重塑熊猫数据框失败

Question

我想重塑我的数据框，它只有键值对。

例如，

             key                                              value

0     Message-ID       <5525962.1075855679785.JavaMail.evans@thyme>

1           Date              Wed, 13 Dec 2000 07:04:00 -0800 (PST)

2           From                            [e-mail]

3             To  [e-mail], james.steffes@enron...

4         X-From                                    Phillip K Allen

5           X-To  Christi L Nicolay, James D Steffes, Jeff Dasov...

6          X-cc:                                               None

7         X-bcc:                                               None

8       X-Origin                                            Allen-P

9     Message-ID       <4650921.1075855679981.JavaMail.evans@thyme>

10          Date               Tue, 5 Dec 2000 07:31:00 -0800 (PST)

11          From                               [e-mail]

12            To                             [e-mail]

13        X-From                                         Ina Rangel

14          X-To                                       Amanda Huble

15         X-cc:                                               None

16        X-bcc:                                               None

17      X-Origin                                            Allen-P

我想把它变成：

Message-ID       Date                  From             To        X-From                 X-To                            X-cc:  X-bcc:  X-Origin

<5525962.10...   Wed, 13 Dec 2000...   phillip.allen... christi.nicolay.. Phillip K Allen..     Christi L Nicolay, Ja... NaN    NaN     Allen-P

<4650921.10...   Tue, 5 Dec 2000 ...   ina.rangel...    amanda.huble@...  Ina Rangel            Amanda Huble             NaN    NaN     Allen-P

我尝试旋转表格，但我很困惑我应该提供什么作为索引参数。请帮我解决这个问题。

如果您发现它，请随意标记为重复。

Answer 1

如果每个组具有总是9值是可能的用途numpy.reshape为2d array与DataFrame构造器，也可用于列的值先取列值9 key：print (df['value'].values.reshape(-1, 9))[['<5525962.1075855679785.JavaMail.evans@thyme>'&nbsp; 'Wed, 13 Dec 2000 07:04:00 -0800 (PST)' '[e-mail]'&nbsp; '[e-mail], james.steffes@enron...' 'Phillip K Allen'&nbsp; 'Christi L Nicolay, James D Steffes, Jeff Dasov...' 'None' 'None'&nbsp; 'Allen-P']&nbsp;['<4650921.1075855679981.JavaMail.evans@thyme>'&nbsp; 'Tue, 5 Dec 2000 07:31:00 -0800 (PST)' '[e-mail]'&nbsp; '[e-mail]' 'Ina Rangel' 'Amanda Huble' 'None' 'None'&nbsp; 'Allen-P']]df = pd.DataFrame(df['value'].values.reshape(-1, 9), columns=df['key'].iloc[:9])print (df)key&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Message-ID&nbsp; \0&nbsp; &nbsp; <5525962.1075855679785.JavaMail.evans@thyme>&nbsp; &nbsp;1&nbsp; &nbsp; <4650921.1075855679981.JavaMail.evans@thyme>&nbsp; &nbsp;key&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Date&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;From&nbsp; \0&nbsp; &nbsp; Wed, 13 Dec 2000 07:04:00 -0800 (PST)&nbsp; [e-mail]&nbsp; &nbsp;1&nbsp; &nbsp; &nbsp;Tue, 5 Dec 2000 07:31:00 -0800 (PST)&nbsp; &nbsp; &nbsp;[e-mail]&nbsp; &nbsp;key&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;To&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;X-From&nbsp; \0&nbsp; &nbsp; [e-mail], james.steffes@enron...&nbsp; Phillip K Allen&nbsp; &nbsp;1&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;[e-mail]&nbsp; &nbsp; &nbsp; &nbsp;Ina Rangel&nbsp; &nbsp;key&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;X-To X-cc: X-bcc: X-Origin&nbsp;&nbsp;0&nbsp; &nbsp; Christi L Nicolay, James D Steffes, Jeff Dasov...&nbsp; None&nbsp; &nbsp;None&nbsp; Allen-P&nbsp;&nbsp;1&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Amanda Huble&nbsp; None&nbsp; &nbsp;None&nbsp; Allen-P&nbsp;如果Message-ID每个组的数据总是可以set_index与布尔掩码Series创建的助手一起使用cumsum- 比较用于识别每个组的开始：eq ==df = df.set_index([df['key'].eq('Message-ID').cumsum(), 'key'])['value'].unstack()print (df)key&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Date&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;From&nbsp; \key&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;1&nbsp; &nbsp; Wed, 13 Dec 2000 07:04:00 -0800 (PST)&nbsp; [e-mail]&nbsp; &nbsp;2&nbsp; &nbsp; &nbsp;Tue, 5 Dec 2000 07:31:00 -0800 (PST)&nbsp; &nbsp; &nbsp;[e-mail]&nbsp; &nbsp;key&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Message-ID&nbsp; \key&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;1&nbsp; &nbsp; <5525962.1075855679785.JavaMail.evans@thyme>&nbsp; &nbsp;2&nbsp; &nbsp; <4650921.1075855679981.JavaMail.evans@thyme>&nbsp; &nbsp;key&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;To&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;X-From&nbsp; \key&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;1&nbsp; &nbsp; [e-mail], james.steffes@enron...&nbsp; Phillip K Allen&nbsp; &nbsp;2&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;[e-mail]&nbsp; &nbsp; &nbsp; &nbsp;Ina Rangel&nbsp; &nbsp;key X-Origin&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;X-To X-bcc: X-cc:&nbsp;&nbsp;key&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;1&nbsp; &nbsp; Allen-P&nbsp; Christi L Nicolay, James D Steffes, Jeff Dasov...&nbsp; &nbsp;None&nbsp; None&nbsp;&nbsp;2&nbsp; &nbsp; Allen-P&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Amanda Huble&nbsp; &nbsp;None&nbsp; None&nbsp;&nbsp;