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
我在查找两种不同方法的运行时间时遇到的问题,这两种方法用于查找所有<=一个数的素数。当在程序中进行用户输入时。
错误的方法
#Sample input for a number 20
#Sample output [2, 3, 5, 7, 11, 13, 17, 19]
#Total Running time = 0.634 seconds
import time
start_time = time.time()
#Method 1 to find all the prime numbers <= a Number
# Function to check whether a number is prime or not.
def prime_no(num):
if num<2:
return False
else:
for i in range(2, num//2+1):
if num % i == 0:
return False
return True
#To print all the values <= n
def Prime_under_num(n):
a = [2]
if n <2:
print("None")
elif n==2:
print(2)
else:
"Neglecting all even numbers as even numbers won't be prime in order to reduce the time complexity."
for i in range(3, n+1, 2):
if prime_no(i):
a.append(i)
print(a)
"When Method 1 is only used outputs of running time for different inputs"
#Total Running time = 2.73761 seconds #n = 100
#Total Running time = 3.14781 seconds #n = 1000
#Total Running time = 8.69278 seconds #n = 10000
#Total Running time = 18.73701 seconds #n = 100000
#Method 2 to find all the prime numbers <= a Number
def Prime_under_num(n):
a = [2]
if n <2:
print("None")
elif n==2:
print(2)
else:
for i in range(3, n+1, 2):
if n%i ==0:
pass
else:
a.append(i)
print(a)
"When Method 2 is only used outputs of running time for different inputs"
# Total Running time = 2.75935 seconds #n = 100
# Total Running time = 2.86332 seconds #n = 1000
# Total Running time = 4.59884 seconds #n = 10000
# Total Running time = 8.55057 seconds #n = 100000
if __name__ == "__main__" :
n = int(input())
Prime_under_num(n)
print("Total Running time = {:.5f} seconds".format(time.time() - start_time))
上述所有情况下获得的不同运行时间都是错误的。对于我们正在接受输入的问题,我们必须在接受输入后才开始计时。这里,用户键入输入所花费的时间也与运行时间一起计算。
正确的方法
我们必须从开头删除start_time=time.time()并将其添加到主块中。
if __name__ == "__main__" :
n = int(input())
start_time = time.time()
Prime_under_num(n)
print("Total Running time = {:.3f} seconds".format(time.time() - start_time))
因此,两种方法单独使用时的输出如下:-
# Method 1
# Total Running time = 0.00159 seconds #n = 100
# Total Running time = 0.00506 seconds #n = 1000
# Total Running time = 0.22987 seconds #n = 10000
# Total Running time = 18.55819 seconds #n = 100000
# Method 2
# Total Running time = 0.00011 seconds #n = 100
# Total Running time = 0.00118 seconds #n = 1000
# Total Running time = 0.00302 seconds #n = 10000
# Total Running time = 0.01450 seconds #n = 100000
现在我们可以看到,与错误方法相比,总运行时间有显著差异。即使方法2在两种方法中的性能优于方法1,但第一种方法(错误方法)是错误的。
其他回答
首先,以管理员身份打开命令提示符(CMD)并在那里键入,安装人性化的软件包-pip安装人性化
代码:
from humanfriendly import format_timespan
import time
begin_time = time.time()
# Put your code here
end_time = time.time() - begin_time
print("Total execution time: ", format_timespan(end_time))
输出:
我使用了一个非常简单的函数来计时代码执行的一部分:
import time
def timing():
start_time = time.time()
return lambda x: print("[{:.2f}s] {}".format(time.time() - start_time, x))
要使用它,只需在代码之前调用它来度量以检索函数计时,然后在代码之后调用带有注释的函数。时间将显示在评论前面。例如:
t = timing()
train = pd.read_csv('train.csv',
dtype={
'id': str,
'vendor_id': str,
'pickup_datetime': str,
'dropoff_datetime': str,
'passenger_count': int,
'pickup_longitude': np.float64,
'pickup_latitude': np.float64,
'dropoff_longitude': np.float64,
'dropoff_latitude': np.float64,
'store_and_fwd_flag': str,
'trip_duration': int,
},
parse_dates = ['pickup_datetime', 'dropoff_datetime'],
)
t("Loaded {} rows data from 'train'".format(len(train)))
然后输出将如下所示:
[9.35s] Loaded 1458644 rows data from 'train'
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。
$ python -mtimeit -n1 -r1 -t -s "from your_module import main" "main()"
它运行一次your_module.main()函数,并使用time.time()函数作为计时器打印经过的时间。
要在Python中模拟/usr/bin/time,请参阅带有/usr/bin/time:如何捕获计时信息但忽略所有其他输出?的Python子进程?。
要测量每个函数的CPU时间(例如,不要包括time.sleep()期间的时间),可以使用profile模块(Python 2上的cProfile):
$ python3 -mprofile your_module.py
如果您想使用与配置文件模块相同的计时器,可以将-p传递给上面的timeit命令。
请参见如何评测Python脚本?
我也喜欢Paul McGuire的回答,并提出了一个更符合我需求的上下文管理器表单。
import datetime as dt
import timeit
class TimingManager(object):
"""Context Manager used with the statement 'with' to time some execution.
Example:
with TimingManager() as t:
# Code to time
"""
clock = timeit.default_timer
def __enter__(self):
"""
"""
self.start = self.clock()
self.log('\n=> Start Timing: {}')
return self
def __exit__(self, exc_type, exc_val, exc_tb):
"""
"""
self.endlog()
return False
def log(self, s, elapsed=None):
"""Log current time and elapsed time if present.
:param s: Text to display, use '{}' to format the text with
the current time.
:param elapsed: Elapsed time to display. Dafault: None, no display.
"""
print s.format(self._secondsToStr(self.clock()))
if(elapsed is not None):
print 'Elapsed time: {}\n'.format(elapsed)
def endlog(self):
"""Log time for the end of execution with elapsed time.
"""
self.log('=> End Timing: {}', self.now())
def now(self):
"""Return current elapsed time as hh:mm:ss string.
:return: String.
"""
return str(dt.timedelta(seconds = self.clock() - self.start))
def _secondsToStr(self, sec):
"""Convert timestamp to h:mm:ss string.
:param sec: Timestamp.
"""
return str(dt.datetime.fromtimestamp(sec))
我在查找两种不同方法的运行时间时遇到的问题,这两种方法用于查找所有<=一个数的素数。当在程序中进行用户输入时。
错误的方法
#Sample input for a number 20
#Sample output [2, 3, 5, 7, 11, 13, 17, 19]
#Total Running time = 0.634 seconds
import time
start_time = time.time()
#Method 1 to find all the prime numbers <= a Number
# Function to check whether a number is prime or not.
def prime_no(num):
if num<2:
return False
else:
for i in range(2, num//2+1):
if num % i == 0:
return False
return True
#To print all the values <= n
def Prime_under_num(n):
a = [2]
if n <2:
print("None")
elif n==2:
print(2)
else:
"Neglecting all even numbers as even numbers won't be prime in order to reduce the time complexity."
for i in range(3, n+1, 2):
if prime_no(i):
a.append(i)
print(a)
"When Method 1 is only used outputs of running time for different inputs"
#Total Running time = 2.73761 seconds #n = 100
#Total Running time = 3.14781 seconds #n = 1000
#Total Running time = 8.69278 seconds #n = 10000
#Total Running time = 18.73701 seconds #n = 100000
#Method 2 to find all the prime numbers <= a Number
def Prime_under_num(n):
a = [2]
if n <2:
print("None")
elif n==2:
print(2)
else:
for i in range(3, n+1, 2):
if n%i ==0:
pass
else:
a.append(i)
print(a)
"When Method 2 is only used outputs of running time for different inputs"
# Total Running time = 2.75935 seconds #n = 100
# Total Running time = 2.86332 seconds #n = 1000
# Total Running time = 4.59884 seconds #n = 10000
# Total Running time = 8.55057 seconds #n = 100000
if __name__ == "__main__" :
n = int(input())
Prime_under_num(n)
print("Total Running time = {:.5f} seconds".format(time.time() - start_time))
上述所有情况下获得的不同运行时间都是错误的。对于我们正在接受输入的问题,我们必须在接受输入后才开始计时。这里,用户键入输入所花费的时间也与运行时间一起计算。
正确的方法
我们必须从开头删除start_time=time.time()并将其添加到主块中。
if __name__ == "__main__" :
n = int(input())
start_time = time.time()
Prime_under_num(n)
print("Total Running time = {:.3f} seconds".format(time.time() - start_time))
因此,两种方法单独使用时的输出如下:-
# Method 1
# Total Running time = 0.00159 seconds #n = 100
# Total Running time = 0.00506 seconds #n = 1000
# Total Running time = 0.22987 seconds #n = 10000
# Total Running time = 18.55819 seconds #n = 100000
# Method 2
# Total Running time = 0.00011 seconds #n = 100
# Total Running time = 0.00118 seconds #n = 1000
# Total Running time = 0.00302 seconds #n = 10000
# Total Running time = 0.01450 seconds #n = 100000
现在我们可以看到,与错误方法相比,总运行时间有显著差异。即使方法2在两种方法中的性能优于方法1,但第一种方法(错误方法)是错误的。