why the following python program does not face any concurrency problems without synchronize mechanism?
from threading import Thread def calc(start, end): total = 0; for i in range(start, end + 1): total += i; print '--result:', total return total t = Thread(target=calc, args=(1,100)) t.start() I have run this program for many times,and the result is always 5050, if there is any concurrency problem, the result should not be 5050, which is never met, anyhow I mean this program should get the wrong answer at some times, but this never happens, why? can concurrency without synchronize mechanism always get the right answer? any special case in python programming? -- http://mail.python.org/mailman/listinfo/python-list
Any suggestion to start more threads at the same time?
I start many threads in order to make the work done, when the concurrent number is set to 300, all thing just works fine, but when the number is set to 350 or higher, error just comes out? what's wrong ? the error info is just as follows: failed to start . I am confused, does this have something to do with the operating system, i am now using Linux, any suggestion to make the system to support more python threads? thank you :) -- http://mail.python.org/mailman/listinfo/python-list
python import error, what's wrong?
I am using pydev plugin in eclipse, all things works just as well but now i have confronted with a confusing problem, that is i can import a module write by myself successfully, but when i try to run this program, error just shows up, what's wrong? the directory structure is as follows: src org.test A.py org.lab B.py contents of A seems like: class A ... contents of B seems like: // I try to run B.py, python import error just appears, why? from org.test.A import A a = A() -- http://mail.python.org/mailman/listinfo/python-list
How to define repeated string when using the re module?
if it's for a single character, this should be very easy, such as
c{m,n} the occurrence of c is between m and n,
if i want to define the occurrence of (.*?) how should make it
done? ((.*?)){1,3} seems not work, any method to define repeat
string using python regex?
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how to sort a hash list without generating a new object?
the source code is as follows
x={}
x['a'] = 11
x['c'] = 19
x['b'] = 13
print x
tmp = sorted(x.items(), key = lambda x:x[0])# increase order by
default, if i want to have a descending order, what should i do?
# after sorted is called, a list will be generated, and the hash list
x is not changed at all, how to convert x to a sorted hash list
without generating a new object?
print tmp
print x
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what is the advantage of Django when comparing with LAMP and J2EE platform?
There are so many choice to do the same thing, so is there any special advantage Django brings to user? -- http://mail.python.org/mailman/listinfo/python-list
can virtualenv run without the main installation?
At first i have a python environment, after using virtualenv test command, a new environment named test is created, in that directory have some of the executable commands such as python.exe, so can i program without the main installation of python? -- http://mail.python.org/mailman/listinfo/python-list
Re: can virtualenv run without the main installation?
env create by virtualenv will refer to the main env, how did it find the main env, is there any configuration files, if yes, where is it? 2011/8/6 smith jack : > At first i have a python environment, after using virtualenv test > command, a new environment named test is created, in that directory > have some of the executable commands > such as python.exe, so can i program without the main installation of python? > -- http://mail.python.org/mailman/listinfo/python-list
How to make the program support communication behind NAT device?
The subnet behind my router is 192.168.1.0/24, my pc ip is 192.168.1.9, the server written with python is hosted on 192.168.1.3 on port 1033, i can connect to this server from my pc But cannot connect to this server when outside of this subnet? why? I have made port translate on router, that is 10.10.9.2:1033 to 192.168.1.3:1033 what's wrong? -- http://mail.python.org/mailman/listinfo/python-list
how to separate a list into two lists?
if a list L is composed with tuple consists of two elements, that is L = [(a1, b1), (a2, b2) ... (an, bn)] is there any simple way to divide this list into two separate lists , such that L1 = [a1, a2... an] L2=[b1,b2 ... bn] i do not want to use loop, any methods to make this done? -- http://mail.python.org/mailman/listinfo/python-list
module import error, what's wrong?
from common.URLTool import URLTool tool = URLTool() Traceback (most recent call last): File "E:\workspace\url\test.py", line 7, in ? from common.URLTool import URLTool ImportError: No module named common.URLTool URLTools is a class write by myself, it works well ,but cannot be imported in the other package, what's wrong? -- http://mail.python.org/mailman/listinfo/python-list
How to use python environment created using virtualenv?
I have created a python environment using virtualenv, but when i want to import such environment to PyDev, error just appears, it tells there should be a Libs dir, but there is no Libs DIr in the virtual envronment created using virtualenv, what should i do if i want to use this virtual environment? -- http://mail.python.org/mailman/listinfo/python-list
Anyone here can do a comparation between Djang and RoR
what is the advantage of Django over RoR:) -- http://mail.python.org/mailman/listinfo/python-list
How to install easy_install on windows ?
it needs read registry, but the python i used is extracted from .zip, so there is no record in the registry, what should i do in order to install easy_install for my python environment? -- http://mail.python.org/mailman/listinfo/python-list
Failed to create virtual environment when using --relocatable option, what's wrong?
all things works well without --relocatable option, the error info when using --relocatable option is as follows : F:\PythonEnv\djangoEnv>virtualenv f:\PythonEnv\djangoEnv2 --relocatable PYTHONHOME is set. You *must* activate the virtualenv before using it The environment doesn't have a file f:\PythonEnv\djangoEnv2\Scripts\activate_thi s.py -- please re-run virtualenv on this environment to update it Traceback (most recent call last): File "E:\Tools\gov\tools\chrome_python\Scripts\virtualenv-script.py", line 7, in ? sys.exit( File "e:\tools\gov\tools\chrome_python\lib\site-packages\virtualenv-1.6.4-py2. 4.egg\virtualenv.py", line 802, in main make_environment_relocatable(home_dir) File "e:\tools\gov\tools\chrome_python\lib\site-packages\virtualenv-1.6.4-py2. 4.egg\virtualenv.py", line 1338, in make_environment_relocatable fixup_scripts(home_dir) File "e:\tools\gov\tools\chrome_python\lib\site-packages\virtualenv-1.6.4-py2. 4.egg\virtualenv.py", line 1357, in fixup_scripts for filename in os.listdir(bin_dir): WindowsError: [Errno 3] : 'f:\\PythonEnv\\djangoEnv2\\Scripts/*.*' -- http://mail.python.org/mailman/listinfo/python-list
why i cannot import djang?
this package is already in the site-packages directory, but i cannot import it , it's really confusing ... -- http://mail.python.org/mailman/listinfo/python-list
Some warning appears when installing virtualenv, does it matters?
the warning is just as follows E:\Tools>pip install virtualenv Downloading/unpacking virtualenv Downloading virtualenv-1.6.4.tar.gz (1.9Mb): 1.9Mb downloaded Running setup.py egg_info for package virtualenv warning: no previously-included files matching '*.*' found under directory ' docs\_templates' Installing collected packages: virtualenv Running setup.py install for virtualenv warning: no previously-included files matching '*.*' found under directory ' docs\_templates' Installing virtualenv-script.py script to E:\Tools\gov\tools\py_build\Script s Installing virtualenv.exe script to E:\Tools\gov\tools\py_build\Scripts Installing virtualenv.exe.manifest script to E:\Tools\gov\tools\py_build\Scr ipts Successfully installed virtualenv Cleaning up... -- http://mail.python.org/mailman/listinfo/python-list
How to build python using visual studio 2005?
anybody here have build it correctly? how to make a msi file just as the official site did? is there any detailed tutorial online? -- http://mail.python.org/mailman/listinfo/python-list
is there any principle when writing python function
i have heard that function invocation in python is expensive, but make lots of functions are a good design habit in many other languages, so is there any principle when writing python function? for example, how many lines should form a function? -- http://mail.python.org/mailman/listinfo/python-list
why i cannot invoke python script using command line?
but i can invoke it in eclipse, what's wrong? the script refered to another python script in eclipse project. f:\project\src\a.py f:\project\src\lib\b.py there is such lines in a.py from lib import b i can invoke a.py very well in eclipse but failed when using python f:\project\src\a.py, what's wrong? (the error msg shows a.py cannot find b.py) , what should i do in order to run a.py using command line? -- http://mail.python.org/mailman/listinfo/python-list
