Hello everyone,
How can I get the file name and line number in python script.
Exactly the file information we get from an exception traceback. In this case without raising an exception.
This whole topic is way out of my depth, so forgive my imprecise question, but I have two computers both connected to one LAN.
What I want is to be able to communicate one string between the two, by running a python script on the first (the host) where the string will originate, and a second on the client computer to retrieve the string.
What is the most efficient way for an inexperienced programmer like me to achieve this?
Since input and raw_input() stop the program from running anymore, I want to use a subprocess to run this program...
while True: print raw_input()
and get its output.
This is what I have as my reading program:
import subprocess
process = subprocess.Popen('python subinput.py', stdout=subprocess.PIPE, stderr=subprocess.PIPE)
while True:
output=process.stdout.read(12)
if output=='' and process.poll()!=None:
break
if output!='':
sys.stdout.write(output)
sys.stdout.flush()
When I run this, the subprocess exits almost as fast as it started. How can I fix this?
I have a text document that contains a list of numbers and I want to convert it to a list. Right now I can only get the entire list in the 0th entry of the list, but I want each number to be an element of a list. Does anyone know of an easy way to do this in Python?
1000
2000
3000
4000
to
['1000','2000','3000','4000']
Format is like:
CHINA;2002-06-25 00:00:00.000;5,60
CHINA;2002-06-26 00:00:00.000;5,32
CHINA;2002-06-27 00:00:00.000;5,31
and I try to use Python's CSV tools to parse it but cannot understand the paragraph, source:
And while the module doesn’t directly support parsing strings, it can easily be done:
import csv
for row in csv.reader(['one,two,three']):
print row
Could someone clarify the line ['one,two,three']? How would you use it with format A;B;C?
I was working with Python with a Linux terminal screen. When I typed:
help(somefunction)
It printed the appropriate output, but then my screen was stuck, and at the bottom of the terminal was "(end)".
How do I get unstuck? Thanks in advance.
The greenlet package is used by gevent and eventlet for asynchronous IO. It is written as a C-extension and therefore doesn't work with Jython or IronPython. If performance is of no concern, what is the easiest approach to implementing the greenlet API in pure Python.
A simple example:
def test1():
print 12
gr2.switch()
print 34
def test2():
print 56
gr1.switch()
print 78
gr1 = greenlet(test1)
gr2 = greenlet(test2)
gr1.switch()
Should print 12, 56, 34 (and not 78).
I am running a multithreaded application(Python2.7.3) in a Intel(R) Core(TM)2 Duo CPU E7500 @ 2.93GHz. I thought it would be using only one core but using the "top" command I see that the python processes are constantly changing the core no. Enabling "SHOW THREADS" in the top command shows diffrent thread processes working on different cores.
Can anyone please explain this? It is bothering me as I know from theory that multithreading is executed on a single core.
I downloaded a webpage in my python script.
In most cases, this works fine.
However, this one had a response header: GZIP encoding, and when I tried to print the source code of this web page, it had all symbols in my putty.
How do decode this to regular text?
I am creating an application that lets users login using Google, Facebook and the website's native login. The site is being built in Python / Django.
What would be the best way to handle login, session management and user authentication?
I do not want to use the in-built Django user management. I am using Django very sparingly(URLs, templates)
I have a few questions about python
I've seen many pages like these on Google
http://mail.google.com/support/bin/answer.py?answer=6583
https://www.google.com/adsense/support/bin/topic.py?topic=13488
...that have .py extensions. 1: Are pages like these built on pure python code, but printing out html like print "<div etc..." or like the typical asp,jsp,php type of pages with html pages and embedded python code like:
<html>
<% some python code %>
</html>
2: What is python mainly used for making? windows apps or web or .. ?
3: Are ruby and perl also similar to python?
Hi
I am trying to perform a 2d convolution in python using numpy
I have a 2d array as follows with kernel H_r for the rows and H_c for the columns
data = np.zeros((nr, nc), dtype=np.float32)
#fill array with some data here then convolve
for r in range(nr):
data[r,:] = np.convolve(data[r,:], H_r, 'same')
for c in range(nc):
data[:,c] = np.convolve(data[:,c], H_c, 'same')
It does not produce the output that I was expecting, does this code look OK
Thanks
how can I use wild cars like '*' when getting a list of files inside a directory in Python? for example, I want something like:
os.listdir('foo/*bar*/*.txt')
which would return a list of all the files ending in .txt in directories that have bar in their name inside of the foo parent directory.
how can I do this?
thanks.
Hi there,
I have a piece of text that gets handed to me like:
here is line one\n\nhere is line two\n\nhere is line three
What I would like to do is break this string up into three separate variables.
I'm not quite sure how one would go about accomplishing this in python.
Thanks for any help,
jml
What's the best way of getting the last item from an iterator in Python 2.6? For example, say
my_iter = iter(range(5))
What is the shortest-code / cleanest way of getting 4 from my_iter?
I could do this, but it doesn't seem very efficient:
[x for x in my_iter][-1]
Hi,
I'm use nosetests to run some tests. However, after the tests have finished running, the nosetests process just sits there, and will not exit. Is there anyway to diagnose this? Does Python have a facility similar to sending Java a kill -QUIT which will print a stack trace?
So the setup is a slew of proprietary server/client Python applications running on one Linux box (the server) and a set of Windows 7 workstations (the clients). Everything is running smoothly until any of the proprietary Python packages needs updating.
For now I am using distutils eggs which are very easily updated with easy_install, but it is still a manual process which quickly becomes tedious as the number of applications and client workstations grow.
The ideal setup IMHO is to have the Python packages on the server so when a client application is launched on a workstation the client application can check to see whether its current Python packages are up-to-date. If not, the client application should download the newer Python package from the server, install it, and then launch as per normal.
Does this sounds familiar to anyone? I have tried to find alternatives myself, but as far as I can see there is no Python module offering this functionality. Does anyone have any home made solutions for this?
wow i thought i knew python untill tonight.. what is the correct way to do something like this.. heres my code
a = ["one", "two", "three"]
b = a #here i want a complete copy that when b is changed, has absolutely no effect on a
b.append["four"]
print a #a now has "four" in it..
so basically i want to know, instead of the b = a step, how would i correctly make a copy of a list or dictionary so that when b is changed a does not change along with it.. thanks guys
I'm looking for a way in python to find out which type of file system is being used for a given path. I'm wanting to do this in a cross platform way. On linux I could just grab the output of df -T but that won't work on OSX or windows.
In Javascript I can do this:
function A(x) { return x || 3; }
This returns 3 if x is a "non-truthful" value like 0, null, false, and it returns x otherwise. This is useful for empty arguments, e.g. I can do A() and it will evaluate as 3.
Does Python have an equivalent? I guess I could make one out of the ternary operator a if b else c but was wondering what people use for this.
Hi,
Fastest way to uniqify a list in Python without preserving order? I saw many complicated solutions on Internet - could they be faster then simply:
list(set([a,b,c,a]))
?
Is there a general convention about exposing members in Python classes? I know that this is a case of "it depends", but maybe there is a rule of thumb.
Private member:
class Node:
def __init__(self):
self.__childs = []
def add_childs(self, *args):
self.__childs += args
node = Node()
node.add_childs("one", "two")
Public member:
class Node2:
def __init__(self):
self.childs = []
node2 = Node2()
node2.childs += "one", "two"
I want to run:
python somescript.py somecommand
But, when I run this I need PYTHONPATH to include a certain directory. I can't just add it to my environment variables because the directory I want to add changes based on what project I'm running. Is there a way to alter PYTHONPATH while running a script? Note: I don't even have a PYTHONPATH variable, so I don't need to worry about appending to it vs overriding it during running of this script.
I wrote PyQt application. After it's start I close it (GUI), but timer don't stops and Python sometimes freezes. Only thing to unfreeze it - Ctrl-C, after which following message appears:
Traceback (most recent call last):
File "", line 262, in timerEvent
KeyboardInterrupt
timer don't stops again, and CPython works very slowly. How to avoid this problem?
How are lists in python stored internally? Is it an array? A linked list? Something else?
Or does the interpreter guess at the right structure for each instance based on length, etc.
If the question is implementation dependent, what about the classic CPython?