我有一个Python命令行程序,需要一段时间才能完成。我想知道完成跑步所需的确切时间。
我看过timeit模块,但它似乎只适用于小代码片段。我想给整个节目计时。
我有一个Python命令行程序,需要一段时间才能完成。我想知道完成跑步所需的确切时间。
我看过timeit模块,但它似乎只适用于小代码片段。我想给整个节目计时。
当前回答
import time
start_time = time.clock()
main()
print(time.clock() - start_time, "seconds")
time.clock()返回处理器时间,它允许我们仅计算此进程使用的时间(无论如何,在Unix上)。文档中说“无论如何,这是用于Python基准测试或计时算法的函数”
其他回答
稍后回答,但我使用内置的timeit:
import timeit
code_to_test = """
a = range(100000)
b = []
for i in a:
b.append(i*2)
"""
elapsed_time = timeit.timeit(code_to_test, number=500)
print(elapsed_time)
# 10.159821493085474
在code_to_test中包装所有代码,包括可能的任何导入。number参数指定代码应该重复的次数。演示
这是保罗·麦奎尔的回答,对我来说很有用。以防有人在运行这个问题时遇到问题。
import atexit
from time import clock
def reduce(function, iterable, initializer=None):
it = iter(iterable)
if initializer is None:
value = next(it)
else:
value = initializer
for element in it:
value = function(value, element)
return value
def secondsToStr(t):
return "%d:%02d:%02d.%03d" % \
reduce(lambda ll,b : divmod(ll[0],b) + ll[1:],
[(t*1000,),1000,60,60])
line = "="*40
def log(s, elapsed=None):
print (line)
print (secondsToStr(clock()), '-', s)
if elapsed:
print ("Elapsed time:", elapsed)
print (line)
def endlog():
end = clock()
elapsed = end-start
log("End Program", secondsToStr(elapsed))
def now():
return secondsToStr(clock())
def main():
start = clock()
atexit.register(endlog)
log("Start Program")
导入文件后,从程序中调用timing.main()。
在Linux或Unix中:
$ time python yourprogram.py
在Windows中,请参阅StackOverflow问题:如何在Windows命令行上测量命令的执行时间?
对于更详细的输出,
$ time -v python yourprogram.py
Command being timed: "python3 yourprogram.py"
User time (seconds): 0.08
System time (seconds): 0.02
Percent of CPU this job got: 98%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.10
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 9480
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 0
Minor (reclaiming a frame) page faults: 1114
Voluntary context switches: 0
Involuntary context switches: 22
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
我定义了以下Python装饰器:
def profile(fct):
def wrapper(*args, **kw):
start_time = time.time()
ret = fct(*args, **kw)
print("{} {} {} return {} in {} seconds".format(args[0].__class__.__name__,
args[0].__class__.__module__,
fct.__name__,
ret,
time.time() - start_time))
return ret
return wrapper
并将其用于函数或类/方法:
@profile
def main()
...
以下代码段以可读的<HH:MM:SS>格式打印经过的时间。
import time
from datetime import timedelta
start_time = time.time()
#
# Perform lots of computations.
#
elapsed_time_secs = time.time() - start_time
msg = "Execution took: %s secs (Wall clock time)" % timedelta(seconds=round(elapsed_time_secs))
print(msg)