#!/usr/bin/env python3

# encoding: utf-8

import sys

def trace_calls(frame, event, arg):

if event != 'call':

return

co = frame.f_code

func_name = co.co_name

if func_name == 'write':

# Ignore write() calls from printing

return

func_line_no = frame.f_lineno

func_filename = co.co_filename

if not func_filename.endswith('sys_settrace_call.py'):

# Ignore calls not in this module

return

caller = frame.f_back

caller_line_no = caller.f_lineno

caller_filename = caller.f_code.co_filename

print('* Call to', func_name)

print('* on line {} of {}'.format(

func_line_no, func_filename))

print('* from line {} of {}'.format(

caller_line_no, caller_filename))

return

def b():

print('inside b()\n')

def a():

print('inside a()\n')

b()

sys.settrace(trace_calls)

a()