Python-内置函数小结

a=‘213‘
isinstance(a,str)
返回True

eval(‘1+2‘) 返回3
eval("[1,2,3]") 返回[1,2,3]

def even(n):
　　if n % 2 == 0:
　　　　return True
filter(even,xrange(10))
[0, 2, 4, 6, 8]

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

l1 = [1, 2, 3]
l2 = [‘a‘, ‘b‘, ‘c‘, ‘d‘]
l3 = [‘I‘, ‘II‘, ‘III‘, ‘IV‘, ‘V‘, ‘VI‘]
map(None,l1,l2,l3)
[(1, ‘a‘, ‘I‘),
(2, ‘b‘, ‘II‘),
(3, ‘c‘, ‘III‘),
(None, ‘d‘, ‘IV‘),
(None, None, ‘V‘),
(None, None, ‘VI‘)]

map(lambda x,y:x+y,l1,l4)