"""
 b2.py

 second version of happy birthday song.

 Print only in main.
 Other functions have clean args and return values.

"""

def double(x):
    return 2*x

def birthday(name):
    return """Happy birthday to you,
happy birthday to you,
happy birthday dear {},
happy birthday to you!""".format(name)

def main():
    song = birthday('Sally')
    print(song)

main()