Paging output from python

It is a good idea to be explicit in your code, so that it shows that you use a special print function printc() instead of the standard one. Using subprocess.call() is also sufficient (you don't need the pipe machinery). Furthermore, you can save a variable by not storing the name of the temporary file:

from __future__ import print_function

import subprocess, tempfile

page = True  # For tests

# Definition of a printc() function that prints to the correct output
if page:
    tmp_file = open(tempfile.mkstemp()[1], 'w')  # No need to store the name in a specific variable
    def printc(*largs, **kwargs):
        if 'file' not in kwargs:  # The code can still use the usual file argument of print()
            kwargs['file'] = tmp_file  # Forces the output to go to the temp file
        print(*largs, **kwargs)
else:
    printc = print  # Regular print

# Main program:

printc('...some text...', 'some more text', sep='/')  # Python3 syntax

# Paging of the current contents of the temp file:
if page:
    tmp_file.flush()  # No need to close the file: you can keep printing to it
    subprocess.call(['less', tmp_file.name])  # Simpler than a full Popen()

This way, you get the flexibility of Python 3's print function, with a code that explicitly shows that you're doing some fancy printing stuff. This scales better with larger programs than modifying the "global" sys.stdout variable in some locations of your code.

How about this:

import pydoc
text = '... some text ... '
pydoc.pager(text)

This (on my opensuse linux box) sends the text to a pager ('less' in my case), and works the same as calling "help(... python command...)" within the Python interpreter.

Use subprocess.Popen instead.

http://docs.python.org/library/subprocess.html#subprocess-replacements

http://docs.python.org/library/subprocess.html#subprocess.Popen

There is even a note about this in the os.popen docs.

http://docs.python.org/library/os.html#os.popen