In [37]: df = pd.DataFrame([[1, 2, 3, 4], [2, 3, 4, 5], [3, 4, 5, 6]]) In [38]: df2 = pd.concat([df, df]) In [39]: df2.reset_index() Out[39]: index 0 1 2 3
You can use the drop=True option in reset_index(). See here.
drop=True
reset_index()