Why doesn't `print`ed output on the same line appear between `time.sleep` calls?

Question

So I'm having some trouble with Python. I have a code that is:

import time

def printChat(string, sleepTime):
    for a in string:
        print (a, end="")
        time.sleep(sleepTime)
    print()

When I do printChat("Hello", 0.1) it should print a letter and wait 0.1 seconds and then print the next one, but instead, it waits 0.5 seconds (as 'hello' is 5 characters long) and then prints hello all of a sudden. Any idea why that is?

See [How to flush output of Python print?](https://stackoverflow.com/q/230751/35070). — phihag, Mar 18 '18 at 17:09
Possible duplicate of [How to flush output of Python print?](https://stackoverflow.com/questions/230751/how-to-flush-output-of-python-print) — Joe Iddon, Mar 18 '18 at 17:10

score 6 · Accepted Answer · answered Mar 18 '18 at 17:09

6

You should use:

        print (a, end="", flush=True)

Because console output is line-buffered.

answered Mar 18 '18 at 17:09

llllllllll

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Can you provide a source to the statement that console output is buffered? Isn't it stdout that's a buffered stream, no matter whether it goes to console or file? – phihag Mar 18 '18 at 17:11
@phihag If it's a file, then `'\n'` won't flush the buffer. Only console is line-buffered. – llllllllll Mar 18 '18 at 17:12
Thanks, it is now working fine. I'll accept the answer as soon as I can. – WhoKnows Mar 18 '18 at 17:15

Why doesn't `print`ed output on the same line appear between `time.sleep` calls?

1 Answers1

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