如何让 `cProfile.run` 记录调用 `str` 所消耗的时间? [英] How do I get `cProfile.run` to log time consumed by calls to `str`?

问题描述

我正在尝试分析一些对 str 进行大量调用的代码的性能，看看我是否可以从替换其他方法来使用 str 中受益>，但我无法让 cProfile.run 显示对 str 的调用消耗了多少时间.

I'm trying to analyze the performance of some code that makes a lot of calls to str to see if I can benefit from substituting other approaches for the use of str, but I can't get cProfile.run to show me how much time calls to str are consuming.

例如，如果我测试(废话)代码

For example if I test the (nonsense) code

def foo(n):
    x = ''
    for i in range(n):
        x += str(n)
        x = str(len(str(n)))

使用 cProfile.run('foo(1000000)') 我没有提到必须对 str 进行的许多调用:

with cProfile.run('foo(1000000)') I get no mention of the many calls that must have been made to str:

         1000004 function calls in 1.163 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.000    0.000    1.163    1.163 <string>:1(<module>)
        1    1.046    1.046    1.163    1.163 example.py:172(foo)
  1000000    0.081    0.000    0.081    0.000 {len}
        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}
        1    0.036    0.036    0.036    0.036 {range}

如何让 cProfile.run 显示对 str 的调用的统计信息?

How do I get cProfile.run to show statistics for calls to str?

推荐答案

我不知道为什么它不显示对 str 的调用，但是您可以轻松绕过这种行为(为了仅用于分析)，通过覆盖内置的 str.

I'm not sure why it does not display the calls to str, but you can easily bypass this behavior (for the sake of profiling only), by overriding the builtin str.

只需将此代码添加到脚本的顶部，或者在调用 cProfile 之前:

Simply add this code at the top of your script, or before invoking cProfile:

orig_str = __builtin__.str
def mystr(*a, **kw): return orig_str(*a, **kw)
__builtin__.str = mystr

这可能与原始代码不完全兼容(例如，如果您的代码中有一些地方可以执行诸如 if type(x) == str 之类的事情)，但希望它可以在您的案例.

This might not be completely compatible with the original code (e.g. if you have places in your code which do things like if type(x) == str), but hopefully it would work in your case.

这篇关于如何让 `cProfile.run` 记录调用 `str` 所消耗的时间?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！