用装饰器记录执行时间 [英] Logging execution time with decorators

问题描述

尝试了一段时间失败后，我正在这个神奇的网站上寻求帮助.现在解决我的问题:我想创建一个装饰器，将一个函数的执行时间( 在该函数执行期间)写到以下日志文​​件中:

After I tried unsuccessfully for a while, I am seeking help from this miraculous website. Now for my problem: I want to create a decorator that writes the elapsed execution time of a function (during the execution of the function) into a logging file like:

@log_time("log.txt", 35)
def some_function(...):
    ...
    return result

和

from functools import wraps

def log_time(path_to_logfile, interval):
    ...

使 log.txt 看起来像

Time elapsed: 0h 0m 35s
Time elapsed: 0h 1m 10s
Time elapsed: 0h 1m 45s

有什么想法吗?

推荐答案

好吧，我最终发现了一些线程问题.感谢您的所有建议！

Okay, I figured something out in the end with threads. Thanks for all the suggestions!

import codecs, threading, time
from functools import wraps

def log_time(logpath="log.txt", interval=5):

    def log_time_decorator(func):
        @wraps(func)
        def wrapper(*args, **kwargs):
            t = threading.Thread(target=func, args=args, kwargs=kwargs)
            log_entries = 0
            with codecs.open(logpath, "wb", "utf-8") as logfile:
               start_time = time.time()
               t.start()
               while t.is_alive():
                   elapsed_time = (time.time() - start_time)
                   if elapsed_time > interval * log_entries:
                       m, s = divmod(elapsed_time, 60)
                       h, m = divmod(m, 60)
                       logfile.write("Elapsed time: %2dh %2dm %2ds\n" %(h, m, s))
                       log_entries += 1
        return wrapper
    return log_time_decorator

一个缺点可能是您无法轻松检索该函数的返回值(至少我还没有弄清楚它).

One disadvantage might be that you cannot easily retrieve the return value of the function (at least I haven't figured it out yet).

删除了不必要的变量并添加了一种不错的日志记录格式(请参见此)

Removed an unnecessary variable and added a nice format for logwriting (see this)

即使其他用户拒绝了他的编辑，我也想加入 Piotr Dabkowski ，因为它可以使用返回值:

Even though other users rejected his edit, I want to include a version from Piotr Dabkowski because it works with a return-value:

def log_time(logpath="log.txt", interval=5):

    def log_time_decorator(func):
        @wraps(func)
        def wrapper(*args, **kwargs):
            RESULT = [None]
            def temp():
                RESULT[0] = func(*args, **kwargs)
            t = threading.Thread(target=temp)
            log_entries = 0
            with codecs.open(logpath, "wb", "utf-8") as logfile:
               start_time = time.time()
               t.start()
               while t.is_alive():
                   elapsed_time = (time.time() - start_time)
                   if elapsed_time > interval * log_entries:
                       m, s = divmod(elapsed_time, 60)
                       h, m = divmod(m, 60)
                       logfile.write("Elapsed time: %2dh %2dm %2ds\n" %(h, m, s))
                       log_entries += 1
            return RESULT[0]
        return wrapper
    return log_time_decorator

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