"""
Result:
main->sub1 	 0.10152816772460938
main->sub2 	 0.20150494575500488
main 	 0.31107306480407715
main2->sub1 	 0.30101609230041504
main2->sub2 	 0.4036266803741455
main2 	 0.7056293487548828
"""

import inspect
import time

def get_caller():
    for s in inspect.stack():
        f = s.frame.f_globals.get(s.function)
        attr = getattr(f, '__trace__', None)
        if attr:
            return attr

def trace(name):
    def real_trace(f):
        def wrapper(*a, **kw):
            start = time.time()
            caller = get_caller()
            try:
                return f(*a, **kw)
            finally:
                end = time.time()
                print(caller + "->" + name if caller else name, '\t', end - start)
        wrapper.__trace__ = name
        return wrapper
    return real_trace

@trace("main")
def main():
    sub1(0.1)
    sub2(0.2)

@trace("main2")
def main2():
    sub1(0.3)
    sub2(0.4)

@trace("sub1")
def sub1(n):
    time.sleep(n)

@trace("sub2")
def sub2(n):
    time.sleep(n)

main()
main2()