chessengine.lookup_tables

The lookup tables module provides mappings between different position representation formats, as well as utility bitboards that let you mask or clear individual ranks, files, or positions on the chess board.

chessengine.lookup_tables.pos_to_coords

Type:

dict[int, str]

A dictionary mapping position indices on the board to their square names. 0 is mapped to “A1”, 1 is mapped to “B1”, 8 is mapped to “A2”, 9 is mapped to “B2”, and so on.

chessengine.lookup_tables.coords_to_pos

Type:

dict[str, int]

A dictionary mapping squares on the board to their position indices. Basically the reverse mapping of pos_to_coords. “A1” is mapped to 0, “B1” is mapped to 1, “A2” is mapped to 8, “B2” is mapped to 9, and so on.

chessengine.lookup_tables.clear_rank

Type:

dict[int, int]

A dictionary mapping ranks to a bitboard having 0s only on that rank. For example, clear_rank[1] is a bitboard having only 0s on positions on the first rank, and 1s on all other positions.

chessengine.lookup_tables.mask_rank

Type:

dict[int, int]

A dictionary mapping ranks to a bitboard having 1s only on that rank, and 0s on all other ranks. For example, mask_rank[1] is a bitboard having only 1s on positions on the first rank, and 0s on all other position.

chessengine.lookup_tables.clear_file

Type:

dict[int, int]

A dictionary mapping files to a bitboard having 0s only on that file, and 1s on all other ranks. For example, clear_file[1] is a bitboard having only 0s on positions on the first file, and 1s on all other positions.

chessengine.lookup_tables.mask_file

Type:

dict[int, int]

A dictionary mapping files to a bitboard having 1s only on that file, and 0s on all other ranks. For example, mask_file[1] is a bitboard having only 1s on positions on the first file, and 0s on all other positions.

chessengine.lookup_tables.clear_position

Type:

dict[int, int]

A dictionary mapping positions to bitboards with a 0 at that position and 1 at all other positions.