gistfile1.py

import sys
import subprocess

class Pager(object):
    """enable paging for multiple writes"""
    
    def __init__(self):
        self.proc = None
        
        if hasattr(sys.stdout, 'isatty') and sys.stdout.isatty():
            pager = 'morelli -EMR' # wrong command, on purpose
            # pager = 'more -EMR'
            self.proc = subprocess.Popen([pager], shell=True, 
                stdin=subprocess.PIPE, stderr=subprocess.PIPE)
            self.file = self.proc.stdin
        else:
            self.file = sys.stdout

    def write(self, text=""):
        try:
            self.file.write("%s\n" % text)
        except:
            # in case the pager is not available on the system, for example
            self.file = sys.stdout
            self.write(text)
        
    def close(self): 
        if self.proc: 
            self.file.close() 
            self.proc.wait()
            
if __name__ == '__main__':
    printer = Pager()
    printer.write("this is the header")
    printer.write("this is the first line")
    printer.write("this is the body")
    printer.close()