在Python中组合多个值

Question

我有以下格式的数据（在csv文件中）：

 id, review
 1, the service was great!
 1, staff was friendly.
 2, nice location
 2, but the place was not clean
 2, the motel was okay
 3, i wouldn't stay there next time
 3, do not stay there

我想将数据更改为以下格式：

 1, the service was great! staff was friendly. 
 2, nice location but the place was not clean the motel was okay
 3, i wouldn't stay there next time do not stay there

任何帮助将不胜感激。

Answer 1

您可以使用itertools.groupby对具有相同编号的连续条目进行分组。

import itertools, operator, csv
with open("test.csv") as f:
    reader = csv.reader(f, delimiter=",")
    next(reader) # skip header line
    for key, group in itertools.groupby(reader, key=operator.itemgetter(0)):
        print key, ' '.join(g[1] for g in group)

输出：

1  the service was great!  staff was friendly.
2  nice location  but the place was not clean  the motel was okay
3  i wouldn't stay there next time  do not stay there

注意：读取文件的代码假设它是一个实际的CSV文件，带有,分隔符：

id, review
1, the service was great!
...