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
import time
def getElapsedTime(startTime, units):
elapsedInSeconds = time.time() - startTime
if units == 'sec':
return elapsedInSeconds
if units == 'min':
return elapsedInSeconds/60
if units == 'hour':
return elapsedInSeconds/(60*60)
其他回答
对于Python 3
如果使用时间模块,则可以获取当前时间戳,然后执行代码,然后再次获取时间戳。现在,所用时间将是第一个时间戳减去第二个时间戳:
import time
first_stamp = int(round(time.time() * 1000))
# YOUR CODE GOES HERE
time.sleep(5)
second_stamp = int(round(time.time() * 1000))
# Calculate the time taken in milliseconds
time_taken = second_stamp - first_stamp
# To get time in seconds:
time_taken_seconds = round(time_taken / 1000)
print(f'{time_taken_seconds} seconds or {time_taken} milliseconds')
我喜欢简单(python 3):
from timeit import timeit
timeit(lambda: print("hello"))
单个执行的输出为微秒:
2.430883963010274
说明:timeit默认执行匿名函数100万次,结果以秒为单位。因此,1次执行的结果相同,但平均以微秒为单位。
对于速度较慢的操作,添加较少的迭代次数,否则您可能会一直等待:
import time
timeit(lambda: time.sleep(1.5), number=1)
总迭代次数的输出始终以秒为单位:
1.5015795179999714
测量时间(秒):
from timeit import default_timer as timer
from datetime import timedelta
start = timer()
# ....
# (your code runs here)
# ...
end = timer()
print(timedelta(seconds=end-start))
输出:
0:00:01.946339
我参加聚会已经很晚了,但这种方法以前没有涉及过。当我们想要手动对某段代码进行基准测试时,我们可能需要首先找出哪些类方法占用了执行时间,这有时并不明显。我构建了以下元类来解决这个问题:
from __future__ import annotations
from functools import wraps
from time import time
from typing import Any, Callable, TypeVar, cast
F = TypeVar('F', bound=Callable[..., Any])
def timed_method(func: F, prefix: str | None = None) -> F:
prefix = (prefix + ' ') if prefix else ''
@wraps(func)
def inner(*args, **kwargs): # type: ignore
start = time()
try:
ret = func(*args, **kwargs)
except BaseException:
print(f'[ERROR] {prefix}{func.__qualname__}: {time() - start}')
raise
print(f'{prefix}{func.__qualname__}: {time() - start}')
return ret
return cast(F, inner)
class TimedClass(type):
def __new__(
cls: type[TimedClass],
name: str,
bases: tuple[type[type], ...],
attrs: dict[str, Any],
**kwargs: Any,
) -> TimedClass:
for name, attr in attrs.items():
if isinstance(attr, (classmethod, staticmethod)):
attrs[name] = type(attr)(timed_method(attr.__func__))
elif isinstance(attr, property):
attrs[name] = property(
timed_method(attr.fget, 'get') if attr.fget is not None else None,
timed_method(attr.fset, 'set') if attr.fset is not None else None,
timed_method(attr.fdel, 'del') if attr.fdel is not None else None,
)
elif callable(attr):
attrs[name] = timed_method(attr)
return super().__new__(cls, name, bases, attrs)
它允许如下使用:
class MyClass(metaclass=TimedClass):
def foo(self):
print('foo')
@classmethod
def bar(cls):
print('bar')
@staticmethod
def baz():
print('baz')
@property
def prop(self):
print('prop')
@prop.setter
def prop(self, v):
print('fset')
@prop.deleter
def prop(self):
print('fdel')
c = MyClass()
c.foo()
c.bar()
c.baz()
c.prop
c.prop = 2
del c.prop
MyClass.bar()
MyClass.baz()
它打印:
foo
MyClass.foo: 1.621246337890625e-05
bar
MyClass.bar: 4.5299530029296875e-06
baz
MyClass.baz: 4.291534423828125e-06
prop
get MyClass.prop: 3.814697265625e-06
fset
set MyClass.prop: 3.5762786865234375e-06
fdel
del MyClass.prop: 3.5762786865234375e-06
bar
MyClass.bar: 3.814697265625e-06
baz
MyClass.baz: 4.0531158447265625e-06
它可以与其他答案相结合,以更精确的方式代替time.time。
import time
def getElapsedTime(startTime, units):
elapsedInSeconds = time.time() - startTime
if units == 'sec':
return elapsedInSeconds
if units == 'min':
return elapsedInSeconds/60
if units == 'hour':
return elapsedInSeconds/(60*60)