Print Reload achieved using sys.stdout.write

Man of few words said on the first piece of code

import time
from datetime import datetime as dt

for i in range(5):
    print(dt.now())
    time.sleep(1)

The output is:

2019-07-31 11:40:00.334841
2019-07-31 11:40:01.335235
2019-07-31 11:40:02.335700
2019-07-31 11:40:03.335846
2019-07-31 11:40:04.336174

Visible print a message each time another will be played under a line of print, this is why?

Let's execute code help (print) statement to get the following information

Help on built-in function print in module builtins:

print(...)
    print(value, ..., sep=' ', end='\n', file=sys.stdout, flush=False)
    
    Prints the values to a stream, or to sys.stdout by default.
    Optional keyword arguments:
    file:  a file-like object (stream); defaults to the current sys.stdout.
    sep:   string inserted between values, default a space.
    end:   string appended after the last value, default a newline.
    flush: whether to forcibly flush the stream.

Visible each time the print function, the end will perform a line feed. If we want every new time information output at the same time covering the original information how to do it?

Then we can use sys.stdout.write function:

import time
from datetime import datetime as dt
import sys

while True:
    sys.stdout.write('\r{0}'.format(dt.now()))
    sys.stdout.flush()
    time.sleep(1)

effect:

2019-07-31 13:45:15.537898

A time line will update every second