# Define df
df = pd.DataFrame({"A": [1, 2, 3], "B": [4, 5, 6]})
# Option 1
df = df.rename({"A": "a", "B": "c"}, axis=1)
# or
df.rename({"A": "a", "B": "c"}, axis=1, inplace=True)
# Option 2
df = df.rename(columns={"A": "a", "B": "c"})
# or
df.rename(columns={"A": "a", "B": "c"}, inplace=True)
# Result
>>> df
a c
0 1 4
1 2 5
2 3 6