Snippet to paste before your python code to get a call graph

trace.py

# Place at the head of your main file

import sys
import atexit

def function_identifier(frame):
    code = frame.f_code
    name = code.co_name
    file = code.co_filename
    return "{}:{}".format(file, name)

cg = {}
def trace_calls(frame, event, arg):
    if event != 'call':
        return
    if frame.f_code.co_name == "print_calls":
        return
    global cg
    caller_f = frame.f_back
    yeh = "/opt/foo-demo/" # Wherever your code lives
    nyeh = "<frozen importlib."
    if frame.f_code.co_filename.startswith(nyeh):
        return
    while caller_f.f_back is not None and str(caller_f.f_code.co_filename).startswith(nyeh):
        caller_f = caller_f.f_back
    if caller_f.f_code.co_filename.startswith(nyeh):
        return
    callee = function_identifier(frame)
    caller = function_identifier(caller_f)
    if (not caller.startswith(yeh)) and (not callee.startswith(yeh)):
        return
    if caller in cg:
        cg[caller].add(callee)
    else:
        cg[caller] = {callee}

def print_calls():
    global gc
    print()
    print("digraph G {")
    print("    rankdir=\"LR\";")
    for caller, callees in cg.items():
        for callee in callees:
            print("    \"{}\" -> \"{}\"".format(caller, callee))
    print("}")

sys.settrace(trace_calls)
atexit.register(print_calls)