bash - python stdout to file does not respond in real time -

write simple python script test.py:

  import time   print "begin"   time.sleep(10)   print "stop"

in bash, run

python test.py > log.txt

what observe both "begin" , "stop" appear in log.txt @ same time, after 10 seconds.

is expected behavior?

you need flush buffer after printing.

import sys import time  print "begin" sys.stdout.flush()  time.sleep(10)  print "end" sys.stdout.flush()

or in python 3:

# can done in python 2.6+ # __future__ import print_function  import time  print("begin", flush=true) time.sleep(10) print("end", flush=true)

Print F