Python 3 打印时清除线条

Question

I am trying to clear a line for a loading element, I have the printing-on-one-line part of it, I just need this

I have consulted some websites(mainly this one) and I cannot find an answer, I am using https://trinket.io as my coder, I also have python from https://python.org , can you find code that works?

Here is the code I have so far:

import functools

printf = functools.partial(print, end="")

loading():
    printf("loading")
    printf(".")
    time.sleep(.3)
    printf(".")
    time.sleep(.3)
    printf(".")
    time.sleep(.3)
    printf(".")
    time.sleep(.3)
    printf(".")

Which gives me this output(final stage):

loading.....

I want to delete the line above so I can use the loading sequence multiple times.

Answer 1

I believe these adjustments will get what you want:

import functools
import time

printf = functools.partial(print, end="", flush=True)

def loading():
    printf("\r{:12}\r".format(''))
    printf("loading")
    printf(".")
    time.sleep(.3)
    printf(".")
    time.sleep(.3)
    printf(".")
    time.sleep(.3)
    printf(".")
    time.sleep(.3)
    printf(".")

loading()
time.sleep(2)
loading()

Two changes:

1. Setting flush=True in print makes sure that each dot prints between sleep statements, otherwise they'll all be displayed at once.
2. printf("\r{:12}\r".format('')) clears the line. '\r' is carriage return, moving cursor to beginning, then it prints some blank spaces to "clear" (overwrite) the loading text (which is 12 characters), and then does carriage return again to print a new loading message.