Coverage for jstark/features/average_quantity_per_basket.py: 100%

1"""AverageQuantityPerBasket feature""" 

2import pyspark.sql.functions as f 

3from pyspark.sql import Column 

4 

5from .feature import DerivedFeature 

6from .quantity import Quantity 

7from .basket_count import BasketCount 

8 

9 

10class AvgQuantityPerBasket(DerivedFeature): 

11 def column_expression(self) -> Column: 

12 return ( 

13 Quantity(self.as_at, self.feature_period).column 

14 / BasketCount(self.as_at, self.feature_period).column 

15 ) 

16 

17 @property 

18 def description_subject(self) -> str: 

19 return "Average Quantity per Basket" 

20 

21 @property 

22 def commentary(self) -> str: 

23 return ( 

24 "Total Quantity divided by the number of baskets. " 

25 + "Very useful to know how large, on average, each basket is." 

26 ) 

27 

28 def default_value(self) -> Column: 

29 return f.lit(None)