Python中的循环技术

>>> x = [1, 2, 3, ‘p‘ , ‘y‘]
>>> for v in x:
...     print(x)
...
1
2
3
p
y

>>> y = {‘a‘:11, ‘b‘:22}
>>> y
{‘b‘: 22, ‘a‘: 11}
>>> for v in y:
...     print(v)
...
b
a
>>> for v in y.keys():
...     print(v)
...
b
a
>>> for v in y.values():
...     print(v)
...
22
11
>>> for v in y.items():
...     print(v)
...
(‘b‘, 22)
(‘a‘, 11)

>>> x
[1, 2, 3]
>>> y
{‘c‘, ‘b‘, ‘a‘}
>>> for i, j in zip(x, y):  # 用i,j分别遍历容器x和y中的元素，一旦其中某个容器遍历结束循环终止。
...     print(i, j)
...
1 c
2 b
3 a

>>> z = (5, 6, 7)
>>> for i,j,k in zip(x,y,z):     # 同时遍历三个容器
...     print(i, j, k)
...
1 c 5
2 b 6
3 a 7

获取 1-10的逆序序列
>>> for i in reversed(range(10)):
...     print(i+1, end = ‘ ‘)
...
10 9 8 7 6 5 4 3 2 1

获取有序的字符序列
>>> for c in sorted(‘hello world‘):
...     print(c, end = ‘ ‘)
...
  d e h l l l o o r w

去除重复数据
>>> for x in set([1,1,2,2,2,3,3]):
...     print(x, end = ‘ ‘)
...
1 2 3

>>> word = [‘a‘, ‘b‘, ‘c‘]
>>> for v in word[:]:
...     word.append(‘q‘)
...
>>> word

[‘a‘, ‘b‘, ‘c‘, ‘q‘, ‘q‘, ‘q‘]

参考：

[1] Python3.4 帮助文档 https://docs.python.org/3/tutorial/datastructures.html#tuples-and-sequences

Python中的循环技术,布布扣,bubuko.com

Python中的循环技术

原文：http://blog.csdn.net/xiaohui_hubei/article/details/25060421