Python中的推导式

1.列表推导式

In [1]: [i**2 for i in range(1,5)]
Out[1]: [1, 4, 9, 16]

2.字典推导式

In [2]: {i:i**2 for i in range(1,5)}
Out[2]: {1: 1, 2: 4, 3: 9, 4: 16}

3.集合推导式

In [3]: { i for i in range(1,5)}
Out[3]: {1, 2, 3, 4}

4.生成器推导式

In [11]: items = (i**2 for i in range(1,5))

In [12]: for item in items:
    ...:     print(item)
    ...:
1
4
9
16