Python for SAS Users: A SAS-Oriented Introduction to Python

© Randy Betancourt, Sarah Chen 2019

R. Betancourt, S. ChenPython for SAS Usershttps://doi.org/10.1007/978-1-4842-5001-3_4

4. Indexing and GroupBy

Randy Betancourt¹  and Sarah Chen²

(1)

Chadds Ford, PA, USA

(2)

Livingston, NJ, USA

 

SAS users tend to think of indexing SAS datasets to either improve query performance or as a method to avoid dataset sorting. Another use case for using SAS indexes is to provide direct access to a specific observation in a dataset. For example, in order to retrieve an observation whose value for the variable name is ‘Lassiter’, absent an index, SAS performs a sequential read starting with the first observation in the dataset. SAS normally begins reading at observation 1 reading the dataset in sequence for name = ‘Lassiter’ ...