Python functional programming

From Augix' Wiki

• A function is an object.

square = lambda x: x**2

• Functions can be returned as objects

def build_taxer(rate):
    def taxer(amount):
        return amount * (float(rate) / 100)
    return taxer

• filter and lambda

filter( lambda x: x%2==0, range(10))

• list comprehensions can replace map and filter, but compute the whole list is slow

[i**2 for i in range(10) if i%2==0]

• list is slow actually we only need to compute part of the list

def is_prime(n):
    return not any(n%k==0 for k in xrange(2,n))

• • in contrast to any(seq), all(seq) returns true if all elements of the sequence are true