Python introspection - how to check current module / line of call from within function

Question

I have a function:

# utils.py
def hello(name='World'):
    # Detect where I'm being called from.
    print('Hi, %s. You called this from %s at line # %d.' % (name, mod, lineno))
    # ``mod`` and ``lineno`` on previous line would have been set in real use.

I import that function and run it elsewhere

# other.py (this comment at line # 138)
from utils import hello
hello('Johnny')  # From inside ``hello`` I want to be able to detect that this
# was called from other.py at line # 140

Answer 1

Access the enclosing frame of inspect.currentframe():

import inspect

def hello(name='World'):
    f = inspect.currentframe().f_back
    mod = f.f_code.co_filename
    lineno = f.f_lineno
    print('Hi, %s. You called this from %s at line # %d.' %
          (name, mod, lineno))

Answer 2

The traceback module lets you extract the stack, so you can see how you reached the current stack frame. If you want you can extend this to print the caller-of-caller, as far up the stack as you like:

import traceback

def _trace():
    stack = traceback.extract_stack()[-3:-1]
    path, line, in_func, _instr = stack[0]
    print 'called from %s in func %s at line %s' % (path, in_func, line)

def bar():
    _trace()

def foo():
    bar()
    baz()

def baz():
    bar()

bar()
foo()

Output:

called from hello.py in func <module> at line 20
called from hello.py in func foo at line 14
called from hello.py in func baz at line 18