Python: Get source code of class (using inspect)

Question

I am using ipython and I want to save a class defined in one of my notebooks. I can do this with functions nicely with %save and inspect.getsource, but I cant seem to get the source of my class. I had a quick look at the methods in inspect and couldnt seem to find anything that could help. Any suggestions?

class A():
    def __init__(self):
        self.x = 1

%save filename.py inspect.getsource(A)

inspect.getsource(A)
>>> ...
>>> TypeError: <module '__main__'> is a built-in class

Answer 1

getsource works by actually opening the source file that defines the object you're looking at.

But, since you defined A in the interactive interpreter, there is no such source file, and therefore Python can't find one.

The error is somewhat obscure, but Python basically tries to look up the source file for A's module (A.__module__), which is __main__, and which has no __file__ property (because it didn't come from a file).