popen.py

#!/usr/bin/env python3
# @file: popen.py
# @auth: sprax
# @date: 2020-04-01 13:35:50 Wed 01 Apr

import errno
from subprocess import PIPE, Popen

p = Popen('less', text=True,
          stdin=PIPE)

for x in range(100):
    line = 'Line number %d.\n' % x
    try:
        p.stdin.write(line)

    except IOError as e:
        if e.errno == errno.EPIPE or e.errno == errno.EINVAL:
            # Stop loop on "Invalid pipe" or "Invalid argument".
            # No sense in continuing with broken pipe.
            break
        else:
            # Raise any other error.
            raise

p.stdin.close()
p.wait()

# This should always be printed below any output written to less.
print('All done!')