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