Windowell Expressions -

Covers keep out leaves, snow, rain, and debris, reducing the need for maintenance.

def setUp(self): self.engine = WindowellEngine() self.df = pd.DataFrame( 'product': ['A', 'A', 'A', 'B', 'B'], 'date': pd.date_range('2024-01-01', periods=5), 'sales': [100, 150, 200, 50, 75] )