Python的print语句后跟sleep（…）函数提供了意外的输出

Question

Here's my Python 3 code:

from time import sleep
s='what is your name'
for x in s:
    print(x,end='')
    sleep(1)

What I expect is that, each letter will be printed one by one after a delay of one second. But when I run this program, it takes a time of len(s) seconds and then prints the value of s . Can anyone explain to me what is actually happening.

Answer 1

Use flush argument to print function:

print(x, end='', flush=True)

From docs :

Whether output is buffered is usually determined by file, but if the flush keyword argument is true, the stream is forcibly flushed.