pandas多索引set_labels

Question

我有一个像这样的熊猫多索引

result.index

MultiIndex(levels=[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35], [1, 6, 12, 17, 18, 21, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 66, 67, 70, 71, 72, 73, 74]],
           labels=[[10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14], [17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27]],
           names=['ref', None])

我想把第二个标签换成这个

new_label
[-0.9, -0.85, -0.8, -0.75, -0.7, -0.65, -0.6, -0.55, -0.5, -0.45, -0.4, -0.9, -0.85, -0.8, -0.75, -0.7, -0.65, -0.6, -0.55, -0.5, -0.45, -0.4, -0.9, -0.85, -0.8, -0.75, -0.7, -0.65, -0.6, -0.55, -0.5, -0.45, -0.4, -0.9, -0.85, -0.8, -0.75, -0.7, -0.65, -0.6, -0.55, -0.5, -0.45, -0.4, -0.9, -0.85, -0.8, -0.75, -0.7, -0.65, -0.6, -0.55, -0.5, -0.45, -0.4]

所以结果应该是

result.index

    MultiIndex(levels=[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35], [1, 6, 12, 17, 18, 21, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 66, 67, 70, 71, 72, 73, 74]],
               labels=[[10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14], [-0.9, -0.85, -0.8, -0.75, -0.7, -0.65, -0.6, -0.55, -0.5, -0.45, -0.4, -0.9, -0.85, -0.8, -0.75, -0.7, -0.65, -0.6, -0.55, -0.5, -0.45, -0.4, -0.9, -0.85, -0.8, -0.75, -0.7, -0.65, -0.6, -0.55, -0.5, -0.45, -0.4, -0.9, -0.85, -0.8, -0.75, -0.7, -0.65, -0.6, -0.55, -0.5, -0.45, -0.4, -0.9, -0.85, -0.8, -0.75, -0.7, -0.65, -0.6, -0.55, -0.5, -0.45, -0.4]],
               names=['ref', None])

我试着用

result.index.set_labels(labels=new_label,level=1)

但我得到的却是这个

MultiIndex(levels=[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35], [1, 6, 12, 17, 18, 21, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 66, 67, 70, 71, 72, 73, 74]],
           labels=[[10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]],
           names=['wnd dir ref', None])

标签用0填充

哪里出了问题或遗漏了什么？

Answer 1

如果想使用set_label需要相同类型，这里是整数(似乎是bug)：

#test if working with integers
mux1 = mux.set_labels((np.array(new_label) * 100).astype(int), level=1)
print (mux1)

MultiIndex(levels=[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35], [1, 6, 12, 17, 18, 21, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 66, 67, 70, 71, 72, 73, 74]],
           labels=[[10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14], [-90, -85, -80, -75, -70, -65, -60, -55, -50, -45, -40, -90, -85, -80, -75, -70, -65, -60, -55, -50, -45, -40, -90, -85, -80, -75, -70, -65, -60, -55, -50, -45, -40, -90, -85, -80, -75, -70, -65, -60, -55, -50, -45, -40, -90, -85, -80, -75, -70, -65, -60, -55, -50, -45, -40]],
           names=['ref', None])

mux = pd.MultiIndex(levels=[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35], [1, 6, 12, 17, 18, 21, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 66, 67, 70, 71, 72, 73, 74]],
           labels=[[10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14], [17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27]],
           names=['ref', None])

df = pd.DataFrame([0] * 55, index=mux, columns=['a'])

可能的解决方案是对新的3级MultiIndex使用set_index，并通过reset_index删除第二个

df = df.set_index([new_label], append=True).reset_index(level=1, drop=True)

或创建新的MultiIndex：

df.index = [df.index.get_level_values(0), new_label]
print (df.head(10))
           a
ref         
10  -0.90  0
    -0.85  0
    -0.80  0
    -0.75  0
    -0.70  0
    -0.65  0
    -0.60  0
    -0.55  0
    -0.50  0
    -0.45  0

另外，如果需要设置MultiIndex名称：

df.index = pd.MultiIndex.from_arrays([df.index.get_level_values(0), 
                                      new_label], names=('ref','new'))
print (df.head(10))
           a
ref new     
10  -0.90  0
    -0.85  0
    -0.80  0
    -0.75  0
    -0.70  0
    -0.65  0
    -0.60  0
    -0.55  0
    -0.50  0
    -0.45  0