Pandas-如何将数据帧转置作为列标题附加到另一个数据帧？

Question

我需要在DF2中添加DF1值作为列

DataFrame1

DataFrame2（需要追加操作）

必需的DataFrame - DF3

Answer 1

尝试使用仅包含标头的空数据框select user_id, first_name, max(case when seqnum = 1 then order_date end) as order_date_1, max(case when seqnum = 2 then order_date end) as order_date_2, max(case when seqnum = 3 then order_date end) as order_date_3 from (select t.*, row_number() over (partition by user_id order by order_date) as seqnum from t where rnk_address = 1 ) t group by user_id, first_name; 。这是一个演示 -

pd.concat

Answer 2

使用DataFrame.join：

df2 = df1.join(pd.DataFrame(columns=df2['HeaderName']))

或assign：

df2 = df1.assign(**pd.Series(index=df2['HeaderName']))

Answer 3

我们可以使用IActionFilter

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