python - 自然排序pandas数据出现错误

Question

我有一个带有以下索引的 pandas 数据

print(df.index)
MultiIndex(levels=[[u'Day 3', u'Day 4', u'Day 5', u'Day 7', u'Day 9'], [u'D1', u'D10', u'D11', u'D12', u'D2', u'D3', u'D4', u'D5', u'D6', u'D7', u'D8', u'D9'], [1.0, 2.0, 3.0]],
       labels=[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 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, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4], [0, 0, 0, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 10, 11, 11, 11, 1, 1, 1, 2, 2, 2, 3, 3, 3, 0, 0, 0, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 10, 11, 11, 11, 1, 1, 1, 2, 2, 2, 3, 3, 3, 0, 0, 0, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 10, 11, 11, 11, 1, 1, 1, 2, 2, 2, 3, 3, 3, 0, 0, 0, 4, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 10, 11, 11, 11, 1, 1, 1, 2, 2, 2, 3, 3, 3, 0, 0, 0, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 10, 11, 11, 11, 1, 1, 1, 2, 2, 2, 3, 3, 3], [1, 2, 0, 1, 2, 0, 0, 2, 1, 0, 1, 2, 2, 0, 1, 0, 2, 1, 1, 2, 0, 1, 0, 2, 2, 0, 1, 0, 1, 2, 2, 1, 0, 1, 2, 0, 0, 2, 1, 0, 2, 1, 2, 0, 1, 0, 2, 1, 1, 0, 2, 0, 1, 2, 0, 2, 1, 2, 0, 1, 0, 2, 1, 0, 2, 1, 2, 0, 1, 0, 2, 1, 2, 1, 0, 0, 2, 1, 1, 2, 0, 0, 2, 1, 0, 1, 2, 0, 1, 2, 2, 1, 0, 1, 0, 2, 1, 0, 2, 0, 1, 2, 2, 0, 1, 1, 0, 2, 1, 2, 0, 1, 1, 2, 0, 2, 1, 0, 1, 2, 0, 0, 1, 2, 0, 1, 2, 2, 1, 0, 1, 0, 2, 2, 0, 1, 0, 1, 2, 0, 2, 1, 2, 0, 1, 1, 2, 0, 0, 2, 1, 0, 2, 1, 0, 2, 1, 2, 1, 0, 0, 2, 1, 2, 0, 1, 2, 0, 1, 2, 1, 0, 1, 2, 0, 2, 1, 0, 1, 2, 0]],
       names=[u'Interval', u'Device', u'Well'])

我正在使用以下内容进行排序

 df = df.reindex(index=natsorted(df.index))

但是，对于这个特定的 df，它会返回以下错误。

raise Exception("cannot handle a non-unique multi-index!")
Exception: cannot handle a non-unique multi-index!

任何帮助将不胜感激。

Answer 1

我做了一个最小的例子，可以重现您的错误。看来这种情况确实发生了，因为 arrays 中的 Day 3、D1 和 1.0 具有相同的级别元组。如果删除其中之一，它就可以正常工作。

import pandas as pd
import numpy as np
from natsort import natsorted

arrays = [[u'Day 3', u'Day 3', u'Day 4', u'Day 5', u'Day 7', u'Day 9', u'Day 3', u'Day 4', u'Day 5', u'Day 7', u'Day 9'],
          [u'D1',    u'D1',    u'D10',   u'D11',   u'D12',   u'D2',    u'D3',    u'D4',    u'D5',    u'D6',    u'D7'],
          [1.0,      1.0,      2.0,      3.0,      1.0,      2.0,      1.0,      2.0,      3.0,      1.0,      2.0]]
tuples = list(zip(*arrays))
index = pd.MultiIndex.from_tuples(tuples, names=[u'Interval', u'Device', u'Well'])
df = pd.Series(np.random.randn(len(arrays[0])), index=index)

print df.index

df = df.reindex(index=natsorted(df.index))

正如您提到的，您使用多个 Excel 文件，这可能会有所帮助:Merging multiple dataframes with non unique indexes