data set index code example
Example 1: add an index column pandas
import numpy as np
import pandas as pd
df = pd.DataFrame({'month': [2, 5, 8, 10],
'year': [2017, 2019, 2018, 2019],
'sale': [60, 45, 90, 36]})
df.set_index('month')
Example 2: how to change index in dataframe python
index = [1,2]
df.index = index