valid data points in an array it is similar to the indirect sort indices produced by numpy argsortexcept that ties are broken according to rule the rank methods for series and dataframe are the place to lookby default rank breaks ties by assigning each group the mean rankin [ ]obj series([ - ]in [ ]obj rank(out[ ] ranks can also be assigned according to the order they're observed in the datain [ ]obj rank(method='first'out[ ] naturallyyou can rank in descending ordertooin [ ]obj rank(ascending=falsemethod='max'out[ ] see table - for list of tie-breaking methods available dataframe can compute ranks over the rows or the columnsin [ ]frame dataframe({' '[ - ]' '[ ]' '[- - ]}in [ ]frame out[ ] - - - in [ ]frame rank(axis= out[ ] essential functionality www it-ebooks info