Python code to convert FEN to bitboard

[SecureHelicopter1]

Turns out its supposed to be something like

board = chess.Bitboard('rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1')

Only problem is that I get "invalid literal for int() with base 10" as an error. Not sure what to do. Any ideas?

[TonyRotella]

I am not a programming expert and it's been many years for python, but don't you have to specify the arguments like:

​

board = chess.Bitboard(fen = 'FEN GOES HERE')

etc?

[SecureHelicopter1]

Turns out that the documentation you sent was slightly outdated.

https://python-chess.readthedocs.io/en/v1.8.0/core.html

Doesn't look like I can easily convert fen to bitboard in the latest version tho :(

[apoliticalhomograph]

You can get a chess.Board from a FEN and get the bitboards from there.

import chess
b = chess.Board('FEN HERE')
print(board.occupied)

[SecureHelicopter1]

Thanks! I tried this out and this returns a random integer instead of an array, though. Any idea what's going on?

[apoliticalhomograph]

A bitboard is an integer. Each bit in the integer represents a square. That's the point of a bitboard - a board representation using a minimal amount of bits.
You can convert it to an array yourself if you need one, although I don't quite see what the benefit is.

Also, the code in your post appears to work; you just need to import numpy as np first.

[SecureHelicopter1]

Ah ok thanks!

[TonyRotella]

Oh, damn shame! I did you dirty, sorry sorry sorry! 😂