How can I get the source code of a Python function?

Question

Suppose I have a Python function as defined below:

def foo(arg1,arg2):
    #do something with args
    a = arg1 + arg2
    return a

I can g

Answer 1

Since this post is marked as the duplicate of this other post, I answer here for the "lambda" case, although the OP is not about lambdas.

So, for lambda functions that are not defined in their own lines: in addition to marko.ristin's answer, you may wish to use mini-lambda or use SymPy as suggested in this answer.

• mini-lambda is lighter and supports any kind of operation, but works only for a single variable
• SymPy is heavier but much more equipped with mathematical/calculus operations. In particular it can simplify your expressions. It also supports several variables in the same expression.

Here is how you can do it using mini-lambda:

from mini_lambda import x, is_mini_lambda_expr
import inspect

def get_source_code_str(f):
    if is_mini_lambda_expr(f):
        return f.to_string()
    else:
        return inspect.getsource(f)

# test it

def foo(arg1, arg2):
    # do something with args
    a = arg1 + arg2
    return a

print(get_source_code_str(foo))
print(get_source_code_str(x ** 2))

It correctly yields

def foo(arg1, arg2):
    # do something with args
    a = arg1 + arg2
    return a

x ** 2

See mini-lambda documentation for details. I'm the author by the way ;)