Re: Quick Question About Setting Up Pytz
On Sunday, October 19, 2014 8:25:53 AM UTC+5:30, Ben Finney wrote: > Chris Angelico writes: > > Try learning Python itself, rather than playing around with extension > > packages like pytz. > To be fair, "You need to install 'pytz' to work correctly with date and > time values" is correct advice. If the OP doesn't install it early, then > works with timestamps, problems are inevitable -- at which point "oh, you > needed to do that first" will be inevitable. It's lose-lose. Yes > It's a sad fact that MS Windows has completely useless timezone support, > and this "install a third-party package" hurdle is a cost that is paid > by all people trying to set up Python on MS Windows. About MS-lacunae Ive nothing to say [Just head over to a debian list like users or vote or.. and witness the riot going on over systemd... Hard to believe all's right in Linux-land] As for this OP and similar problems -- yes python is in a peculiar position. Because of 'batteries included' beginners can do powerful stuff. However sometimes the batteries need to be supplemented. And then there's a problem -- its not clear whether - the beginner is having classic noob problems. Expert just needs to tweak a command a bit and he's sailing - the beginner is in somewhat uncharted (research-needed) land -- charting the route between mutually complementary AND competing setup tools I believe python must be some sort of record setter in this that o pip is a replacement for easy_install o you install pip with easy_install !! -- https://mail.python.org/mailman/listinfo/python-list
Re: Quick Question About Setting Up Pytz
On Sun, Oct 19, 2014 at 1:54 PM, Ben Finney wrote: > Chris Angelico writes: > >> Try learning Python itself, rather than playing around with extension >> packages like pytz. > > To be fair, “You need to install ‘pytz’ to work correctly with date and > time values” is correct advice. If the OP doesn't install it early, then > works with timestamps, problems are inevitable — at which point “oh, you > needed to do that first” will be inevitable. It's lose–lose. > > It's a sad fact that MS Windows has completely useless timezone support, > and this “install a third-party package” hurdle is a cost that is paid > by all people trying to set up Python on MS Windows. That's a rough business to be in... I mean... that's unfortunate. However, I'd still advise anyone to learn the language itself first, even if that means a rule like "avoid working with international or historical time". There are plenty of other things Python can do, even just with a basic Windows installation. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: Quick Question About Setting Up Pytz
Chris Angelico writes: > Try learning Python itself, rather than playing around with extension > packages like pytz. To be fair, “You need to install ‘pytz’ to work correctly with date and time values” is correct advice. If the OP doesn't install it early, then works with timestamps, problems are inevitable — at which point “oh, you needed to do that first” will be inevitable. It's lose–lose. It's a sad fact that MS Windows has completely useless timezone support, and this “install a third-party package” hurdle is a cost that is paid by all people trying to set up Python on MS Windows. -- \ “Nothing is more sacred than the facts.” —Sam Harris, _The End | `\ of Faith_, 2004 | _o__) | Ben Finney -- https://mail.python.org/mailman/listinfo/python-list
Re: Quick Question About Setting Up Pytz
ryguy7272 writes: > So, when I run it, the setup.py text file opens. Nothing runs; nothing > installs. You have somehow (either manually, or by answering a question to some program) associated the ‘.py’ suffix with “Open this file in my text editor”. That's fine, but it means that if you don't want to edit the file but instead want to execute it, you need to *explicitly* start Python: python /whatever/path/to/setup.py install > This makes no sense whatsoever. This is an issue with your operating system, so I would hope you can learn more about that to distinguish what is causing your frustration :-) -- \ “I got an answering machine for my phone. Now when someone | `\ calls me up and I'm not home, they get a recording of a busy | _o__) signal.” —Steven Wright | Ben Finney -- https://mail.python.org/mailman/listinfo/python-list
Re: Quick Question About Setting Up Pytz
On Sun, Oct 19, 2014 at 1:44 PM, ryguy7272 wrote: > I'll probably give it until the end of the year, and start learning Chinese. > There's other things I want to do with my time. I know 10 programming > languages. I thought it would be fun to learn Python, but after 2 months, I > still can't run a single line of code. This language makes no sense > whatsoever, and it never does anything that you tell it to do. > Try learning Python itself, rather than playing around with extension packages like pytz. You're having trouble installing add-ons - that's like saying "Computers are total rubbish, I bought this fancy new ISA card and I can't make it work!". Start with what you have, and worry about the extra complexities later. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: Quick Question About Setting Up Pytz
On Saturday, October 18, 2014 3:55:02 PM UTC-4, ryguy7272 wrote: > I downloaded PYTZ and put it here. > > C:\Python27\pytz > > > > Now, in the cmd window, I typed this: > > C:\Python27\pytz\setup.py > > > > A text file opens and nothing else happens. I thought it was supposed to > install the PYTZ library. > > > > What am I doing wrong? Thanks Mark. That makes sense. I moved the folder to the desktop and I just tried that: C:\Users\Ryan\Desktop\pytz>setup.py install So, when I run it, the setup.py text file opens. Nothing runs; nothing installs. This makes no sense whatsoever. If I tell a program to install something, it should install something. It should not pop open a text file. I'll probably give it until the end of the year, and start learning Chinese. There's other things I want to do with my time. I know 10 programming languages. I thought it would be fun to learn Python, but after 2 months, I still can't run a single line of code. This language makes no sense whatsoever, and it never does anything that you tell it to do. -- https://mail.python.org/mailman/listinfo/python-list
Re: Flush stdin
On Sat, Oct 18, 2014 at 6:34 PM, Dan Stromberg wrote: >> Once the "nc" process actually write()s the data to its standard >> output (i.e. desriptor 1, not the "stdout" FILE*) > I'm not sure why you're excluding stdout, but even if nc is using > filedes 1 instead of FILE * stdout, isn't it kind of irrelevant? On further reflection, isn't it stdio that does the varied buffering, and filedes 1 that's always unbuffered? IOW, the OP might wish nc was using 1, but it probably can't be given what they're seeing. -- https://mail.python.org/mailman/listinfo/python-list
Re: Flush stdin
On Sat, Oct 18, 2014 at 6:11 PM, Nobody wrote: > On Sat, 18 Oct 2014 12:32:07 -0500, Tim Chase wrote: > >> On 2014-10-18 17:55, Nobody wrote: >>> On Fri, 17 Oct 2014 12:38:54 +0100, Empty Account wrote: >>> >>> > I am using netcat to listen to a port and python to read stdin and >>> > print to the console. >>> > >>> > nc -l 2003 | python print_metrics.py >>> > >>> > sys.stdin.flush() doesn’t seem to flush stdin, >>> >>> You can't "flush" an input stream. >> >> You can't flush it, but you can make it unbuffered. You can either force >> python to use unbuffered stdio: > > [snipped] > > None of this helps in any way, as it's not the behaviour of the Python > script which is causing the problem, but that "nc" is (probably) buffering > its output, so the data isn't passed to the OS (let alone to the Python > script) in a timely manner. Agreed. > Once the "nc" process actually write()s the data to its standard > output (i.e. desriptor 1, not the "stdout" FILE*) I'm not sure why you're excluding stdout, but even if nc is using filedes 1 instead of FILE * stdout, isn't it kind of irrelevant? > it will be available to > the Python script immediately thereafter without requiring any low-level > tweaks. Which, on a pipe, generally means either the buffer filled and needed to be passed along to make room, or the process exited. I'd probably rewrite just enough nc in Python to make it so you don't need to depend on a pipe (example: http://stromberg.dnsalias.org/~strombrg/pnetcat.html), but if you're on *ix you could try http://ftp.sunet.se/pub/usenet/ftp.uu.net/comp.sources.unix/volume23/pty/ in an effort to persuade nc to think that it's on a tty and hence should output line buffered data instead of block buffered - despite being on a pipe in reality. HTH. -- https://mail.python.org/mailman/listinfo/python-list
Re: Flush stdin
On Fri, Oct 17, 2014 at 10:38 PM, Empty Account wrote: > I am using netcat to listen to a port and python to read stdin and print to > the console. > > nc -l 2003 | python print_metrics.py After lengthy discussion about what it means to flush stdin, I think it's high time someone asked the question: Why not skip nc altogether, and have your Python program do its own socket work? Then you don't have to worry about stream flushing at all. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: Flush stdin
On Sat, 18 Oct 2014 12:32:07 -0500, Tim Chase wrote: > On 2014-10-18 17:55, Nobody wrote: >> On Fri, 17 Oct 2014 12:38:54 +0100, Empty Account wrote: >> >> > I am using netcat to listen to a port and python to read stdin and >> > print to the console. >> > >> > nc -l 2003 | python print_metrics.py >> > >> > sys.stdin.flush() doesn’t seem to flush stdin, >> >> You can't "flush" an input stream. > > You can't flush it, but you can make it unbuffered. You can either force > python to use unbuffered stdio: [snipped] None of this helps in any way, as it's not the behaviour of the Python script which is causing the problem, but that "nc" is (probably) buffering its output, so the data isn't passed to the OS (let alone to the Python script) in a timely manner. Once the "nc" process actually write()s the data to its standard output (i.e. desriptor 1, not the "stdout" FILE*), it will be available to the Python script immediately thereafter without requiring any low-level tweaks. -- https://mail.python.org/mailman/listinfo/python-list
Re: Flush stdin
On 10/18/2014 5:01 PM, Cameron Simpson wrote: On 18Oct2014 17:55, Nobody wrote: On Fri, 17 Oct 2014 12:38:54 +0100, Empty Account wrote: I am using netcat to listen to a port and python to read stdin and print to the console. nc -l 2003 | python print_metrics.py sys.stdin.flush() doesn’t seem to flush stdin, You can't "flush" an input stream. Sure you can. You are collectively confusing three different meaning of 'flush'. Python and its docs are the best authority on what python can and cannot do. One can "call .flush() on an imput stream" (meaning 1). >>> import sys >>> sys.stdin.flush() >>> However, one cannot "empty the steam buffer by calling .flush()" (meaning 2). " class IOBase ... flush() Flush the write buffers of the stream if applicable. This does nothing for read-only and non-blocking streams." Most streams are read through an API which buffers. That buffer can be discarded. But one can "empty and discard the buffer" (meaning 3) with stream.read() And, of course, an 'input stream' 'down here' is an 'output stream' 'up there, where ever' and one can 'flush' pending output into the stream so that it can be read here. -- Terry Jan Reedy -- https://mail.python.org/mailman/listinfo/python-list
Re: Flush stdin
On 18Oct2014 17:55, Nobody wrote: On Fri, 17 Oct 2014 12:38:54 +0100, Empty Account wrote: I am using netcat to listen to a port and python to read stdin and print to the console. nc -l 2003 | python print_metrics.py sys.stdin.flush() doesn’t seem to flush stdin, You can't "flush" an input stream. Sure you can. Most streams are read through an API which buffers. That buffer can be discarded. I'm not sure it is what the OP needs, but it is not a nonsensical idea. Cheers, Cameron Simpson I've seen things you people wouldn't believe. Attack ships on fire off the shoulder of Orion. I've watched C-beams glitter in the dark near the Tannhauser Gate. All these memories will be lost in time, like tears in rain. - Roy Baty, _Blade Runner_ -- https://mail.python.org/mailman/listinfo/python-list
Re: Quick Question About Setting Up Pytz
On 18/10/2014 20:54, ryguy7272 wrote: I downloaded PYTZ and put it here. C:\Python27\pytz Now, in the cmd window, I typed this: C:\Python27\pytz\setup.py A text file opens and nothing else happens. I thought it was supposed to install the PYTZ library. What am I doing wrong? You will end up confusing yourself very quickly if you insist on placing files in c:\Python27. Please put them anywhere except that spot, say in downloads or on the desktop. Let's assume your desktop is here c:\Users\ryguy7272\Desktop. Open a cmd window then cd c:\Users\ryguy7272\Desktop setup.py install should work if and only if you have the file types and file associations correctly set, please see https://docs.python.org/2/using/windows.html#executing-scripts Better still take the hard work out of it by getting pip by following the instructions here http://pip.readthedocs.org/en/latest/installing.html -- My fellow Pythonistas, ask not what our language can do for you, ask what you can do for our language. Mark Lawrence -- https://mail.python.org/mailman/listinfo/python-list
Question about PANDAS
I'm trying to install Pandas. I went to this link. https://pypi.python.org/pypi/pandas/0.14.1/#downloads I downloaded this: pandas-0.14.1.win32-py2.7.exe (md5) I have Python27 installed. So, I run the executable and re-run my Python script and I get the same error as before. Traceback (most recent call last): File "C:/Python27/stock_data.py", line 3, in import pandas as pd ImportError: No module named pandas I thought I just installed it! Isn't that what the executable is for? It seems like 100% of my errors are with uninstalled libraries. I don't understand why there are so, so, so many dependencies running Python. Also, I don't understand why something isn't installed, right after I just installed it. Can someone please explain the logic to me? Thanks. -- https://mail.python.org/mailman/listinfo/python-list
Re: Quick Question About Setting Up Pytz
On Sat, Oct 18, 2014 at 3:54 PM, ryguy7272 wrote: > I downloaded PYTZ and put it here. > C:\Python27\pytz > > Now, in the cmd window, I typed this: > C:\Python27\pytz\setup.py > > A text file opens and nothing else happens. I thought it was supposed to > install the PYTZ library. > > What am I doing wrong? > -- > https://mail.python.org/mailman/listinfo/python-list have you tried: python c:\Python27/pytz/setup.py -- Joel Goldstick http://joelgoldstick.com -- https://mail.python.org/mailman/listinfo/python-list
Quick Question About Setting Up Pytz
I downloaded PYTZ and put it here. C:\Python27\pytz Now, in the cmd window, I typed this: C:\Python27\pytz\setup.py A text file opens and nothing else happens. I thought it was supposed to install the PYTZ library. What am I doing wrong? -- https://mail.python.org/mailman/listinfo/python-list
Re: Flush stdin
On 2014-10-18 17:55, Nobody wrote: On Fri, 17 Oct 2014 12:38:54 +0100, Empty Account wrote: I am using netcat to listen to a port and python to read stdin and print to the console. nc -l 2003 | python print_metrics.py sys.stdin.flush() doesn’t seem to flush stdin, You can't "flush" an input stream. [snip] Flushing an input stream means (or could mean) discarding any data that's currently in the buffer. -- https://mail.python.org/mailman/listinfo/python-list
Re: Flush stdin
On 2014-10-18 17:55, Nobody wrote: > On Fri, 17 Oct 2014 12:38:54 +0100, Empty Account wrote: > > > I am using netcat to listen to a port and python to read stdin > > and print to the console. > > > > nc -l 2003 | python print_metrics.py > > > > sys.stdin.flush() doesn’t seem to flush stdin, > > You can't "flush" an input stream. You can't flush it, but you can make it unbuffered. You can either force python to use unbuffered stdio: python -u myfile.py or you can get an unbuffered handle to the file import os, sys buffer_size = 1 new_stdin = os.fdopen(sys.stdin.fileno(), 'r', buffer_size) for c in new_stdin: do_something(c) though based on my reading, the first method works with both Py2 and Py3k while the second method doesn't reliably work in Py3k. -tkc -- https://mail.python.org/mailman/listinfo/python-list
Re: Flush stdin
On Fri, 17 Oct 2014 12:38:54 +0100, Empty Account wrote: > I am using netcat to listen to a port and python to read stdin and print > to the console. > > nc -l 2003 | python print_metrics.py > > sys.stdin.flush() doesn’t seem to flush stdin, You can't "flush" an input stream. > so I am using the termios module. > I am receiving this exception > termios.error: (25, 'Inappropriate ioctl for device') termios only works on terminals, not pipes. It's a safe bet that your problem is that "nc" isn't flushing its stdout after each line (this is the default behaviour for stdio streams which don't correspond to a terminal). Check whether "nc" has a flag to line-buffer its output. If it doesn't, the simplest solution is probably to write a Python script which creates a pseudo-tty (using the "pty" module) and executes "nc" with its stdout associated with the pty. -- https://mail.python.org/mailman/listinfo/python-list
Re: your mail
Alain Ketterlin wrote:
> Terry Reedy writes:
>
>> On 10/17/2014 6:43 AM, Cameron Simpson wrote:
>>> On 17Oct2014 11:45, Dhananjay wrote:
>>
2.1576318858 -1.8651195165 4.2333428278
...
(total of 200 lines)
Columns 1,2,3 corresponds to x,y,z axis data points.
>>
>>>for line in open('flooding-psiphi.dat','r'):
>>>line = line.split()
>>>xs.append(float(line[0]))
>>>ys.append(float(line[1]))
>>>zs.append(float(line[2]))
>>
>> A further refinement:
>>for line in open('flooding-psiphi.dat','r'):
>>x, y, z = map(float, line.split())
>>xs.append(x)
>>ys.append(y)
>>zs.append(z)
>
> Or even:
>
> xs,ys,zs = zip(*[ map(float,line.split())
> for line in open('flooding-psiphi.dat','r') ])
>
> You get tuples, though. Use map(list,zip(...)) if you need lists. Easy
> to update when you move to 4D data...
Given the context (the script uses numpy) there is another option:
xs, ys, zs = numpy.loadtxt('flooding-psiphi.dat').T
There may also be a way to feed the array to matplotlib without breaking it
into the three columns...
--
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Re: pyserial on freebsd 10.10 i386 [SOLVED]
The port parameter of serial.Serial should be /dev/ttyu0 instead of COM1, and /dev/ttyu1 instead of COM2. Strangely, pyserial will accept the number 0, but then it tries to open a device that exists on Linux only... Anyway, problem solved. -- https://mail.python.org/mailman/listinfo/python-list
Re: your mail
Terry Reedy writes:
> On 10/17/2014 6:43 AM, Cameron Simpson wrote:
>> On 17Oct2014 11:45, Dhananjay wrote:
>
>>> 2.1576318858 -1.8651195165 4.2333428278
>>> ...
>>> (total of 200 lines)
>>>
>>> Columns 1,2,3 corresponds to x,y,z axis data points.
>
>>for line in open('flooding-psiphi.dat','r'):
>>line = line.split()
>>xs.append(float(line[0]))
>>ys.append(float(line[1]))
>>zs.append(float(line[2]))
>
> A further refinement:
>for line in open('flooding-psiphi.dat','r'):
>x, y, z = map(float, line.split())
>xs.append(x)
>ys.append(y)
>zs.append(z)
Or even:
xs,ys,zs = zip(*[ map(float,line.split())
for line in open('flooding-psiphi.dat','r') ])
You get tuples, though. Use map(list,zip(...)) if you need lists. Easy
to update when you move to 4D data...
-- Alain.
--
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Re: Is there an easy way to control indents in Python
Simon Kennedy wrote:
> On Wednesday, 15 October 2014 20:31:15 UTC+1, Ian wrote:
>> I agree. I very rarely use blank lines inside functions. As I see it,
>> if you feel you need a blank line for separation within a function,
>> that's an indication your function is overly complex and should be
>> broken up.
>
> Whereas I feel that if I wanted to write code which looked like that I'd
> have learnt/learned Perl ;-)
I'm curious what aspect of idiomatic Perl code you are referring to. When
people talk about Perl code dismissively, I normally think of three things:
- excessively long one-liners;
- excessive use of symbols and sigils ("line noise");
- "More Than One [Thousand] Ways To Do It"
Are you suggesting that Perl functions tend to be too small? What do you
consider "too small"?
--
Steven
--
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pyserial on freebsd 10.10 i386
I'm trying to open a serial port with pyserial on a Compaq Deskpro EN machine. Operating system is FreeBSD 10.10 RELEASE, i386. root@merleg:~ # kldload scc root@merleg:~ # python2.7 -m serial.tools.list_ports no ports found root@merleg:~ # whoami root Here are all the devices: root@merleg:~ # ls /dev acpicttyklogstdin ttyva ad0 cuau0 kmemstdout ttyvb ad0p1 cuau0.init log sysmousettyvc ad0p2 cuau0.lock lpt0ttyu0 ttyvd ad0p3 cuau1 lpt0.ctlttyu0.init ttyve ada0cuau1.init mdctl ttyu0.lock ttyvf ada0p1 cuau1.lock mem ttyu1 ufssuspend ada0p2 devctl midistatttyu1.init ugen0.1 ada0p3 devstat mixer0 ttyu1.lock ugen0.2 agpgart fd nfslock ttyv0 uhid0 apm fd0 nullttyv1 ukbd0 apmctl fidopass0 ttyv2 urandom atkbd0 geom.ctlpass1 ttyv3 usb audit gptid pci ttyv4 usbctl bpf io ppi0ttyv5 xpt0 bpf0kbd0pts ttyv6 zero cd0 kbd1random ttyv7 console kbd2sndstat ttyv8 consolectl kbdmux0 stderr ttyv9 And here is what I see in dmesg: root@merleg:~ # dmesg | grep uart uart0: <16550 or compatible> port 0x3f8-0x3ff irq 4 flags 0x10 on acpi0 uart1: <16550 or compatible> port 0x2f8-0x2ff irq 3 on acpi0 Obviously the question is: how do I open the COM port from pyserial on this machine? -- https://mail.python.org/mailman/listinfo/python-list
Re: Sqlite3 help
Am 14.10.2014 15:36, schrieb Chuck:
I am building a simple podcast program where I download all the data from a
feed with feedparser and store the data in sqlite3. I am spanking new to
sqlite and database programming. Should I create the database in the __init__
method of my class, or is that a bad idea. I haven't done any designing that
included databases.
Thanks!
Chuck
When I first answered this question, I sent the answer erroneously to
the OP and not to the list. So here it is again.
On Tue, Oct 14, 2014 at 1:19 PM, Sibylle Koczian wrote:
>
> As I don't know anything at all about podcasts and feeds, I'll just
> answer your question about creating the database in the __init__
> method of your class:
>
> That would destroy the existing database and create a new one without
> any data. If you don't want to keep data from former runs of your
> application, this wouldn't be necessary, because you could just
> delete the data and keep the database. But most probably you want to
> keep your data and add to it. In this case, you certainly don't want
> to create a new database.
>
> The __init__ method of your class might be the right place to open
> the database, though.
>
> You know that the documentation for the sqlite3 module is part of the
> Python documentation? It contains links to the SQLite web page and to
> a website with beginner information about SQL itself. So that should
> help to get you started.
Am 15.10.2014 18:51, schrieb Chuck Johnson:
>
> I was thinking that I could fix that by using ' ' ' CREATE TABLE IF
> NOT EXISTS ' ' ' Should I make the sqlite3.connect() command a
> global variable? I am not sure about how to design this properly.
>
That should work. I wouldn't make the connection a global variable. Use
it as a parameter for every function that needs it. Roughly like this:
import sqlite3
# other imports as needed
def one_of_my_functions(myconn, my_other_parameters):
mycurs = myconn.cursor()
try:
# do things with mycurs and my_other_parameters
finally:
mycurs.close()
myconn.commit()
# more of the same ...
def main():
conn = sqlite3.connect('path/to/my/database')
try:
one_of_my_functions(conn, params)
# more of the same
finally:
conn.close()
if __name__ == "__main__":
main()
Or, if your program gets bigger, you might start and stop a connection
inside a function instead of keeping one connection open for all of the
application.
HTH
Sibylle
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Re: Extract Indices of Numpy Array Based on Given Bit Information
On Sat, Oct 18, 2014 at 4:10 PM, Chris Angelico wrote: > On Sat, Oct 18, 2014 at 6:02 PM, Artur Bercik wrote: > > So, the Bit No. 2-5 for the following case is '1101', right? > > > > 1073741877: 1110101 > > > > If my required bit combination for Bit No. 2-5 is '1011', then the above > > number (1073741877) is not chosen, right?? > > > > Look forward to know your confirmation. > > (Side point: Please don't top-post. The convention on this mailing > list, and most other technical mailing lists, is what's sometimes > called "interleaved style"; you trim the quoted text to what's needed > for context, and put your text underneath what you're referring to. > See https://en.wikipedia.org/wiki/Posting_style#Interleaved_style for > more info.) > > >>> 1073741877&60 > 52 > >>> bin(52) > '0b110100' > > Everything I've written with the triple-angle-bracket marker can be > typed in at the Python prompt, and you'll see exactly what it does. In > this case, you can see that you're absolutely right: 1073741877 has > 1101 in those positions, so if you're looking for 1011, it won't > match: > > >>> 0b101100 > 44 > > However, 1073741869 would: > > >>> 1073741869&60 > 44 > > The way to test would be something like this: > > >>> (1073741877 & 0b00) == 0b101100 > False > >>> (1073741869 & 0b00) == 0b101100 > True > Thank you very much Chris Angelico, I have come to know it. > > ChrisA > -- > https://mail.python.org/mailman/listinfo/python-list > -- https://mail.python.org/mailman/listinfo/python-list
Re: Extract Indices of Numpy Array Based on Given Bit Information
So, the Bit No. 2-5 for the following case is '1101', right? 1073741877: 1110101 If my required bit combination for Bit No. 2-5 is '1011', then the above number (1073741877) is not chosen, right?? Look forward to know your confirmation. On Sat, Oct 18, 2014 at 3:50 PM, Chris Angelico wrote: > On Sat, Oct 18, 2014 at 5:42 PM, Artur Bercik wrote: > > I got some sense, but could not imagine if required Bit No. 2–5, and Bit > > Combination . > > > > I hope example with the new case would make me more sense. > > > > Just write the number in binary, with the bits you're interested in > set to 1, and everything else 0: > > ... 876543210 > ... 00000 > > >>> 0b00000 > 60 > >>> 1073741877 & 0b00000 > 52 > > So this number does _not_ have all zeroes there. If it did, the result > would be zero. To look for some other pattern, just do the same thing > - suppose we want to find numbers where it's 1001, we just look for > the result to be 0b000100100, or 36. > > ChrisA > -- > https://mail.python.org/mailman/listinfo/python-list > -- https://mail.python.org/mailman/listinfo/python-list
Re: Extract Indices of Numpy Array Based on Given Bit Information
Thanks Chris Angelico for your nice answer. I got some sense, but could not imagine if required Bit No. 2–5, and Bit Combination . I hope example with the new case would make me more sense. Artur On Sat, Oct 18, 2014 at 3:24 PM, Chris Angelico wrote: > On Sat, Oct 18, 2014 at 4:58 PM, Artur Bercik wrote: > > I want to get the index of my data where the following occurs: > > > > Bit No. 0–1 > > Bit Combination: 00 > > So, what you want to do is look at each number in binary, and find the > ones that have two zeroes in the last two places? > 1073741824: 100 > 1073741877: 1110101 > > The easiest way to do this is with simple bitwise operations: > > >>> 1073741824 & 3 > 0 > >>> 1073741877 & 3 > 1 > > 3 is 0011 in binary, so a bitwise AND with that will tell > you about just the last two bits. The result will be an integer - 0, > 1, 2, or 3, representing 00, 01, 10, or 11 for those last two bits. So > all you have to do is AND each number with 3, and when the result is > 0, that's what you want. > > Does that make sense? > > ChrisA > -- > https://mail.python.org/mailman/listinfo/python-list > -- https://mail.python.org/mailman/listinfo/python-list
Re: Extract Indices of Numpy Array Based on Given Bit Information
On Sat, Oct 18, 2014 at 6:21 PM, Artur Bercik wrote: > Thank you very much Chris Angelico, I have come to know it. > You're most welcome. And thank you for taking heed of the request to not top-post. :) Hang around, you never know what weird and wonderful things you'll learn! -- https://mail.python.org/mailman/listinfo/python-list
Re: Extract Indices of Numpy Array Based on Given Bit Information
On Sat, Oct 18, 2014 at 6:02 PM, Artur Bercik wrote: > So, the Bit No. 2-5 for the following case is '1101', right? > > 1073741877: 1110101 > > If my required bit combination for Bit No. 2-5 is '1011', then the above > number (1073741877) is not chosen, right?? > > Look forward to know your confirmation. (Side point: Please don't top-post. The convention on this mailing list, and most other technical mailing lists, is what's sometimes called "interleaved style"; you trim the quoted text to what's needed for context, and put your text underneath what you're referring to. See https://en.wikipedia.org/wiki/Posting_style#Interleaved_style for more info.) >>> 1073741877&60 52 >>> bin(52) '0b110100' Everything I've written with the triple-angle-bracket marker can be typed in at the Python prompt, and you'll see exactly what it does. In this case, you can see that you're absolutely right: 1073741877 has 1101 in those positions, so if you're looking for 1011, it won't match: >>> 0b101100 44 However, 1073741869 would: >>> 1073741869&60 44 The way to test would be something like this: >>> (1073741877 & 0b00) == 0b101100 False >>> (1073741869 & 0b00) == 0b101100 True ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: Flush stdin
On 17Oct2014 12:38, Empty Account wrote: I am using netcat to listen to a port and python to read stdin and print to the console. nc -l 2003 | python print_metrics.py sys.stdin.flush() doesn’t seem to flush stdin, so I am using the termios module. You're aware that a stdio flush and a termios flush operate on two totally unrelated buffers? while True: input = sys.stdin.readline() # do some parsing … sys.stdout.write(parsed_data) time.sleep(3) termios.tcflush(sys.stdin, termios.TCIOFLUSH) I am receiving this exception termios.error: (25, 'Inappropriate ioctl for device') That is because stdin is attached to the pipe from netcat. A pipe is not a terminal. I will be using this script on Unix based systems and I wondered what approach I could use to flush stdin? Like Chris, I think you need to explain why you even want to flush stdin. There's probably something better you can do. Cheers, Cameron Simpson I strongly suspect so. Practically everyone on sci.physics has a theory that is far superior to special relativity, general relativity, quantum mechanics *and* the standard model. Around here, it's only a small clique of arrogant young members of the physics establishment who fail to recognize these revolutionary theories. I'd explain why, but I have to go finish designing my faster-than-light vacuum energy perpetual motion telekinetic aether-powered time machine.- John Baez -- https://mail.python.org/mailman/listinfo/python-list
Re: [OT] spelling colour / color was Re: Toggle
duncan smith writes: > [...] It was the "top / bottom of the [TV] programme" that I didn't > immediately get, because I was thinking of a timeline running left > to right (perhaps rather than the script used by the presenters). is it just me that thinks of a timeline running from the wall behind the tv set into my dinette? -- https://mail.python.org/mailman/listinfo/python-list
