我想测量执行一个函数所花费的时间。我没时间工作:
import timeit
start = timeit.timeit()
print("hello")
end = timeit.timeit()
print(end - start)
我想测量执行一个函数所花费的时间。我没时间工作:
import timeit
start = timeit.timeit()
print("hello")
end = timeit.timeit()
print(end - start)
当前回答
这是另一种方法:
>> from pytictoc import TicToc
>> t = TicToc() # create TicToc instance
>> t.tic() # Start timer
>> # do something
>> t.toc() # Print elapsed time
Elapsed time is 2.612231 seconds.
与传统方式相比:
>> from time import time
>> t1 = time()
>> # do something
>> t2 = time()
>> elapsed = t2 - t1
>> print('Elapsed time is %f seconds.' % elapsed)
Elapsed time is 2.612231 seconds.
安装:
pip install pytictoc
有关详细信息,请参阅PyPi页面。
其他回答
作为lambda,获取经过的时间和时间戳:
import datetime
t_set = lambda: datetime.datetime.now().astimezone().replace(microsecond=0)
t_diff = lambda t: str(t_set() - t)
t_stamp = lambda t=None: str(t) if t else str(t_set())
在实践中:
>>>
>>> t_set()
datetime.datetime(2021, 3, 21, 1, 25, 17, tzinfo=datetime.timezone(datetime.timedelta(days=-1, seconds=61200), 'PDT'))
>>> t = t_set()
>>> t_diff(t)
'0:00:14'
>>> t_diff(t)
'0:00:23'
>>> t_stamp()
'2021-03-21 01:25:57-07:00'
>>> t_stamp(t)
'2021-03-21 01:25:22-07:00'
>>>
还有一种使用timeit的方法:
from timeit import timeit
def func():
return 1 + 1
time = timeit(func, number=1)
print(time)
下面是另一个用于计时代码的上下文管理器-
用法:
from benchmark import benchmark
with benchmark("Test 1+1"):
1+1
=>
Test 1+1 : 1.41e-06 seconds
或者,如果您需要时间值
with benchmark("Test 1+1") as b:
1+1
print(b.time)
=>
Test 1+1 : 7.05e-07 seconds
7.05233786763e-07
基准.py:
from timeit import default_timer as timer
class benchmark(object):
def __init__(self, msg, fmt="%0.3g"):
self.msg = msg
self.fmt = fmt
def __enter__(self):
self.start = timer()
return self
def __exit__(self, *args):
t = timer() - self.start
print(("%s : " + self.fmt + " seconds") % (self.msg, t))
self.time = t
改编自http://dabeaz.blogspot.fr/2010/02/context-manager-for-timing-benchmarks.html
print_elapsed_time函数如下
def print_elapsed_time(prefix=''):
e_time = time.time()
if not hasattr(print_elapsed_time, 's_time'):
print_elapsed_time.s_time = e_time
else:
print(f'{prefix} elapsed time: {e_time - print_elapsed_time.s_time:.2f} sec')
print_elapsed_time.s_time = e_time
用这种方式
print_elapsed_time()
.... heavy jobs ...
print_elapsed_time('after heavy jobs')
.... tons of jobs ...
print_elapsed_time('after tons of jobs')
结果是
after heavy jobs elapsed time: 0.39 sec
after tons of jobs elapsed time: 0.60 sec
这个函数的优点和缺点是你不需要经过开始时间
除了ipython中的%timeit之外,您还可以使用%%timeit进行多行代码片段:
In [1]: %%timeit
...: complex_func()
...: 2 + 2 == 5
...:
...:
1 s ± 1.93 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)
同样,它也可以以同样的方式在jupyter笔记本中使用,只需将magic%%timeit放在单元格的开头。