小型带有充分索引的 Series

In [28]: obj = pd.Series(range(5), index=['a', 'a', 'b', 'b', 'c'])

In [29]: obj
Out[29]:
a    0
a    1
b    2
b    3
c    4
dtype: int64

is_unique 属性告诉标签是否唯一

In [30]: obj.index.is_unique
Out[30]: False

In [31]: obj['a']
Out[31]:
a    0
a    1

DataFrame 中进行行索引

In [34]: df = pd.DataFrame(np.random.randn(4, 3), index=['a', 'a', 'b', 'b'])

In [35]: df
Out[35]:
          0         1         2
a -1.174945  0.611333  2.096039
a -0.670033 -0.741968 -0.111807
b  1.086684 -0.608576  0.829530
b -0.532987 -0.794953  0.781699

In [36]: df.loc['b']
Out[36]:
          0         1         2
b  1.086684 -0.608576  0.829530
b -0.532987 -0.794953  0.781699