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

Parameters :

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)

Returns :

ranks : Series