# Reading a file

f = open('test_file.txt', 'r')

line = None

while line != "":
    line = f.readline()
    print line

f.close()

# Reading a file with for loop

f = open('test_file.txt', 'r')

for line in f:
    print f

f.close()

# Reading a file with 'with'

with open('test_file.txt', 'r') as f:
    for line in f:
        print f

    # 'with' syntax automatically closes file after block ends