我相信 DataFrame.merge 在这种情况下会起作用：

I believe that DataFrame.merge would work in this case:

# use how='outer' to preserve all information from both DataFrames
df1.merge(df2, how='outer', on='customer_id')

DataFrame.join 也可以工作这两个DataFrame的索引都设置为 customer_id （也更简单）：

DataFrame.join could also work if both DataFrames had their indexes set to customer_id (it is also simpler):

df1 = df1.set_index('customer_id')
df2 = df2.set_index('customer_id')
df1.join(df2, how='outer')

• DataFrame.merge
$的文档b $ b
• DataFrame.join


• Documentation for DataFrame.merge
• Documentation for DataFrame.join