How to flush output of print function?

Question

How do I force Python\'s print function to output to the screen?

_{This is not a duplicate of Disable output buffering - the linked question is attempting unbuffe}

Answer 1

Dan's idea doesn't quite work:

#!/usr/bin/env python
class flushfile(file):
    def __init__(self, f):
        self.f = f
    def write(self, x):
        self.f.write(x)
        self.f.flush()

import sys
sys.stdout = flushfile(sys.stdout)

print "foo"

The result:

Traceback (most recent call last):
  File "./passpersist.py", line 12, in 
    print "foo"
ValueError: I/O operation on closed file

I believe the problem is that it inherits from the file class, which actually isn't necessary. According to the docs for sys.stdout:

stdout and stderr needn’t be built-in file objects: any object is acceptable as long as it has a write() method that takes a string argument.

so changing

class flushfile(file):

to

class flushfile(object):

makes it work just fine.