Declare chess.popcount in pyright compatible way

niklasf · Oct 8, 2023 · 3a99f1b · 3a99f1b
1 parent 1dd3e1e
commit 3a99f1b
Showing 1 changed file with 6 additions and 2 deletions.
diff --git a/chess/__init__.py b/chess/__init__.py
@@ -297,8 +297,12 @@ def scan_reversed(bb: Bitboard) -> Iterator[Square]:
         yield r
         bb ^= BB_SQUARES[r]
 
-# Python 3.10 or fallback.
-popcount: Callable[[Bitboard], int] = getattr(int, "bit_count", lambda bb: bin(bb).count("1"))
+try:
+    # Python 3.10
+    popcount = Bitboard.bit_count
+except AttributeError:
+    def popcount(self: Bitboard) -> int:
+        return bin(self).count("1")
 
 def flip_vertical(bb: Bitboard) -> Bitboard:
     # https://www.chessprogramming.org/Flipping_Mirroring_and_Rotating#FlipVertically