pandas.Series.rank

Series.rank(method='average', na_option='keep', ascending=True)

Compute data ranks (1 through n). Equal values are assigned a rank that is the average of the ranks of those values

method : {‘average’, ‘min’, ‘max’, ‘first’}
average: average rank of group min: lowest rank in group max: highest rank in group first: ranks assigned in order they appear in the array
na_option : {‘keep’}
keep: leave NA values where they are
ascending : boolean, default True
False for ranks by high (1) to low (N)

ranks : Series