python - 如何从数据框列值创建多个列表

Question

df1

    Ticker          Category
0      XOM           Group 1
1      CVX           Group 1
2  RDSA-GB           Group 2
3    BP-GB  Group 1, Group 2
4  EQNR-NO           Group 3
5    FP-FR           Group 4
6   ENI-IT  Group 3, Group 4
7      COP           Group 5

我想要的结果将基于“类别”列和名称创建“股票代码”列表，列出“类别”值，同时用“_”替换空格

其次，如果存在类别有两个值的实例，例如“US Major、Euro Major”，那么我如何确保“Ticker”最终出现在两个类别列表中？

Group_1 = ['XOM','CVX','BP-GB']
Group_2 = ['RDSA-GB','BP-GB']
Group_3 = ['EQNR-NO','ENI-IT']
Group_4 = ['FP-FR','ENI-IT']
Group_5 = ['COP']

谢谢!

Answer 1

好吧，你说列出列表，我想你的意思是用字典的方式？如果是这种情况，请尝试以下操作:

import pandas as pd

df =  pd.DataFrame([["XOM","US Major"],
["CVX","US Major"],
["RDSA-GB","Euro Major"],
["BP-GB","Euro Major"],
["EQNR-NO","Euro Major"]],columns=["Ticker","Category"])

df_to_lists = df.groupby("Category")["Ticker"].apply(list)
lists_to_dict = dict(df_to_lists)
print(lists_to_dict)

输出:

{'Euro Major': ['RDSA-GB', 'BP-GB', 'EQNR-NO'], 'US Major': ['XOM', 'CVX']}

如果您不需要字典，则 df_to_lists 输出:

Category
Euro Major    [RDSA-GB, BP-GB, EQNR-NO]
US Major                     [XOM, CVX]
Name: Ticker, dtype: object