pandas: 合并行中的文本

Question

从下面这个数据表开始；

data1 = pd.DataFrame({'Section':[1,1,1,2,2,2,2],'Sub':['What','is','this?','I','am','not','sure.']})

我该怎么得到一个类似这样的结果；

['What is this?','I am not sure.']

到目前为止，我只想到用 groupby 这样的方法；

for d in data1.groupby(['Section'])['Sub']:
    print d[1]

这样做会得到类似这样的结果；

0     What
1       is
2    this?
Name: Sub, dtype: object
3        I
4       am
5      not
6    sure.
Name: Sub, dtype: object

Answer 1

用空格把这些项目连接起来：

In [34]: for d in data1.groupby(['Section'])['Sub']:
    ...:     print ' '.join(d[1])
What is this?
I am not sure.

然后把它们变成一个列表：

In [35]: [' '.join(d[1]) for d in data1.groupby(['Section'])['Sub']]
Out[35]: ['What is this?', 'I am not sure.']