Pandas Pivot错误“例外:数据必须为一维". [英] Pandas Pivot Error "Exception: Data must be 1-dimensional"

问题描述

我正在使用Pycharm(版本2018.2.4)，并在其上运行Python 3.6.7.

I am using Pycharm (version 2018.2.4) with Python 3.6.7 running on it.

我目前尝试使用pandas枢纽功能，但甚至使用示例代码:

I currently try to use the pandas pivot function, but even the sample code:

import pandas as pd
df = pd.DataFrame({'foo':['one', 'one', 'one', 'two', 'two','two'],'bar': 
  ['A', 'B', 'C', 'A', 'B', 'C'],'baz': [1, 2, 3, 4, 5, 6],'zoo': ['x', 
   'y', 'z', 'q', 'w', 't']})
df.pivot(index='foo', columns='bar', values=['baz', 'zoo'])

导致错误: 例外:数据必须是一维的

只有当我将一列列传递给values参数时，这种情况才会出现，但是该示例直接来自函数帮助: https://pandas.pydata.org/pandas- docs/stable/generated/pandas.DataFrame.pivot.html

This is only the case when I pass a list of columns to the values parameter, however this example is taken straight from the function help: https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.pivot.html

它过去曾经为我工作，但本周已停止工作，不知道为什么.我的熊猫版本是0.23.4，numpy版本是1.15.4.

It used to work for me in the past and has stopped working this week, not sure why. My pandas version is 0.23.4 and numpy version is 1.15.4.

有人知道导致此问题/如何解决此问题的原因吗?

Does anybody know what is causing this/how to fix it?

谢谢！

推荐答案

在jupyter笔记本中进行测试时，我能够重新创建相同的错误， 熊猫:0.22.0和numpy:1.14.0.

I was able to recreate the same error when testing in jupyter notebook with pandas: 0.22.0 and numpy: 1.14.0.

我无法弄清楚为什么会发生此问题，但我将示例中的代码重写为

I wasn't able to figure out why this issue happens but I rewrote the code in the example as

import pandas as pd
df = pd.DataFrame({'foo': ['one', 'one', 'one', 'two', 'two',
                          'two'],
                  'bar': ['A', 'B', 'C', 'A', 'B', 'C'],
                   'baz': [1, 2, 3, 4, 5, 6],
                   'zoo': ['x', 'y', 'z', 'q', 'w', 't']})

df.set_index(['foo','bar'],inplace=True)
df.unstack(level=1)

并获得了预期的输出(如熊猫文档)

and got the expected output (as seen in the pandas doc )

希望这会有所帮助！

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