Python 按值将一列拆分为两列

我有一个给定的列，其中我有5个不同的值。我需要创建新列，如下所示：

A和B都是-->col1

A和B都不去-->col1

A去B不去-->col2

A不去B去-->col2

不知道-->如果值为NaN，则两者都是

      Given_Col                    Expexted_Col1              Expexted_Col2    

Both A and B goes                 Both A and B goes               No idea
Neither A nor B goes             Neither A nor B goes             No idea
A goes B doesn't go                    No idea               A goes B doesn't go  
A doesn't go B goes                    No idea               A doesn't go B goes 
A goes B doesn't go                    No idea               A goes B doesn't go
Neither A nor B goes             Neither A nor B goes             No idea 
No idea                                No idea                    No idea 
Both A and B goes                  Both A and B goes              No idea 

我想不出任何解决办法。实际的方法是什么

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注意：我考虑过复制现有列并映射值，也许？

我认为两个条件列分配应该可以工作

每一个都会根据选择条件为列拾取有效条目。如果您有五种以上的可能性，这可能是不合适的，但对于这种情况，它应该足够有效

df['Expexted_Col1'] = df.apply(lambda x: x['Given_Col'] if (x['Given_Col'] == 'Both A and B goes' or x['Given_Col'] == 'Neither A nor B goes') else 'No idea', axis = 1)
df['Expexted_Col2'] = df.apply(lambda x: x['Given_Col'] if (x['Given_Col'] == "A goes B doesn't go" or x['Given_Col'] == "A doesn't go B goes") else 'No idea', axis = 1)

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我认为两个有条件的列分配应该有效

每一个都会根据选择条件为列拾取有效条目。如果您有五种以上的可能性，这可能是不合适的，但对于这种情况，它应该足够有效

df['Expexted_Col1'] = df.apply(lambda x: x['Given_Col'] if (x['Given_Col'] == 'Both A and B goes' or x['Given_Col'] == 'Neither A nor B goes') else 'No idea', axis = 1)
df['Expexted_Col2'] = df.apply(lambda x: x['Given_Col'] if (x['Given_Col'] == "A goes B doesn't go" or x['Given_Col'] == "A doesn't go B goes") else 'No idea', axis = 1)

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您可以使用几个np来实现这一点。其中函数：

df['col1'] = np.where(df['Given_Col'] == 'Both A and B goes', 'Both A and B goes', df['col1'])
df['col2'] = np.where(df['Given_Col'] == 'Both A and B goes', 'No idea', df['col1'])
df['col1'] = np.where(df['Given_Col'] == 'Neither A nor B goes', 'Neither A nor B goes', df['col2'])
df['col2'] = np.where(df['Given_Col'] == 'Neither A nor B goes', 'No idea', df['col2'])

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您可以从这里继续……

您可以使用几个np函数来完成此操作。其中函数：

df['col1'] = np.where(df['Given_Col'] == 'Both A and B goes', 'Both A and B goes', df['col1'])
df['col2'] = np.where(df['Given_Col'] == 'Both A and B goes', 'No idea', df['col1'])
df['col1'] = np.where(df['Given_Col'] == 'Neither A nor B goes', 'Neither A nor B goes', df['col2'])
df['col2'] = np.where(df['Given_Col'] == 'Neither A nor B goes', 'No idea', df['col2'])

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您可以从这里继续…

单向使用

pandas.DataFrame.assign

with

fillna

：

mapper = {'col1': ['Both A and B goes', 'Neither A nor B goes'],
 'col2': ["A goes B doesn't go", "A doesn't go B goes"]}

s = df["Given_Col"]
new_df = df.assign(**{k: s[s.isin(v)] for k, v in mapper.items()}).fillna("No idea")
print(new_df)

输出：

              Given_Col                  col1                 col2
0     Both A and B goes     Both A and B goes              No idea
1  Neither A nor B goes  Neither A nor B goes              No idea
2   A goes B doesn't go               No idea  A goes B doesn't go
3   A doesn't go B goes               No idea  A doesn't go B goes
4   A goes B doesn't go               No idea  A goes B doesn't go
5  Neither A nor B goes  Neither A nor B goes              No idea
6               No idea               No idea              No idea
7     Both A and B goes     Both A and B goes              No idea

---

单向使用

pandas.DataFrame.assign

和

fillna

：

mapper = {'col1': ['Both A and B goes', 'Neither A nor B goes'],
 'col2': ["A goes B doesn't go", "A doesn't go B goes"]}

s = df["Given_Col"]
new_df = df.assign(**{k: s[s.isin(v)] for k, v in mapper.items()}).fillna("No idea")
print(new_df)

输出：

              Given_Col                  col1                 col2
0     Both A and B goes     Both A and B goes              No idea
1  Neither A nor B goes  Neither A nor B goes              No idea
2   A goes B doesn't go               No idea  A goes B doesn't go
3   A doesn't go B goes               No idea  A doesn't go B goes
4   A goes B doesn't go               No idea  A goes B doesn't go
5  Neither A nor B goes  Neither A nor B goes              No idea
6               No idea               No idea              No idea
7     Both A and B goes     Both A and B goes              No idea

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映射器是从哪里来的？再进一步，我可以用你一次做的方式，将A和B都替换为1，A和B都不替换为-1，

不知道

都替换为0吗？然后你可以制作一个新的

映射器

（类似于

{col1:{“A和B都去了”：1，

），并乘以布尔数组。顺便说一句，在同一篇文章中问另一个问题从来都不是一个好主意，尤其是通过注释，因为不仅注释部分在提供正确答案方面有限制，而且也不能保证回答者知道下一部分的答案；）。映射器来自哪里？再进一步，我可以替换

A和B都变成1，
A和B都变成-1，
不知道
变成0，就像你现在做的那样？然后你会制作一个新的
映射器（类似于
{“col1”：{“A和B都变成”：1，
），并乘以布尔数组。顺便说一句，在同一篇文章中问另一个问题从来都不是一个好主意，尤其是通过评论，因为不仅评论部分在提供正确答案方面有限制，而且也无法保证回答者知道下一部分的答案；）。