python - 用其他数据框中的值替换值

Question

我有两个数据框:

df1:

df2:

我想用 df1 值更新 df2 以创建:

生成以下示例数据框的代码:

import pandas as pd

test_dict = {'Customer': ['A', 'B', 'C'], 'Last Accessed': ['7/16/2020','7/5/2020', '7/1/2020']}
df1 = pd.DataFrame.from_dict(test_dict)

test_dict = {'Customer': ['A', 'B', 'C', 'D', 'E', 'F'], 'Date Accessed': ['5/15/2020','5/15/2020', '5/15/2020', '5/15/2020', '5/15/2020', '5/15/2020']}
df2 = pd.DataFrame.from_dict(test_dict)

Answer 1

让我们尝试 concat 然后 drop_duplicates

df = pd.concat([df1.rename(columns={'Last Accessed':'Date Accessed'}),df2]).drop_duplicates('Customer')
Out[81]: 
  Customer Date Accessed
0        A     7/16/2020
1        B      7/5/2020
2        C      7/1/2020
3        D     5/15/2020
4        E     5/15/2020
5        F     5/15/2020