pandas set index

1df = df.set_index('col')
2df['col'] = df.index

1# assignment copy
2df = df.set_index('month')
3
4# or inplace
5df.set_index('month', inplace=True)
6
7#      year   sale  month            month  year   sale
8#  0   2012   55    1                1      2012   55
9#  1   2014   40    4       =>       4      2014   40
10#  2   2013   84    7                7      2013   84
11#  3   2014   31    10               10     2014   31

1>>> df.set_index('month')
2       year  sale
3month
41      2012    55
54      2014    40
67      2013    84
710     2014    31
8

1import numpy as np
2import pandas as pd
3df = pd.DataFrame({'month': [2, 5, 8, 10],
4                   'year': [2017, 2019, 2018, 2019],
5                   'sale': [60, 45, 90, 36]})
6df.set_index('month')

1index = [1,2]
2df.index = index

1>>> college_idx = college.set_index('instnm')>>> sats = college_idx[['satmtmid', 'satvrmid']].dropna()>>> sats.head()