Re: optional types
Am I the only one who'd like to see optional types introduced in Python? Nope! Some dude named Guido would like to see them as well: https://mail.python.org/pipermail/python-ideas/2014-August/028742.html -- https://mail.python.org/mailman/listinfo/python-list
Re: Template language for random string generation
On 08/08/2014 01:45 PM, cwolf.a...@gmail.com wrote: On Friday, August 8, 2014 10:35:12 AM UTC-4, Skip Montanaro wrote: P.S. Probably a topic for a separate thread, and not actually Python-related, but on a related note, I have never found a free password keeper which works on all my platforms (Mac, Android, Unix). That is one stumbling block (for me) to actually using extremely strong passwords. If you have some thoughts, please contact me off-list. Skip - try lastpass.com it's cross platform, include Win, Mac, Linux, Android and iOS. LastPass is pretty nice (and I use it on Windows, Mac, Linux and Android myself), but the mobile versions aren't free: https://lastpass.com/misc_download2.php -- https://mail.python.org/mailman/listinfo/python-list
Re: Python's re module and genealogy problem
On 06/11/2014 10:35 AM, Michael Torrie wrote: On 06/11/2014 06:23 AM, BrJohan wrote: For some genealogical purposes I consider using Python's re module. Rather many names can be spelled in a number of similar ways, and in order to match names even if they are spelled differently, I will build regular expressions, each of which is supposed to match a number of similar names. You might want to search for fuzzy matching algorithms. Years ago, there was an algorithm called soundex that would generate fuzzy fingerprints for words that would hide differences in spelling, etc. Unfortunately such an algorithm would be language dependent. The problem you are trying to solve is one of those very hard problems in computers and math. Soundex is actually not horrible, but it is definitely only for English names. Newer variants of Metaphone (http://en.wikipedia.org/wiki/Metaphone) are significantly better, and support quite a few other languages. Either one would most likely be better than the regex approach. Side note: if your data happens to be in MySQL then it has a builtin sounds_like() function that compares strings using soundex. -- https://mail.python.org/mailman/listinfo/python-list
RE: kivy
Is kivy listed in the Python search paths (sys.path)? yes To be extra sure, you can start a python interpreter with the commandline argument -vv, and when you try to import kivy (or any module) it will show you every file/path it checks when trying to find it. This might help you narrow down where the problem lies. -Nick Cash -- https://mail.python.org/mailman/listinfo/python-list
RE: the Gravity of Python 2
and %s (which is incredibly useful) is not even documented (I suspect it's also not available on all platforms). The format specifiers available to Python are just whatever is available to the underlying c time.h. The manpage for strftime indicates that %s isn't part of the C standard, but part of Olson's timezone package, which means it's not available on Windows. Your suspicion is unfortunately correct. -- https://mail.python.org/mailman/listinfo/python-list
RE: cascading python executions only if return code is 0
assert assertions_working() # refuse to run in -O mode Can't imagine why that wouldn't work.. Why overthink this? assert not sys.flags.optimize is clearly the one, and only one, obvious way to do it. Of course, it works about as well as the rest of these solutions. Which is to say, not at all. -Nick Cash -- https://mail.python.org/mailman/listinfo/python-list
RE: Does Python optimize low-power functions?
My question is, what do Python interpreters do with power operators where the power is a small constant, like 2? Do they know to take the shortcut? Nope: Python 3.3.0 (default, Sep 25 2013, 19:28:08) [GCC 4.7.2] on linux2 Type help, copyright, credits or license for more information. import dis dis.dis(lambda x: x*x) 1 0 LOAD_FAST0 (x) 3 LOAD_FAST0 (x) 6 BINARY_MULTIPLY 7 RETURN_VALUE dis.dis(lambda x: x**2) 1 0 LOAD_FAST0 (x) 3 LOAD_CONST 1 (2) 6 BINARY_POWER 7 RETURN_VALUE The reasons why have already been answered, I just wanted to point out that Python makes it extremely easy to check these sorts of things for yourself. -- https://mail.python.org/mailman/listinfo/python-list
RE: chunking a long string?
I have a long string (several Mbytes). I want to iterate over it in manageable chunks This is a weirdly common question. See http://stackoverflow.com/questions/312443/how-do-you-split-a-list-into-evenly-sized-chunks-in-python for several solutions. It's been proposed to be added to itertools before, but rejected: https://mail.python.org/pipermail/python-ideas/2012-July/015671.html and http://bugs.python.org/issue13095 - Nick Cash -- https://mail.python.org/mailman/listinfo/python-list
RE: How to tell an HTTP client to limit parallel connections?
What I really need is an HTTP header or meta-tag or something that I can use to tell clients to limit themselves to a single connection. I don't think such a thing exists... but you may be able to solve this creatively: A) Set up a proxy server that multiplexes all of the connections into a single one. A reverse proxy could even handle the SSL and alleviate the load on the embedded server. Although it sounds like maybe this isn't an option for you? OR B) Redesign the page it generates to need fewer requests (ideally, only one): inline CSS/JS, data: url images, etc. It's not the prettiest solution, but it could work. -Nick Cash -- https://mail.python.org/mailman/listinfo/python-list
RE: Code golf challenge: XKCD 936 passwords
# Python-2, sorry
import os
print list(set(open('/usr/share/dict/words')))[os.getpid():][:4]
So that steps by your pid?
Not really. It seems to rely on list(set(...)) kinda randomizing order... which
is definitely not safe without hash randomization.
But this brings up an interesting concept... if we can assume Python 2.7 with
the -R flag, or Python 3.3+, I think we do get true pseudo-randomization out of
list(set(...))... which means we can trim some!
print(list(set(open('/usr/share/dict/words')))[:4])
No module imports needed! Although it's not as pretty as the original post, but
neither was Roy's.
-Nick Cash
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RE: Creating a Super Simple WWW Link, Copy, Paste into Spreadsheet Program
there is a python module that reads and writes to excel files. look for that More than one, actually, and which to use depends on whether Excel files means the .xls or .xlsx format. On Windows, the most flexible solution is going to be to just use COM to control the Excel application in reading and writing the files. Outside of Windows, the best bet is usually to work with csv files instead, as Dave suggested. I've had success with the xlrd and xlwt suite of modules (http://www.python-excel.org/), using both .xls and .xlsx, on Linux. -Nick Cash -- http://mail.python.org/mailman/listinfo/python-list
RE: (any)dbm module lacks a context manager
import dbm with dbm.open(mydb, 'c') as d: ... d[hello] = world ... Traceback (most recent call last): File stdin, line 1, in module AttributeError: '_dbm.dbm' object has no attribute '__exit__' This error message is somewhat misleading... it actually means you're trying to use an object as a context manager, and it doesn't implement the context manager protocol (defined __enter__ and __exit__ methods). In this case, db.open() returns a dict -like object that is not a context manager. You'd need to refactor your code to something like: import dbm d = dbm.open(mydb, 'c') d[hello] = world d.close() You may want to wrap any actions on d with a try-except-finally so you can always close the db. If dbm objects were real context managers, they would do this for you. This does seem like a useful enhancement. It might be slightly involved to do, as the dbm module has multiple implementations depending on what libraries are available on the OS. -Nick Cash -- http://mail.python.org/mailman/listinfo/python-list
RE: Split string first data have ,
y = 'abc.p,zip.p,a,b' print y abc.p,zip.p,a,b x = what is your question?? print x I'm guessing that you want to split on ,, but want the quoted section to be a single token? Have you looked at the CSV module (http://docs.python.org/3/library/csv.html)? If my guess is wrong, or you're having difficulties with the csv module, a more specific question will help you get the answer you're looking for. -Nick Cash -- http://mail.python.org/mailman/listinfo/python-list
urllib2 FTP Weirdness
Python 2.7.3 on linux This has me fairly stumped. It looks like urllib2.urlopen(ftp://some.ftp.site/path;).read() will either immediately return '' or hang indefinitely. But response = urllib2.urlopen(ftp://some.ftp.site/path;) response.read() works fine and returns what is expected. This is only an issue with urllib2, vanilla urllib doesn't do it. The site I first noticed it on is private, but I can reproduce it with ftp://ftp2.census.gov/;. I've tested the equivalent code on Python 3.2.3 and get the same results, except that one time I got a socket error (may have been a spurious network blip, though). I'm at a loss as to how that could even work differently. My only guess is that by not having a reference to the addinfourl response object, something important is getting garbage collected or closed... that seems like a stretch, though. Is this a urllib2 bug, or am I crazy? -Nick Cash -- http://mail.python.org/mailman/listinfo/python-list
RE: Vote tallying...
I have a problem which may fit in a mysql database, but which I only have python as an alternate tool to solve... so I'd like to hear some opinions... Is there a reason you can't use an RDBMS for this? MySQL would certainly be fine, although I always recommend PostgreSQL over it. Based on the amount of data you've specified, you really don't want to be rolling your own data storage system. If you absolutely cannot install any new software, Sqllite is built into Python and would work almost as well. -- http://mail.python.org/mailman/listinfo/python-list
RE: How to get time.strptime()?
Error: AttributeError: 'module' object has no attribute '_strptime' This problem is driving me crazy. It only happens in Python 3.3.0, while on my server running 3.1.3 it behaves as expected. When I try to access time.strptime() it errors with AttributeError: 'module' object has no attribute '_strptime'. This error only occurs under mod_wsgi, when running as a one-shot webapp it behaves normally. All other functionalities of the time module are normal. I've run into this issue in the past with Python 2.6 (or maybe 2.7) and mod_python. My problem was that datetime.strptime imported _strptime at runtime, and multiple threads trying to import it at the same time broke an internal import lock. I was able to work around this by simply importing _strptime myself at server startup time. This may or may not work for you. See also: http://code.google.com/p/modwsgi/issues/detail?id=177 and http://www.mail-archive.com/python-list@python.org/msg248664.html -- http://mail.python.org/mailman/listinfo/python-list
RE: urlopen in python3
In python2, this work if something is a regular file on the system as well as a remote URL. The 2to3 script convert this to urllib.request.urlopen. But it does not work anymore if something is just a file name. My aim is to let the user specify a file on the command line and have something that works, whatever the file actually is: a regular file, an http url, etc... A file path, such as /etc/passwd, isn't properly a URL, so urllib correctly refuses to handle it. You can make it a URL by using the file:// protocol, i.e. file:///etc/passwd... which appears to work in both python2 and python3. -- http://mail.python.org/mailman/listinfo/python-list
RE: len() on mutables vs. immutables
I'm curious as to the implementation (I'd be happy to dig through the source, just don't have the time right now). I've seen various implementations across interpreters in the past (some which have been rather shocking) and I'd like to get some insight into Python (well, CPython at this point anyway). When len() is called passing an immutable built-in type (such as a string), I'd assume that the overhead in doing so is simply a function call and there are no on-call calculations done. Is that correct? I'd also assume that mutable built-in types (such as a bytearray) would cache their size internally as a side effect of mutation operations. Is that correct? If so, is it safe to assume that at least all built-in types observe this behavior, or are there some that incur an O(n) cost on every len() call? It appears that list has len() complexity of O(1) source: http://wiki.python.org/moin/TimeComplexity It may be worth mentioning that lists in Python are implemented using arrays instead of linked lists. It's reasonable to assume that other built-in collection types would be similar, though I don't see anything explicitly saying so for bytearray. -Nick Cash -- http://mail.python.org/mailman/listinfo/python-list
RE: get google scholar using python
urllib2.urlopen('http://scholar.google.co.uk/scholar?q=albert
...
urllib2.HTTPError: HTTP Error 403: Forbidden
Will you kindly explain me the way to get rid of this?
Looks like Google blocks non-browser user agents from retrieving this query.
You *could* work around it by setting the User-Agent header to something fake
that looks browser-ish, but you're almost certainly breaking Google's TOS if
you do so.
Should you really really want to, urllib2 makes it easy:
urllib2.urlopen(urllib2.Request(http://scholar.google.co.uk/scholar?q=albert+einstein%2B1905btnG=hl=enas_sdt=0%2C5as_sdtp=;,
headers={User-Agent:Mozilla/5.0 Cheater/1.0}))
-Nick Cash
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RE: Numpy combine channels
I have an array generated by audiolab of left and right stereo channels. It looks like [[1,1],[1,2],[2,3]]. I would like to combine the left and right channels to get an array [2,3,5]. Is there a numpy command to do that? You may be over-thinking this, and numpy might not be necessary. A simple solution would be just a quick list comprehension: stereo_array = [[1, 1], [1, 2], [2, 3]] mono_array = [l+r for (l, r) in stereo_array] Thanks, Nick Cash -- http://mail.python.org/mailman/listinfo/python-list
RE: vBulletin scraper -- feasible?
You may want to look into http://www.crummy.com/software/BeautifulSoup/ It's made for parsing (potentially bad) HTML, and is quite easy to use. I'd say it's quite feasible. Thanks, Nick Cash NPC International -Original Message- From: python-list-bounces+nick.cash=npcinternational@python.org [mailto:python-list-bounces+nick.cash=npcinternational@python.org] On Behalf Of Andrew D'Angelo Sent: Monday, June 25, 2012 14:10 To: python-list@python.org Subject: vBulletin scraper -- feasible? Taking a look through vBulletin's HTML, I was wondering whether it would be overly difficult to parse it into nice, manipulatible data. I'd suppose my ultimate goal would be to dynamically parse a vBulletin and feed it into a locally hosted NNTP server. -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
RE: Where to set default data - where received, or where used
This is really up to your programming style, but I'm of the opinion that defining all of the default values in one place keeps maintenance easier. Of course, if it's done differently elsewhere in your code base, I would aim for consistency instead. Thanks, Nick Cash -Original Message- From: python-list-bounces+nick.cash=npcinternational@python.org [mailto:python-list-bounces+nick.cash=npcinternational@python.org] On Behalf Of Dennis Carachiola Sent: Monday, June 11, 2012 13:38 To: python-list@python.org Subject: Where to set default data - where received, or where used I'm programming a project which will use a file to save parameters needed by the program. There are already two previous file formats, each of which can only be run by the version of the program which created them. I'm trying to avoid that problem in the future. To do that, I intend to use a dictionary, and default data. I believe that most new versions will add parameters. Each version of the program will have reasonable default values for each key in the dictionary handled by that version. If an older file is used, the data values in that file replace the keys that exist. The program then can operate on the values supplied by the older data file and the default values. Conversely, if a newer file is used, the data in the file replaces the keys in the dictionary. The program then simply doesn't access the newer data values. I'm hoping that this will make the file backward and forward compatible. Here's my question. I could do this by creating the dictionary with the default values, then read the file into it. Or I could use a 'get' with default values at the location in the program where those values are used. From what I can see, creating the dictionary with default values puts everything in one place. While, supplying the default values at the place where they're used places the default values nearest the place where actually used. I can't decide on one way over the other. Can anyone give me some ideas if one is a preferred method, or other criteria I've overlooked? Thanks, Den -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
