>>> def f (x): return x**2
... 
>>> print f(8)
64
>>> 
>>> g = lambda x: x**2
>>> 
>>> print g(8)
64

>>> foo = [2, 18, 9, 22, 17, 24, 8, 12, 27]
>>> 
>>> print filter(lambda x: x % 3 == 0, foo)
[18, 9, 24, 12, 27]
>>> 
>>> print map(lambda x: x * 2 + 10, foo)
[14, 46, 28, 54, 44, 58, 26, 34, 64]
>>> 
>>> print reduce(lambda x, y: x + y, foo)
139