Get source code of calling function in python

Question

For debugging purposes I would like to get the source code of the function that has called my function. So in the following situation:

def calling_func():
 x = 123
 y = x + 1
 myfunc()
def myfunc():
 calling_source = f()

I would like a function f, such that calling_source becomes the string

"""
x = 123
y = x + 1
myfunc()
"""

Does such a function exist? I'm guessing that this might be possible with something like sys._current_frames and the inspect module.

• AMC: How about stackoverflow.com/questions/2654113/… + stackoverflow.com/questions/427453/… ?
• juanpa.arrivillaga: you need the source code programmatically as a str object? Why not just use a modern debugger in the text editor of your choice with break points etc? Then you can step through the call stack with the source code in front of you.
• Grismar: I'm voting to close for duplication, but apart from that: don't write your own debugger, that's generally a really bad idea, unless you have some crazy use case where that makes sense (or you're developing an editor / IDE, but then I wouldn't expect you here asking these questions).
• MRocklin: I appreciate the advice to use a debugger. I write tools for developers. I know what I'm doing here.
• Mad Physicist: Fair point. Question is valid regardless of your motives and background.

Answer 1

import sys
import inspect
def called():
 print(inspect.getsource(sys._getframe().f_back))
def caller():
 called()
 x = 123 # Some example code
 y = x + 1
caller()

Output:

def caller():
 called()
 x = 123 # Some example code
 y = x + 1

inspect.getsource(object) takes an object as parameter and returns the source code as string.

Answer 2

In [1]: import inspect 
In [2]: def calling_func(): 
 ...: x = 123 
 ...: y = x + 1 
 ...: text = f() 
 ...: print(text) 
 ...: 
In [3]: def f() -> str: 
 ...: frame = inspect.currentframe() 
 ...: frame = frame.f_back # go up one in the stack 
 ...: text = inspect.getsource(frame) 
 ...: return text 
 ...: 
In [4]: calling_func() 
def calling_func():
 x = 123
 y = x + 1
 text = f()
 print(text)