def add(x, y):
    """This adds two values
    >>> add(2, 4)
    6
    """
    return x + y

add?
add??
help(add)

# Tuple - Return multiple items from a function
def roots(val):
    return (val**.5, -(val**.5))

# Lambda - One-line anonymous function
def adder(x, y):
    """This adds two values
    >>> add(2, 4)
    6
    """
    return x + y

adder2 = lambda x, y: x + y
adder(42, 10) == adder2(42, 10)

# Lambdas in sorting
names = ['john', 'paul', 'george', 'ringo']
sorted(names, key=lambda name: len(name))