ConnectionResetError)): print(REQUEST TIMED OUT) or, something like: except: except Exception: (a1,a2,a3) = sys.exc_info() errorString = a2.__str__() if ((errorString.find(Connection reset by peer) = 0) or (errorString.find(error timed out) = 0)): -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: The usage of -m option of python
On 4/8/2013 10:50 AM, Albert van der Horst wrote: In article mailman.3484.1363662214.2939.python-l...@python.org, Terry Reedy tjre...@udel.edu wrote: On 3/18/2013 5:17 PM, Peng Yu wrote: Hi, I don't quite understand how -m option is used. And it is difficult to search for -m in google. Could anybody provide me with an example on how to use this option? python -m test at a command line runs the regression tests in the test package python -m test -v test_difflib runs test.test_difflib in verbose mode. I get for both : /usr/bin/python: test is a package and cannot be directly executed. What gives? (Official stable Debian distribution. Python 2.7) For me, 3.3 is default Python. Look in the 2.7 doc for 'test' and I believe it will tell you that you need to write 'test.regrtest'. tjr -- http://mail.python.org/mailman/listinfo/python-list
Re: Interactive development in Python à la Smalltalk?
On 4/8/2013 4:33 AM, Bienlein wrote: Hello, I'm absolutely new to Python, just looked at the language description for the first time. The first thought that came to my mind was whether you can program in Python in an interactive programming style, i.e. I can change code in the debugger which becomes immediately effective (no edit-compile loop) and I can also send messages to objects visible inside the debugger. The CPython interpreter has both a 'batch' mode (run code in a file) and an interactive mode (run code typed in response to a prompt). It also has a '-i' option to run code in batch mode and then switch to interactive mode so one can interrogate visible objects and call functions. The Idle IDE has editor windows linked to an interactive shell. When you run code in the editor window, it saves and runs it with the -i option so you can interactive with the results in the Shell. Compiling edited text to bytecode is typically so fast (well under a second) as to not be an issue. Then Python could become my replacemenet for my dearly missed Smalltalk, which to my great grief meanwhile really has become quite dead, I fear. In Smalltalk you can open up an inspector window (e.g. you don't have to get into debug mode), inspect objects in it and evaluate code in it, send messaages to objects. I guess this cannot be done in Python out of the box. But if changes made in the debugger became immediately effective, this would be interactive enough for my purposes. Idle also has a debugger window that does some of that, though it works better on non-Windows OSes. I have never actually used it. --- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: How do I tell if I'm running under IDLE?
On 4/5/2013 5:30 AM, Steven D'Aprano wrote:
I'm looking for an official way to tell what interpreter (if any) is
running, or at least a not-too-horrible unofficial way.
The interpreters distributed by PSF identify themselves on startup, as
least in interactive mode, by displaying a line like Python 3.3.0+
(default, Mar 30 2013, 17:36:11) [MSC v.1600 32 bit (Intel)] on win32
The version available as sys.version, sys.hexversion, and
sys._version(). The platform is available as sys.platform. The compiler
and compile date are not officially available.
But you seem not to be actually asking 'what interpreter is running' but
'who started the interpreter' and 'is the interpreter i/o connected to a
text-mode OS console or to a gui program, such as IDLE, more or less
simulating an OS console.
There is no official way because it should not matter to a running
program. It is the goal of at least some IDLE developers to make the
connection to the IDLE shell as transparent as possible to Python code,
so that it matters as little as possible*. This is one reason for the
shift from running user code in the same process and interpreter
instance as Idle to running user code in a separate process with its own
interpreter instance.
* There are current tracker issues about making this true. We really do
not want people to have to write conditional code, unless it is to work
around a console problem if Idle is not being used ;-).
If you have an issue not already covered on the tracker, I am curious
what it is.
Googling comes up with a number of hacks for detecting IDLE. Some of them
are terrible. For example, I can't believe that somebody actually
suggested this:
if len(sys.modules) 20:
print running under IDLE
This is based on the fact that if running in the same process, there are
a lot more imported modules and if running in a separate process, there
are at least a few more imported modules to set up the rpc connection. I
do not know that '20' is particularly reliable, even on startup.
This one is better, but still not exactly what I consider great:
Why not, if is works for all Idle versions so far? The irreducible
effect of any non-OS-console environment is to override the normal i/o.
sys.stdin.__class__.__module__.startswith('idlelib')
'idlelib' in sys.stdin.__class__.__module__' is possibly more future-proof.
Ideally, I'd like to detect any arbitrary environment such as Spyder,
IPython, BPython, etc., but will settle for just IDLE.
I expect that looking as sys.stdin in someway should work for all.
--
Terry Jan Reedy
--
http://mail.python.org/mailman/listinfo/python-list
Re: problem in running a basic code in python 3.3.0 that includes HTML file
On 4/4/2013 3:08 PM, Satabdi Mukherjee wrote: i have written this code and i need to run this file def CreateEvent(str): Using the builtin name 'str' as a parameter name is a bad idea. Use 's' or 'string' or something instead. This prints a passed string into this function; The line above has to be indented. Leave off the trailing ';' print str; This is not valid in Python 3, where print() is a function This line would have to be 'print(s)'. However, the function as written is senseless; just call print() directly. return; And empty return at the end does nothing. There is already an implicit 'return None' at the end of every function. CreateEvent (print''' delete 'print' -- it is another syntax error. content-type: text/html html head title the list of all possible events that can be notified by our system /title /head body form input type=checkbox name=tsunami value=tsunamitsunamibr input type=checkbox name=earthquake value=earthquakeearthquakebr input type=checkbox name=volcano value=volcanovolcanobr input type=checkbox name=hurricane value=hurricanehurricanebr input type=checkbox name=sinkholes value=sinkholessinkholesbr input type=checkbox name=tornado value=tornadotornadobr input type=checkbox name=landslide value=landslidelandslidebr input type=checkbox name=downburst value=downburstdownburstbr /form input type=submit value=Submit /body /html ''') -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Performance of int/long in Python 3
On 4/3/2013 1:32 AM, Steven D'Aprano wrote: On Wed, 03 Apr 2013 14:31:03 +1100, Neil Hodgson wrote: Sorting a million string list (all the file paths on a particular computer) went from 0.4 seconds with Python 3.2 to 0.78 with 3.3 so we're out of the 'not noticeable by humans' range. Perhaps this is still a 'micro-benchmark' - I'd just like to avoid adding email access to get this over the threshold. What system *and* what compiler and compiler options. Unless 3.2 and 3.3 are both compiler with the same compiler and settings, we do not know the source of the difference. I cannot confirm this performance regression. On my laptop (Debian Linux, not Windows), I can sort a million file names in approximately 1.2 seconds in both Python 3.2 and 3.3. There is no meaningful difference in speed between the two versions. I am guessing that Neil's undisclosed system (that I can see) is Windows, since other benchmarks have been more different on Windows than on *nix. Given that we *know* that the 3.2 and 3.3 distribution are compiled with different compilers and run with different C runtimes, it is possible that some of the difference is from that and not from python at all. tjr -- http://mail.python.org/mailman/listinfo/python-list
Re: Python install Win 7 Problem
On 4/3/2013 1:51 PM, Martin Schöön wrote: On 2013-04-02, balasubramanian Achuthan balasu...@gmail.com wrote: Try using Activestate python. The free version would suffice your needs and it comes with a clean install. I have been travelling and have not had time to read this thread in detail so this may be old hat but on Windows (at work) I simply install Python(x,y) https://code.google.com/p/pythonxy/ Only available for 2.x -- http://mail.python.org/mailman/listinfo/python-list
Re: IDLE printing problem
On 4/3/2013 12:24 PM, Joe Hill wrote: On 4/3/2013 12:24 PM, Joe Hill wrote: I attempted to print about 10 pages of documentation from the help files using IDLE. On all the pages the side of each page was missing about 1/4 inch of text. You neglected to say what you actually did to have a problem. I tried the following with the font set to the default Courier. help(tuple) a page and a half of help text print to Canon inkjet or HP Laserjet 5 Everything printed, with longest lines just fitting within the margins. Am I missing a setting? Is this a known problem? Will it do the same with lines of code? Printing depends on font, font size, OS printer driver, and printer. I suspect Idle just sends print command to tk text widget. Its 'print dialog' is as primitive as possible: the only choice is to print to the default printer or not; no printer choice, no page setup. Tk, in turn, should just put the text in a temporary file and turn it over to the OS printer driver. Using W7, 64 bit. PY 3.3. It worked just fine when I pasted the text in Word 2010. I am sure it is has more knowledge about the vagaries of printing. You might try a single page (with max length lines) after Word prints to see if it left the printer in a better state. -- http://mail.python.org/mailman/listinfo/python-list
Re: IDLE printing problem
On 4/3/2013 2:50 PM, Joe Hill wrote: On Wed, 03 Apr 2013 14:40:38 -0400, Terry Jan Reedy tjre...@udel.edu wrote: On 4/3/2013 12:24 PM, Joe Hill wrote: I attempted to print about 10 pages of documentation from the help files using IDLE. On all the pages the side of each page was missing about 1/4 inch of text. You neglected to say what you actually did to have a problem. Text that I needed to make sense of the page did not print from the help file. Characters were missing on the right side on every long line on every page. I got that already. Until you say what you did, in enough detail to reproduce your actions, I cannot comment further. -- http://mail.python.org/mailman/listinfo/python-list
Re: Time zone changing while Win app is running
On 4/3/2013 2:46 PM, CM wrote: On Apr 3, 7:37 am, Steven D'Aprano steve +comp.lang.pyt...@pearwood.info wrote: On Tue, 02 Apr 2013 17:04:12 -0700, CM wrote: To summarize the issue: In an application, I have been using Python's datetime module to get the current time. But it seems that, at least with Windows (XP), whatever time zone your computer is set to when you start the application, that's what datetime will use--the time zone will *not* be updated in the application when you update it manually with Windows. So, if you change the time zone (say, after traveling with your laptop), all datetimes will be incorrect as compared to your system clock. I am not the maintainer of the datetime module, but based purely on what you have said, I would consider that a bug. I don't. Do you really want every time function slowed by re-initializing the timezone? I suggest you report it as an issue on the Python bug tracker. I do believe that time.tzget can now be make to work now on Windows, and that would be a proper tracker issue. Thanks, I submitted an issue about it. On 2.7.3, on Windows, it's easy to demonstrate: (Actual time = 2:40pm; tz = Eastern U.S.) import datetime print datetime.datetime.now() 2013-04-03 14:40:03.124000 RIGHT (Now change time zone to UTC, for example. Now clock reads 6:41pm.) import datetime Without a restart, this is a no=op. print datetime.datetime.now() 2013-04-03 14:41:13.124000 WRONG As I said on the issue, passing a tz arg to now() will give the answer for any timezone on earth. A user-friendly app displaying times should let users choose. -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: IDLE printing problem
On 4/3/2013 5:16 PM, Joe Hill wrote: On Wed, 03 Apr 2013 16:20:20 -0400, Terry Jan Reedy tjre...@udel.edu wrote: On 4/3/2013 2:50 PM, Joe Hill wrote: On Wed, 03 Apr 2013 14:40:38 -0400, Terry Jan Reedy tjre...@udel.edu wrote: On 4/3/2013 12:24 PM, Joe Hill wrote: I attempted to print about 10 pages of documentation from the help files using IDLE. On all the pages the side of each page was missing about 1/4 inch of text. You neglected to say what you actually did to have a problem. Text that I needed to make sense of the page did not print from the help file. Characters were missing on the right side on every long line on every page. I got that already. Until you say what you did, in enough detail to reproduce your actions, I cannot comment further. I Open IDLE and click on Help and select the second option which is Documentation - select Glossary. The three options I see are 1) 'About Idle', 2) 'Idle help', which brings as a 2 page doc starting [See the end of this file for ** TIPS **, and 3) Python Docs - F1. On Windows, this third option brings up Windows Help opened to the windows-help version of the docs, which are also available online in a browser. In either case, Glossary is one of the docs. We have left IDLE so your problem has nothing to do with IDLE. On Windows, one can open the same doc from the Start menu by selecting Python x.y / Python Docs. I then click on the Print icon at the top of the Help/Documentation screen - then let er rip. The word/line wrap on the screen is ok and the printed output is not. The word wrap on the screen adjusts to the window width. With the window too wide for the printer, I selected about five paragraphs, printed the selection, and the text was properly re-wrapped for printing with nothing lost, as if the display window had been narrowed. Windows obvious knows how wide the virtual window is for the particular combination of font (about 14 pt proportional sans serif) and printer. Apparently it is mis-calculating for your font and printer combination. This was all unexpected outcomes. I appreciate your help and that perhaps a fix can be found for everyone. Mine is a very standard setup W7 Ult, 64bit and an Epson printer (WP-4020) I have 64 bit Win7 pro with Canon and HP printers. The help window with a sheet+? icon in the upper left is Microsoft's program. The only thing I can suggest is to check for updated drivers, and make sure you have the correct driver. -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Windows printing problem (was re; IDLE printing problem_
On 4/3/2013 6:26 PM, Joe Hill wrote: In light of the fact that this is a new problem and has only occurred in Python - I shall just regard that as either a feature or flaw... Based on what you have said, the problem IS NOT OCCURRING IN PYTHON. It is occurring in the Microsoft HTML help viewer. -- http://mail.python.org/mailman/listinfo/python-list
Re: Data storage Py 3.3
On 4/3/2013 6:53 PM, Irmen de Jong wrote: On 4-4-2013 0:33, Joe Hill wrote: IDLE wants to use Python33 as the data storage folder - with exe files etc. Typically the 'default data storage' is in 'last used' directory or most programs even have a browse setting that one can quickly set and reset. What do people here generally do? When I installed 3.3, (W7- 64) I selected the first option for paths etc. and everything seems to just run fine I have a c:\Programs folder where I put multiple versions of python and selected other programs whose directories I might want to visit. Don't store your files in the Python33 directory even though it is idle's default suggestion. I once did that, but then I had to move stuff when the Python x.y directory became obsolete. It was also a problem when I wanted to test a file with more than one python version. I have my Python code sitting in appropriate subdirectories of a 'Projects' folder somewhere (on a different drive on my Windows system, or just a subfolder in my homedirectory on my Linux VM). I have a file tem.py in my miscellaneous python directory. When I am writing possibly throwaway code, I open it from the recent files list, empty the old code, and go. I can always save as another name if I want to keep the code. tem.py is almost always on the list because I use it frequently. -- http://mail.python.org/mailman/listinfo/python-list
Re: Fwd: Python subdomains https
On 4/2/2013 7:05 AM, Jakub Muszynski wrote: Hi, I need to add python.org http://python.org https to my company firewall policy, but I'm not allowed to add rule for https://*.python.org http://python.org subdomains. Can You give me/publish list of important subdomains (like https://pypi.python.org) so I won't miss important sites? docs - for the online docs bugs - for the issue tracker hg - for the source repository svn - for the external dependencies for building python You could also try all the links on python.org to see if there is anything else. psf.python.org? or is it only python.org/psf? Python.org is getting a facelift under a paid contract, so things might change in the future. I believe the trend is toward more sugdomains. --Terry -- http://mail.python.org/mailman/listinfo/python-list
