如何在python中使用pandas对多个DataFrames执行外部合并

import pandas as pd

df1 = pd.DataFrame({'A': [1, 2, 3], 'B': ['a', 'b', 'c']})
df2 = pd.DataFrame({'A': [4, 5, 6], 'B': ['d', 'e', 'f']})

merged_df = pd.merge(df1, df2, on='A', how='outer')

print(merged_df)

import pandas as pd

df1 = pd.DataFrame({'A': [1, 2, 3], 'B': ['a', 'b', 'c']})
df2 = pd.DataFrame({'A': [4, 5, 6], 'B': ['d', 'e', 'f']})

merged_df = pd.merge(df1, df2, on='A', how='outer')
print(merged_df)

   A  B_x  B_y
0  1    a  NaN
1  2    b  NaN
2  3    c  NaN
3  4  NaN    d
4  5  NaN    e
5  6  NaN    f