print without new line only appear after I write something else

Question

I'm using Python 2.7.3 and I running the code below

def t2():
    print "Waiting...",
    time.sleep(3)
    print "done."
    time.sleep(1)
    print "test"
    time.sleep(2)
    print "testing"

When I run this code, the string "Waiting... done." appear at same time. It's like the sleep(2) is before the first print.

If I don't use comma to remove new line (Like "test" and "testing" examples), sleep function works ok but I get "Waiting..." and "done." on different lines.

I already tried:

for i in range(0, 5): time.sleep(1)

and

subprocess.check_output(["sleep", "5"])

What can I do?

Thank you.

that's pretty standard for many environments - they don't actually display a buffered string until a newline is added to the buffer. Add a flush() (or whatever python's equivalent is) before each sleep call. — Marc B, Dec 17 '14 at 21:16
Try calling `sys.stdout.flush()`. Don't forget to `import sys` — inspectorG4dget, Dec 17 '14 at 21:17
Interesting. For me, it works just fine. Which platform do you use (Win7/8, OSX, Linux Distro)? — Dave J, Dec 17 '14 at 21:32

score 0 · Accepted Answer · edited May 23 '17 at 12:28

0

Depending what you are working with data doesn't necessarily get written right away. In particular, display output often waits until it receives a newline before printing anything.

flush() makes sure it all gets written right now.

Background reading that helps explain better than I can: Usage of sys.stdout.flush() method

edited May 23 '17 at 12:28

Community

1
1

answered Dec 17 '14 at 22:43

luftwaffles

16
2

print without new line only appear after I write something else

1 Answers1