1、拆箱

>>> a, b, c = 1, 2, 3
>>> a, b, c
(1, 2, 3)
>>> a, b, c = [1, 2, 3]
>>> a, b, c
(1, 2, 3)
>>> a, b, c = (2 * i + 1 for i in range(3))
>>> a, b, c
(1, 3, 5)
>>> a, (b, c), d = [1, (2, 3), 4]
>>> a
1
>>> b
2
>>> c
3
>>> d
4

2、使用拆箱进行变量交换

>>> a, b = 1, 2
>>> a, b = b, a
>>> a, b
(2, 1)

3、扩展的拆箱(Python 3支持)

>>> a, *b, c = [1, 2, 3, 4, 5]
>>> a
1
>>> b
[2, 3, 4]
>>> c
5

4、负数索引

>>> a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>>> a[-1]
10
>>> a[-3]
8

5、列表切片(a[start:end])

>>> a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>>> a[2:8]
[2, 3, 4, 5, 6, 7]

6、负数索引的列表切片

>>> a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>>> a[-4:-2]
[7, 8]

7、带步数的列表切片(a[start:end:step])

>>> a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>>> a[::2]
[0, 2, 4, 6, 8, 10]
>>> a[::3]
[0, 3, 6, 9]
>>> a[2:8:2]
[2, 4, 6]

8、负数步数的列表切片

>>> a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>>> a[::-1]
[10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
>>> a[::-2]
[10, 8, 6, 4, 2, 0]

9、列表切片赋值

>>> a = [1, 2, 3, 4, 5]
>>> a[2:3] = [0, 0]
>>> a
[1, 2, 0, 0, 4, 5]
>>> a[1:1] = [8, 9]
>>> a
[1, 8, 9, 2, 0, 0, 4, 5]
>>> a[1:-1] = []
>>> a
[1, 5]

10、切片命名(slice(start, end, step))

>>> a = [0, 1, 2, 3, 4, 5]
>>> LASTTHREE = slice(-3, None)
>>> LASTTHREE
slice(-3, None, None)
>>> a[LASTTHREE]
[3, 4, 5]

11、遍历列表索引和值(enumerate)

>>> a = ["Hello", "world", "!"]
>>> for i, x in enumerate(a):
... print "{}: {}".format(i, x)
...
0: Hello
1: world
2: !

12、遍历字典的KEY和VALUE(dict.iteritems)

>>> m = {"a": 1, "b": 2, "c": 3, "d": 4}
>>> for k, v in m.iteritems():
... print "{}: {}".format(k, v)
...
a: 1
c: 3
b: 2
d: 4
 
# 注意：Python 3中要使用dict.items

13、压缩 & 解压列表和可遍历对象

>>> a = [1, 2, 3]
>>> b = ["a", "b", "c"]
>>> z = zip(a, b)
>>> z
[(1, "a"), (2, "b"), (3, "c")]
>>> zip(*z)
[(1, 2, 3), ("a", "b", "c")]

14、使用zip分组相邻列表项

>>> a = [1, 2, 3, 4, 5, 6]
 
>>> # Using iterators
>>> group_adjacent = lambda a, k: zip(*([iter(a)] * k))
>>> group_adjacent(a, 3)
[(1, 2, 3), (4, 5, 6)]
>>> group_adjacent(a, 2)
[(1, 2), (3, 4), (5, 6)]
>>> group_adjacent(a, 1)
[(1,), (2,), (3,), (4,), (5,), (6,)]
 
 
>>> # Using slices
>>> from itertools import islice
>>> group_adjacent = lambda a, k: zip(*(islice(a, i, None, k) for i in range(k)))
>>> group_adjacent(a, 3)
[(1, 2, 3), (4, 5, 6)]
>>> group_adjacent(a, 2)
[(1, 2), (3, 4), (5, 6)]
>>> group_adjacent(a, 1)
[(1,), (2,), (3,), (4,), (5,), (6,)]