In my python code having:
print "Hello" time.sleep(20) print "world" I am expecting output as
Hello and then after 20 seconds
world But Hello and world are printing simultaneously in the console.
3 Answers
print operator effectively uses sys.stdout stream for output which is buffered. For real-time output you'll want to use sys.stderr stream which is not buffered:
import sys, time sys.stderr.write("Hello ") time.sleep(20) sys.stderr.write("world\n") Alternatively, you can flush stream buffer manually by calling sys.stdout.flush() each time you want to get output but I suggest you not to do it in such way unless you know what you're doing.
For more details there is an article in Wikipedia on standard streams (stdin, stdout and stderr).
Comments
Your code works in my computer. You can try to flush the stdout directly after printing hello
import sys sys.stdout.flush() 
1 Comment
gmanikandan
My code has so many print commands.So I have to give "sys.stdout.flush()" after every print command.Is there any other way ??
Make sure you've imported the time library from python, and try it on both versions of python to see if you can experience the same error. I've tried it on my end and it works.
1 Comment
Jessie
It would throw an error when trying to run
time.sleep() if it was not imported.
import), and verify that that example reproduces the issue.time.sleep(20)with aNameError? I don't think that's the problem.