Given a Python class, how can I inspect and find the place in my code where it is defined?

Question

I'm building a debugging tool.

IPython lets me do stuff like

MyCls??

And it will show me the source.

Answer 1

Here's a pretty good overview of many of Python's meta-info capabilities:

http://www.ibm.com/developerworks/library/l-pyint.html

Answer 2

sys.modules[MyCls.__module__].__file__

or

inspect.getsourcefile(MyCls)

There are more __xxx__ attributes on various objects you might find useful.

Answer 3

The inspect module has everything you need.

Answer 4

If you just want to see the source, inspect.getsource is a very direct way to do that; for more advanced uses (getting the source file, line numbers, etc), see other functions in inspect documented at the same URL just before getsource. Note that each such function will raise an exception if source is not available, so make sure to be within a try/except block when you call it, and handle the exception as appropriate for your case. (Also, as I might hope goes without saying, you do need to import inspect in your modules in which you want to call inspect functionality).