Built-in functions: zip, filter, map, stored

zip: a plurality iterables, from the beginning, one returns a tuple

a = ('a','b','c ','c')
b = ('a','b','c','c')
ret = zip(a,b)
for i in ret:
    print(i)
print(list(zip(a,b)))

#打印
('a', 'a')
('b', 'b')
('c ', 'c')
('c', 'c')
[('a', 'a'), ('b', 'b'), ('c ', 'c'), ('c', 'c')]

 filter: filter, to filter out ineligible elements, return an iterator object consists of qualified elements. 
The receiving two parameters, as a function of a first, a second sequence, each element of the sequence as an argument to a function to judge, then return True or False, and finally returns True elements into the new object

l = [1,2,3,-1,-5,0,51]
func = filter(lambda x : x > 0,l)
for i in func:
    print(i)

#打印：
1
2
3
51

 

map: map () function accepts two arguments, a function, a sequence is, in turn a function of the incoming effect to each element of the sequence, and the result as a new object l return, Map () is the iterator .

l = [1,2,3,-1,-5,0,51]
func = map(lambda x : x + 1,l)
for i in func:
    print(i)

#打印
2
3
4
0
-4
1
52

 

sorted: sorting, and a list of built-in methods different sort, sorted sort all iterables, is to create a sort of memory, it will not affect the original list

= L [l, 2,3, -1, -5,0,51 ] 
info_sort = the sorted (L, Key = ABS)
 Print (info_sort) 

# Printing: 
[0, 1, -1, 2, 3, -5 , 51]