Windowell Expressions — ((top))

def __init__(self): self.window_registry: dict[str, WindowellExpression] = {}

def test_dynamic_boundary(self): self.df['threshold'] = [1, 2, 1, 3, 2] dynamic = DynamicBoundary(lambda df: df['threshold'].median()) self.assertEqual(dynamic.evaluate(self.df), 2) if == ' main ': unittest.main() 5. Performance Optimizations class OptimizedWindowellEngine(WindowellEngine): """Performance-optimized version""" def apply_window_optimized(self, df, window, agg_func, alias): """Use vectorized operations where possible""" window_expr = self.resolve_window(window) if not window_expr.order_by and not window_expr.frame: # Simple partition aggregate (fast path) return df.assign(** alias: df.groupby(window_expr.partition_by)[agg_func.__name__].transform(agg_func) ) # Use numba for JIT-compiled rolling windows if window_expr.frame and window_expr.frame.frame_type == 'rows': return self._numba_rolling_apply(df, window_expr, agg_func, alias) return super().apply_window(df, window, agg_func, alias) windowell expressions

def resolve_window(self, window_spec: str | WindowellExpression) -> WindowellExpression: """Resolve window reference with optional overrides""" if isinstance(window_spec, str): base = self.window_registry.get(window_spec) if not base: raise ValueError(f"Undefined window: window_spec") return base return window_spec def __init__(self): self

@staticmethod def overlay(window1: WindowellExpression, window2: WindowellExpression): """Overlay windows: combine frame definitions""" return WindowellExpression( partition_by=window1.partition_by or window2.partition_by, order_by=window1.order_by or window2.order_by, frame=window2.frame if window2.frame else window1.frame ) class DynamicBoundary: """Compute frame boundaries dynamically from data""" def __init__(self, expression: Callable[[pd.DataFrame], int]): self.expression = expression def __init__(self): self.window_registry: dict[str

def test_named_window(self): weekly = WindowellBuilder()\ .partition('product')\ .order('date')\ .rows_between(3, 'preceding', 0, 'current_row')\ .build('weekly_sales') self.engine.define_window('weekly_sales', weekly) result = self.engine.apply_window( self.df, 'weekly_sales', lambda x: x['sales'].mean(), 'moving_avg' ) self.assertIn('moving_avg', result.columns) self.assertEqual(len(result), 5)

def define_window(self, name: str, expression: WindowellExpression): """Register a named window template""" self.window_registry[name] = expression return self

def range_between(self, start: int, end: int): self.frame = WindowFrame( start=(start, FrameBound.PRECEDING), end=(end, FrameBound.FOLLOWING), frame_type="range" ) return self