For a pure python module you can find the source by looking at themodule.__file__.
The datetime module, however, is written in C, and therefore datetime.__file__ points to a .so file (there is no datetime.__file__ on Windows), and therefore, you can't see the source.
If you download a python source tarball and extract it, the modules' code can be found in the Modules subdirectory.
For example, if you want to find the datetime code for python 2.6, you can look at
Python-2.6/Modules/datetimemodule.c
You can also find the latest Mercurial version on the web at https://hg.python.org/cpython/file/tip/Modules/_datetimemodule.c
Running python -v from the command line should tell you what is being imported and from where. This works for me on Windows and Mac OS X.
C:\>python -v
# installing zipimport hook
import zipimport # builtin
# installed zipimport hook
# C:\Python24\lib\site.pyc has bad mtime
import site # from C:\Python24\lib\site.py
# wrote C:\Python24\lib\site.pyc
# C:\Python24\lib\os.pyc has bad mtime
import os # from C:\Python24\lib\os.py
# wrote C:\Python24\lib\os.pyc
import nt # builtin
# C:\Python24\lib\ntpath.pyc has bad mtime
...
I'm not sure what those bad mtime's are on my install!
I realize this answer is 4 years late, but the existing answers are misleading people.
The right way to do this is never __file__, or trying to walk through sys.path and search for yourself, etc. (unless you need to be backward compatible beyond 2.1).
It's the inspect module—in particular, getfile or getsourcefile.
Unless you want to learn and implement the rules (which are documented, but painful, for CPython 2.x, and not documented at all for other implementations, or 3.x) for mapping .pyc to .py files; dealing with .zip archives, eggs, and module packages; trying different ways to get the path to .so/.pyd files that don't support __file__; figuring out what Jython/IronPython/PyPy do; etc. In which case, go for it.
Meanwhile, every Python version's source from 2.0+ is available online at http://hg.python.org/cpython/file/X.Y/ (e.g., 2.7 or 3.3). So, once you discover that inspect.getfile(datetime) is a .so or .pyd file like /usr/local/lib/python2.7/lib-dynload/datetime.so, you can look it up inside the Modules directory. Strictly speaking, there's no way to be sure of which file defines which module, but nearly all of them are either foo.c or foomodule.c, so it shouldn't be hard to guess that datetimemodule.c is what you want.
from the standard library try imp.find_module
>>> import imp
>>> imp.find_module('fontTools')
(None, 'C:\\Python27\\lib\\site-packages\\FontTools\\fontTools', ('', '', 5))
>>> imp.find_module('datetime')
(None, 'datetime', ('', '', 6))
Here's a one-liner to get the filename for a module, suitable for shell aliasing:
echo 'import sys; t=__import__(sys.argv[1],fromlist=[\".\"]); print(t.__file__)' | python -
Set up as an alias:
alias getpmpath="echo 'import sys; t=__import__(sys.argv[1],fromlist=[\".\"]); print(t.__file__)' | python - "
To use:
$ getpmpath twisted
/usr/lib64/python2.6/site-packages/twisted/__init__.pyc
$ getpmpath twisted.web
/usr/lib64/python2.6/site-packages/twisted/web/__init__.pyc
In the python interpreter you could import the particular module and then type help(module). This gives details such as Name, File, Module Docs, Description et al.
Ex:
import os
help(os)
Help on module os:
NAME
os - OS routines for Mac, NT, or Posix depending on what system we're on.
FILE
/usr/lib/python2.6/os.py
MODULE DOCS
http://docs.python.org/library/os
DESCRIPTION
This exports:
- all functions from posix, nt, os2, or ce, e.g. unlink, stat, etc.
- os.path is one of the modules posixpath, or ntpath
- os.name is 'posix', 'nt', 'os2', 'ce' or 'riscos'
et al
New in Python 3.2, you can now use e.g. code_info() from the dis module:
http://docs.python.org/dev/whatsnew/3.2.html#dis
Check out this nifty "cdp" command to cd to the directory containing the source for the indicated Python module:
cdp () {
cd "$(python -c "import os.path as _, ${1}; \
print _.dirname(_.realpath(${1}.__file__[:-1]))"
)"
}
Another way to check if you have multiple python versions installed, from the terminal.
-MBP:~python3 -m pip show pyperclip
Location: /Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-
MBP:~ python -m pip show pyperclip
Location: /Users/umeshvuyyuru/Library/Python/2.7/lib/python/site-packages
For those who prefer a GUI solution: if you're using a gui such as Spyder (part of the Anaconda installation) you can just right-click the module name (such as "csv" in "import csv") and select "go to definition" - this will open the file, but also on the top you can see the exact file location ("C:....csv.py")
If you are not using interpreter then you can run the code below:
import site
print (site.getsitepackages())
Output:
['C:\\Users\\<your username>\\AppData\\Local\\Programs\\Python\\Python37', 'C:\\Users\\<your username>\\AppData\\Local\\Programs\\Python\\Python37\\lib\\site-packages']
The second element in Array will be your package location. In this case:
C:\Users\<your username>\AppData\Local\Programs\Python\Python37\lib\site-packages
In an IDE like Spyder, import the module and then run the module individually. enter image description here
