set index in pandas code example

Example 1: set index to column pandas

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

Example 2: pandas create a column from index

df.reset_index(level=0, inplace=True)

Example 3: how to set index pandas

# assignment copy
df = df.set_index('month')

# or inplace
df.set_index('month', inplace=True)

#      year   sale  month            month  year   sale
#  0   2012   55    1                1      2012   55
#  1   2014   40    4       =>       4      2014   40
#  2   2013   84    7                7      2013   84
#  3   2014   31    10               10     2014   31

Example 4: how to change indeces in pandas dataframe

>>> df.set_index('month')
       year  sale
month
1      2012    55
4      2014    40
7      2013    84
10     2014    31

Example 5: set index in datarame

df = df.set_index('col')

Example 6: how to change index in dataframe python

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