Why default datetime is not changing in python?

Question

Below is my code. Here, get_time() is returning the same value even after 5 secs, why is that so?

from datetime import datetime

import time


def get_time(time_now=datetime.now()):
    print('Current time', time_now)


get_time()
time.sleep(5)
get_time()

Answer 1

Python’s default arguments are evaluated once when the function is defined, not each time the function is called. So if you want time_now to be evaluated in each function call then you have to do something like this,

def get_time():
    print('Current time', datetime.now())