Python| time.process_time_ns() 方法

Python中的时间模块提供了各种与时间相关的功能。该模块属于 Python 的标准实用程序模块。

Python中time 模块的time.process_time_ns()方法用于获取当前进程的系统和用户 CPU 时间的总和，以纳秒为单位。此方法不包括睡眠期间经过的时间。此方法类似于time.process_time()方法，它以小数秒为单位返回当前进程的系统和用户 CPU 时间的总和。

由于单调时钟返回值的参考点未定义，因此只有连续调用结果之间的差异才有效。

Syntax: time.process_time_ns()

Parameter: No parameter is required.

Return type: This method returns an integer value which represents the sum of the system and user CPU time of the current process in nanoseconds.

编程需要懂一点英语

代码 #1：使用time.process_time_ns()方法

# Python program to explain time.process_time_ns() method
  
# importing time module
import time
  
# assigning n = 100  
n = 100 
    
# Get the sum of the system 
# and user CPU time of
# the current process in nanoseconds
# using time.process_time_ns() method
start = time.process_time_ns()  
    
print("At the beginning of the process")
print("Process Time (in nanoseconds):", start, "\n")
# Here process time means sum of the system
# and user CPU time of the current process
    
  
# Print all natural numbers
# from 1 to 100
  
for i in range(1, n + 1): 
    print(i, end =' ') 
    
print()  
    
  
end = time.process_time_ns() 
     
print("\nAt the end of the process")
print("Process time (in nanoseconds):", end)     
print("Elapsed time during the process (in nanoseconds):", end - start)

输出：

At the beginning of the process
Process Time (in nanoseconds): 31873819

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 

At the end of the process
Process time (in nanoseconds): 32271699
Elapsed time during the whole process (in nanoseconds): 397880

代码 #2：显示time.process_time_ns()方法不包括睡眠期间经过的时间

# Python program to explain time.process_time_ns() method
  
# importing time module
import time
  
  
# Get the sum of the system 
# and user CPU time of
# the current process in nanoseconds
# using time.process_time_ns() method
start = time.process_time_ns()  
    
print("At the beginning of first example")
print("Process Time (in nanoseconds):", start, "\n")
# Here process time means sum of the system
# and user CPU time of the current process
    
# Print all natural numbers
# from 1 to 50
  
# assigning n = 50  
n = 50
    
for i in range(1, n + 1): 
    print(i, end =' ') 
      
  
print()  
  
end = time.process_time_ns()
  
print("\nAt the end of the first example")
print("Process time (in nanoseconds):", end)    
print("Elapsed time during the first example (in nanoseconds):", end-start) 
  
  
# Get the sum of the system 
# and user CPU time of
# the current process in nanoseconds
# using time.process_time_ns() method
start = time.process_time_ns()  
    
print("\nAt the beginning of second example")
print("Process Time (in nanoseconds):", start, "\n")
# Here process time means sum of the system
# and user CPU time of the current process
    
# Print all natural numbers
# from 1 to 50
  
# assigning n = 100  
n = 50
    
for i in range(1, n + 1): 
    print(i, end =' ') 
      
  
print()  
  
# suspend the execution of the current
# process for 10 seconds
time.sleep(10)
  
end = time.process_time_ns()
print("\nAt the end of the second example")
print("Process time (in nanoseconds):", end)    
print("Elapsed time during the second example (in nanoseconds):", end-start) 
  
  
  
# In both the examples 
# we can see (in the output below)
# that elapsed time 
# is more or less the same 
# so, the suspension of process for
# 10 seconds is not included

输出：

At the beginning of first example
Process Time (in nanoseconds): 26901160

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50 

At the end of the first example
Process time (in nanoseconds): 27091390
Elapsed time during the first example (in nanoseconds): 190230

At the beginning of second example
Process Time (in nanoseconds): 27186972

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50 

At the end of the second example
Process time (in nanoseconds): 27377123
Elapsed time during the second example (in nanoseconds): 190151

参考： https://docs。 Python.org/3/library/time.html#time.process_time_ns