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

1"""Count feature""" 

2 

3from typing import Callable 

4import pyspark.sql.functions as f 

5from pyspark.sql import Column 

6 

7 

8from jstark.features.feature import BaseFeature 

9 

10 

11class Count(BaseFeature): 

12 def aggregator(self) -> Callable[[Column], Column]: 

13 return self.count_aggregator 

14 

15 def column_expression(self) -> Column: 

16 return f.lit(1) 

17 

18 def default_value(self) -> Column: 

19 return f.lit(0) 

20 

21 @property 

22 def description_subject(self) -> str: 

23 return "Count of rows"