Pandas recalculate index after a concatenation

Question

I have a problem where I produce a pandas dataframe by concatenating along the row axis (stacking vertically).

Each of the constituent dataframes has an autogenerat

Answer 1

After vertical concatenation, if you get an index of [0, n) followed by [0, m), all you need to do is call reset_index:

train_df.reset_index(drop=True)

(you can do this in place using inplace=True).

---

import pandas as pd

>>> pd.concat([
    pd.DataFrame({'a': [1, 2]}), 
    pd.DataFrame({'a': [1, 2]})]).reset_index(drop=True)
    a
0   1
1   2
2   1
3   2