How to read a file in python line by line. This method incrementally loads the file.

py_read_file.py

#!/usr/bin/env python

#import pprint
#pp = pprint.PrettyPrinter(indent=4, width=110).pprint

with open('all_messages.log') as f:
    for i, line in enumerate(f):
        print("{0}:".format(i), end='')
        print(line)