time.process_time() function in Python

time.process_time() function always returns the float value of time in seconds. Return the value (in fractional seconds) of the sum of the system and user CPU time of the current process. It does not include time elapsed during sleep. The reference point of the returned value is undefined, so that only the difference between the results of consecutive calls is valid.

As time module provides various time-related functions. So it is necessary to import the time module otherwise it will through error because of the definition of time.process_time() is present in time module.

Example: Understand the usage of the process_time().

# Python program to show time by process_time()
from time import process_time

# assigning n = 50
n = 50

# Start the stopwatch / counter
t1_start = process_time()

for i in range(n):
    print(i, end =' ')

print()

# Stop the stopwatch / counter
t1_stop = process_time()

print("Elapsed time:", t1_stop, t1_start)

print("Elapsed time during the whole program in seconds:",
                                         t1_stop-t1_start)

Output:

process_time_ns():
It always gives the integer value of time in nanoseconds. Similar to process_time() but return time as nanoseconds.This is only the basic difference.

Example: Understand the usage of the process_time_ns().

# Python program to show time by process_time_ns()
from time import process_time_ns

n = 50

# Start the stopwatch / counter
t1_start = process_time_ns()

for i in range(n):
    print(i, end =' ')

print()

# Stop the stopwatch / counter
t1_stop = process_time_ns()

print("Elapsed time:", t1_stop, t1_start)

print("Elapsed time during the whole program in nanoseconds:",
                                            t1_stop-t1_start)

Output:

Note: process_time() is very different from pref_counter(), as perf_counter() calculates the program time with sleep time and if any interrupt is there but process_counter only calculates the system and the CPU time during the process it not includes the sleep time.

Advantages of process_time() :
1. process_time() provides the system and user CPU time of the current process.
2. We can calculate float and integer both values of time in seconds and nanoseconds.
3. Used whenever there is a need to calculate the time taken by the CPU for the particular process.