python-2.7 - 如何在 Pandas 中删除两个数据框中的公共(public)行？

Question

我有两个数据框 - df1和 df2 .

df1 has row1,row2,row3,row4,row5
df2 has row2,row5

我想要一个新的数据框，这样 df1-df2 .也就是说，结果数据帧的行应为 - row1,row3,row4 .

Answer 1

您可以使用 pandas.concat 按行连接两个数据帧，然后是 drop_duplicates 删除其中所有重复的行。

In [1]: import pandas as pd
df_1 = pd.DataFrame({"A":["foo", "foo", "foo", "bar"], "B":[0,1,1,1], "C":["A","A","B","A"]})
df_2 = pd.DataFrame({"A":["foo", "bar", "foo", "bar"], "B":[1,0,1,0], "C":["A","B","A","B"]})

In [2]: df = pd.concat([df_1, df_2])

In [3]: df
Out[3]: 
     A  B  C
0  foo  0  A
1  foo  1  A
2  foo  1  B
3  bar  1  A
0  foo  1  A
1  bar  0  B
2  foo  1  A
3  bar  0  B

In [4]: df.drop_duplicates(keep=False)
Out[4]: 
     A  B  C
0  foo  0  A
2  foo  1  B
3  bar  1  A