For my Python tutorial "Count the number of lines in a file" (http://wp.me/p1V5ge-1BK)

countfilelines.py

#! /usr/bin/env/python
# -*- coding: utf-8 -*-

from __future__ import print_function

numOfLines = 0

with open("samplefile.txt", "rt") as f:
    for line in f:
        numOfLines += 1

print("There are {0} lines in this file.".format(numOfLines))

samplefile.txt

This is the first line.
This is the second line.
Three is a magic number. Yes it is. It's a magic number.
Fishing Four Fish
Fives are easy to count by.
I got six! That's all there is!
Too bad there is no line 0. My Hero Zero is catchier than Lucky Number 7.