How to find where a Python class is defined

One way to get the location of a class is using a combination of the __module__ attribute of a class and the sys.modules dictionary.

Example:

import sys
from stl import stl

module = sys.modules[stl.BaseStl.__module__]
print module.__file__

I should note that this doesn't always give the correct module, it just gives the module where you got it from. A more thorough (but slower) method is using the inspect module:

from stl import stl
import inspect

print inspect.getmodule(stl.BaseStl).__file__

Let's explain by example

import numpy
print numpy.__file__

gives

/usr/lib64/python2.7/site-packages/numpy/__init__.pyc

on my machine.

If you only have a class, you can use that class with the python2-ic imp module:

#let unknownclass be looked for

import imp

modulename = unknownclass.__module__
tup = imp.find_module(modulename)
#(None, '/usr/lib64/python2.7/site-packages/numpy', ('', '', 5))
print "path to module", modulename, ":", tup[1]
#path to module numpy : /usr/lib64/python2.7/site-packages/numpy

As you can see, the __module__ property is probably what you're looking for.

You can use the inspect module to get the location where a module/package is defined.

inspect.getmodule(my_class)

Sample Output:

<module 'module_name' from '/path/to/my/module.py'>

As per the docs,

inspect.getmodule(object)
Try to guess which module an object was defined in.