profile and pstats — 性能分析

yunx Profiler

# profile_fibonacci_raw.py
import profile


def fib(n):
    # from literateprograms.org
    # http://bit.ly/hlOQ5m
    if n == 0:
        return 0
    elif n == 1:
        return 1
    else:
        return fib(n - 1) + fib(n - 2)


def fib_seq(n):
    seq = []
    if n > 0:
        seq.extend(fib_seq(n - 1))
    seq.append(fib(n))
    return seq


profile.run('print(fib_seq(20)); print()')

# profile_fibonacci_memoized.py
import functools
import profile


@functools.lru_cache(maxsize=None)
def fib(n):
    # from literateprograms.org
    # http://bit.ly/hlOQ5m
    if n == 0:
        return 0
    elif n == 1:
        return 1
    else:
        return fib(n - 1) + fib(n - 2)


def fib_seq(n):
    seq = []
    if n > 0:
        seq.extend(fib_seq(n - 1))
    seq.append(fib(n))
    return seq


if __name__ == '__main__':
    profile.run('print(fib_seq(20)); print()')

Running in a Context

# profile_runctx.py
import profile
from profile_fibonacci_memoized import fib, fib_seq

if __name__ == '__main__':
    profile.runctx(
        'print(fib_seq(n)); print()',
        globals(),
        {'n': 20},
    )

pstats: Saving and Working With Statistics

# profile_stats.py
import cProfile as profile
import pstats
from profile_fibonacci_memoized import fib, fib_seq

# Create 5 set of stats
for i in range(5):
    filename = 'profile_stats_{}.stats'.format(i)
    profile.run('print({}, fib_seq(20))'.format(i), filename)

# Read all 5 stats files into a single object
stats = pstats.Stats('profile_stats_0.stats')
for i in range(1, 5):
    stats.add('profile_stats_{}.stats'.format(i))

# Clean up filenames for the report
stats.strip_dirs()

# Sort the statistics by the cumulative time spent
# in the function
stats.sort_stats('cumulative')

stats.print_stats()

Limiting Report Contents

# profile_stats_restricted.py
import profile
import pstats
from profile_fibonacci_memoized import fib, fib_seq

# Read all 5 stats files into a single object
stats = pstats.Stats('profile_stats_0.stats')
for i in range(1, 5):
    stats.add('profile_stats_{}.stats'.format(i))
stats.strip_dirs()
stats.sort_stats('cumulative')

# limit output to lines with "(fib" in them
stats.print_stats('\(fib')

Caller / Callee Graphs

# profile_stats_callers.py
import cProfile as profile
import pstats
from profile_fibonacci_memoized import fib, fib_seq

# Read all 5 stats files into a single object
stats = pstats.Stats('profile_stats_0.stats')
for i in range(1, 5):
    stats.add('profile_stats_{}.stats'.format(i))
stats.strip_dirs()
stats.sort_stats('cumulative')

print('INCOMING CALLERS:')
stats.print_callers('\(fib')

print('OUTGOING CALLEES:')
stats.print_callees('\(fib')