在Pandas中将单元格分解为多行

Question

如何在Pandas中将单元格中的内容分解为多行？

ID  CODES
A   {"1407273790":5,"1801032636":20,"1174813554":1,"1215470448":2,"1053754655":4,"1891751228":1}
B   {"1497066526":19,"1639360563":16,"1235107087":11,"1033522925":18}
C   {"1154348191":8,"1568410355":4}

如何将“”中的代码分解为多行？我正在查看的输出如下表所示

ID  CODES
A   1407273790
A   1801032636
A   1174813554
A   1215470448
A   1053754655
A   1891751228
B   1497066526
B   1639360563
B   1235107087
B   1033522925
C   1154348191
C   1568410355

Answer 1

获取keys()后即可使用explode。keys()返回一个tuple，所以我使用[*]将其转换为一个列表，这是explode所需的格式。您也可以使用list()

df = pd.DataFrame({'ID' : ['A', 'B', 'C'],
'CODES' : [{"1407273790":5,"1801032636":20,"1174813554":1,"1215470448":2,"1053754655":4,"1891751228":1},
{"1497066526":19,"1639360563":16,"1235107087":11,"1033522925":18},
{"1154348191":8,"1568410355":4},]})
df['CODES'] = df['CODES'].apply(lambda x: [*x.keys()]) # or lambda x: list(x.keys()))
df = df.explode('CODES')
df
Out[1]: 
  ID       CODES
0  A  1407273790
0  A  1801032636
0  A  1174813554
0  A  1215470448
0  A  1053754655
0  A  1891751228
1  B  1497066526
1  B  1639360563
1  B  1235107087
1  B  1033522925
2  C  1154348191
2  C  1568410355

根据SammyWemmy的评论，您可以使用以下命令尝试两种方法的性能：

%timeit df['CODES'].apply(lambda x: list(x.keys()))
%timeit [entry.keys() for entry in df.CODES]