pandas 合并数据帧不同的行数重复数据

Question

我有两个要合并的数据框（df1 和 df2）。我想要 df1 中每一行的价格和代码。我怎样才能合并这些，以便价格和代码自行重复并根据水果排列？我认为我需要将水果设置为索引才能执行此操作？

df1 =

fruit grown    farm
    apple   fruit ranch
    banana  fresh grow
    grapes  paradise lake
    melon   country hills
    cherry  paradise lake
    orange  paradise lake
    apple   fruit ranch
    apple   paradise lake
    cherry  fresh grow
    grapes  fruit ranch
    apple   country hills
    melon   paradise lake
    cherry  fruit ranch
    orange  fresh grow

df2 =

fruit   price   code
apple    3      568
banana   2      426
grapes   4      112
melon    6      368
cherry   1      569
orange   4      775

谢谢

Answer 1

您只需使用 pandas.DataFrame.merge 合并它们，但您可能希望先更改列名，然后才能合并它们。

df1.merge(df2.rename(columns={'fruit':'fruit grown'}), how='left')

输出:

   fruit grown           farm  price  code
0        apple    fruit ranch      3   568
1       banana     fresh grow      2   426
2       grapes  paradise lake      4   112
3        melon  country hills      6   368
4       cherry  paradise lake      1   569
5       orange  paradise lake      4   775
6        apple    fruit ranch      3   568
7        apple  paradise lake      3   568
8       cherry     fresh grow      1   569
9       grapes    fruit ranch      4   112
10       apple  country hills      3   568
11       melon  paradise lake      6   368
12      cherry    fruit ranch      1   569
13      orange     fresh grow      4   775

pandas 合并数据帧不同的行数重复数据

pandas merge dataframes different line count repeat data

python

pandas

merge

repeat