""" timethis.py Author : David Beazley http://www.dabeaz.com Copyright (C) 2010 timethis is a utility library for making simple timing benchmarks. A single function timethis() is provided. The function operates as either a context manager or a decorator. Here are some examples. If you want to time a block of code, do this: with timethis("Counting to a million"): n = 0 while n < 1000000: n += 1 The string in quotes is a description that describes the code block in question. It will be printed in the output. If you want to time a function, you can use a decorator: @timethis def count_to_a_million(): n = 0 while n < 1000000: n += 1 count_to_a_million() All timing output is collected and not printed until a program exits. If any code block or function marked with timethis() is executed more than once, timing measurements are collected and used to calculate a mean and standard deviation. """ import atexit import time import math from contextlib import contextmanager from collections import defaultdict # Dictionary holding timing measurements _stats = defaultdict(list) # Exit processing to print performance results def _printstats(): if not _stats: return maxwidth = max(len(str(key)) for key in _stats) for key,times in sorted(_stats.items(),key=lambda x: str(x[0])): # Compute average and standard deviation mean = sum(times)/float(len(times)) stddev = math.sqrt(sum((x-mean)**2 for x in times)/len(times)) print("{0:<{maxwidth}s} : {1:0.5f}s : N={2:5d} : stddev={3:0.5f}".format( key,mean,len(times),stddev,maxwidth=maxwidth)) atexit.register(_printstats) # This utility function is used to perform timing benchmarks def timethis(what): @contextmanager def benchmark(): start = time.time() yield end = time.time() _stats[what].append(end-start) if hasattr(what,"__call__"): def timed(*args,**kwargs): with benchmark(): return what(*args,**kwargs) return timed else: return benchmark() # Example if __name__ == '__main__': # A single measurement with timethis("count to ten million"): n = 0 while n < 10000000: n += 1 # Repeated measurements for i in range(10): with timethis("count to one million"): n = 0 while n < 1000000: n += 1 # A function call @timethis def count_to_a_million(): n = 0 while n < 1000000: n += 1 count_to_a_million() count_to_a_million() count_to_a_million()