使用 Pandas 将索引列添加到 DataFrame
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Add indexed column to DataFrame with pandas
提问by saroele
I'm a beginning pandas user, and after studying the documentation I still can't find a straightforward way to do the following.
我是 Pandas 的初级用户，在研究了文档后，我仍然找不到执行以下操作的简单方法。
I have a DataFrame with a pandas.DateRange index, and I want to add a column with values for part of the same DateRange.
我有一个带有 pandas.DateRange 索引的 DataFrame，我想添加一个列，其中包含同一 DateRange 的一部分的值。
Suppose I have
假设我有
df
A B
2010-01-01 00:00:00 0.340717 0.702432
2010-01-01 01:00:00 0.649970 0.411799
2010-01-01 02:00:00 0.932367 0.108047
2010-01-01 03:00:00 0.051942 0.526318
2010-01-01 04:00:00 0.518301 0.057809
2010-01-01 05:00:00 0.779988 0.756221
2010-01-01 06:00:00 0.597444 0.312495
and
和
df2
C
2010-01-01 03:00:00 5
2010-01-01 04:00:00 5
2010-01-01 05:00:00 5
How can I obtain something like this:
我怎样才能获得这样的东西：
A B C
2010-01-01 00:00:00 0.340717 0.702432 nan
2010-01-01 01:00:00 0.649970 0.411799 nan
2010-01-01 02:00:00 0.932367 0.108047 nan
2010-01-01 03:00:00 0.051942 0.526318 5
2010-01-01 04:00:00 0.518301 0.057809 5
2010-01-01 05:00:00 0.779988 0.756221 5
2010-01-01 06:00:00 0.597444 0.312495 nan
回答by Wes McKinney
回答by fantabolous
df['C'] = df2['C']should also work in this case.
df['C'] = df2['C']在这种情况下也应该工作。
