updated from Atlas

11-pythonic-obj/patterns.py

@@ -0,0 +1,53 @@
+from vector2d_v3 import Vector2d
+
+# tag::KEYWORD_PATTERNS[]
+def keyword_pattern_demo(v: Vector2d) -> None:
+    match v:
+        case Vector2d(x=0, y=0):
+            print(f'{v!r} is null')
+        case Vector2d(x=0):
+            print(f'{v!r} is vertical')
+        case Vector2d(y=0):
+            print(f'{v!r} is horizontal')
+        case Vector2d(x=x, y=y) if x==y:
+            print(f'{v!r} is diagonal')
+        case _:
+            print(f'{v!r} is awesome')
+# end::KEYWORD_PATTERNS[]
+
+# tag::POSITIONAL_PATTERNS[]
+def positional_pattern_demo(v: Vector2d) -> None:
+    match v:
+        case Vector2d(0, 0):
+            print(f'{v!r} is null')
+        case Vector2d(0):
+            print(f'{v!r} is vertical')
+        case Vector2d(_, 0):
+            print(f'{v!r} is horizontal')
+        case Vector2d(x, y) if x==y:
+            print(f'{v!r} is diagonal')
+        case _:
+            print(f'{v!r} is awesome')
+# end::POSITIONAL_PATTERNS[]
+
+
+def main():
+    vectors = (
+        Vector2d(1, 1),
+        Vector2d(0, 1),
+        Vector2d(1, 0),
+        Vector2d(1, 2),
+        Vector2d(0, 0),
+    )
+    print('KEYWORD PATTERNS:')
+    for vector in vectors:
+        keyword_pattern_demo(vector)
+
+    print('POSITIONAL PATTERNS:')
+    for vector in vectors:
+        positional_pattern_demo(vector)
+
+
+
+if __name__ == '__main__':
+    main()