Made requested changes

Author: AInnuganti

chess/__init__.py

@@ -220,25 +220,18 @@ def square_distance(a: Square, b: Square) -> int:
     """
     Gets the Chebyshev distance (i.e., the number of king steps) from square *a* to *b*.
     """
-    if a == b:
-        return 0;
     return max(abs(square_file(a) - square_file(b)), abs(square_rank(a) - square_rank(b)))
 
 def square_manhattan_distance(a: Square, b: Square) -> int:
     """
     Gets the Manhattan/Taxicab distance (i.e., the number of orthogonal king steps) from square *a* to *b*.
     """
-    if a == b:
-        return 0;
     return abs(square_file(a) - square_file(b)) + abs(square_rank(a) - square_rank(b))
 
 def square_knight_distance(a: Square, b: Square) -> int:
     """
     Gets the Knight distance (i.e., the number of knight moves) from square *a* to *b*.
     """
-    if a == b:
-        return 0;
-
     dx = abs(square_file(a) - square_file(b))
     dy = abs(square_rank(a) - square_rank(b))
 
@@ -247,7 +240,7 @@ def square_knight_distance(a: Square, b: Square) -> int:
     elif dx == dy == 2:
         return 4
     elif dx == dy == 1:
-        if 1 << a & BB_CORNERS or 1 << b & BB_CORNERS: # Special case only for corner squares
+        if BB_SQUARES[a] & BB_CORNERS or BB_SQUARES[b] & BB_CORNERS: # Special case only for corner squares
             return 4
 
     m = math.ceil(max(dx / 2, dy / 2, (dx + dy) / 3))