from timeit import timeit from time import perf_counter as time from statistics import mean, stdev import sys def short(): try: if 0 == 1: unreached raise RuntimeError except RuntimeError: pass def long(): try: if 0 == 1: unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached; unreached raise RuntimeError except RuntimeError: pass funcs = short, long for _ in range(3): times = {f: [] for f in funcs} def stats(f): ts = [t * 1e9 for t in sorted(times[f])[:5]] return f'{mean(ts):6.1f} ± {stdev(ts):4.1f} ns ' for _ in range(100): for f in funcs: t = timeit(f, number=10**4) / 1e4 times[f].append(t) for f in sorted(funcs, key=stats): print(stats(f), f.__name__) print() print('Python:', sys.version)

from time import perf_counter as time from timeit import repeat for e in range(2, 6): n = 10 ** e exec(f'''def f():  if 0 == 1:  {'unreached;' * n}  try:  raise RuntimeError  except RuntimeError:  pass''') number = 10**6 // n t = min(repeat(f, number=number)) / number print(f'{n:6} {t * 1e6 :7.1f} μs')

from timeit import timeit from statistics import mean, stdev from itertools import repeat, starmap, islice import sys def one_nested(iterable, too_short=None, too_long=None): it = iter(iterable) for first in it: for second in it: raise too_long or ValueError( 'Expected exactly one item in iterable, but', f'got {first!r}, {second!r}, and perhaps more.' ) return first raise too_short or ValueError('too few items in iterable (expected 1)') def one_sequential(iterable, too_short=None, too_long=None): it = iter(iterable) for first in it: break else: raise too_short or ValueError('too few items in iterable (expected 1)') for second in it: raise too_long or ValueError( 'Expected exactly one item in iterable, but ' f'got {first!r}, {second!r}, and perhaps more.' ) return first funcs = one_nested, one_sequential def empty(f): iterable = iter(()) too_short = RuntimeError() for _ in repeat(None, 10**4): try: f(iterable, too_short) except RuntimeError: pass for case in empty,: times = {f: [] for f in funcs} def stats(f): ts = [t * 1e9 for t in sorted(times[f])[:5]] return f'{mean(ts):6.1f} ± {stdev(ts):4.1f} ns ' for _ in range(100): for f in funcs: t = timeit(lambda: case(f), number=1) / 1e4 times[f].append(t) for f in sorted(funcs, key=stats): print(stats(f), f.__name__) print() print('Python:', sys.version)