如何從表中獲取包含 sql 或 python 的字符串列表列的表

Question

我有如下表

eventID countries
aaffff. Japan, US, Frunce
aafggg. Japan, Frunce

我想買新桌子

eventID countries
aaffff. Japan
aaffff. US
aaffff. Frunce
aafggg. Japan
aafggg. Frunce

因為我不知道我將在列國家/地區擁有多少字符串，所以 function Split_part 不會幫助我。 如果 python 有更好的方法，我會很高興聽到。

Answer 1

In [24]: a = [{"eventID":"aaffff","countries":"Japan, US, Frunce"},{"eventID":"aafggg","countries":"Japan, Frunce"}]

In [25]: df = pd.DataFrame(a)

In [26]: df
Out[26]:
  eventID          countries
0  aaffff  Japan, US, Frunce
1  aafggg      Japan, Frunce

In [28]: df["countries"] = df["countries"].str.split(",")

In [29]: df
Out[29]:
  eventID              countries
0  aaffff  [Japan,  US,  Frunce]
1  aafggg       [Japan,  Frunce]

In [30]: df.explode("countries")
Out[30]:
  eventID countries
0  aaffff     Japan
0  aaffff        US
0  aaffff    Frunce
1  aafggg     Japan
1  aafggg    Frunce