filter.py

def is_odd(x):
    return x % 2 == 1
print filter(is_odd, [1, 4, 6, 7, 9, 12, 17])

def is_not_empty(s):
    return s and len(s.strip()) > 0
print filter(is_not_empty, ['test', None, '', 'str', '  ', 'END'])

a='\t\t123\r\n'
print a.strip()

import math
def is_sqr(x):
    return math.sqrt(x)%1==0
print filter(is_sqr, range(1, 101))

def is_not_empty(s):
    return s and len(s.strip()) > 0
print filter(is_not_empty, ['test', None, '', 'str', '  ', 'END'])

print filter(lambda s: s and len(s.strip()) > 0,['test', None, '', 'str', '  ', 'END'])