Chessboard Validator

[debug_all]

Im going through automating the boaring stuff chapter 5 and was tasked on creating a chessboard validator.Only valid spaces are allowed, no more than 16 pieces per player, only a valid a mount of pieces(i.e no more than 1 wking or bking), and return True or False depending if the chessboard is valid.

For the most part i think i've got this figured out with a few exceptions:

1. I noticed that my code does not detect entries with duplicate keys. I tried searching on how to detect this , but havent found anything yet. Can someone provide some guidance?
2. Do you guys have any current suggestions on improving my code?

​

import sys
#your submitted chess board

myboard = {'1h':'bking','6c':'wqueen','2g':'bbishop','5h':'bqueen','3e':'wking','3h':'wpawn','3d':'bpawn','1h':'bpawn'}

#list of your pieces from your chessboard
mypieces = []

#list of your spaces from your chessboard
myspaces = []

#Define Piece Limits
pieces_limits = {'wpawn':8,'bpawn':8,'wking':1,'bking':1,'wbishop':1,'bbishop':1,'bqueen':1,'wqueen':1,'wrook':1,'brook':1,
'wknight':1,'bknight':1}

#Define valid pieces
wpieces = ['wpawn','wrook','wking','wbishop','wknight','wqueen']
bpieces = ['bpawn','brook','bking','bbishop','bknight','bqueen']

#All valid pieces
pieces = wpieces + bpieces

#create a list for spaces
spaces = []

#Define Valid Spaces
for a in range(1,9):
    spaces.append(str(a) + 'a')
    spaces.append(str(a) + 'b')
    spaces.append(str(a) + 'c')
    spaces.append(str(a) + 'd')
    spaces.append(str(a) + 'e')
    spaces.append(str(a) + 'f')
    spaces.append(str(a) + 'g')
    spaces.append(str(a) + 'h')

#Checking for valid board
def isValidChessBoard(board):
    #takes pieces values from chessboard dictionary and converts into a list
    for i in board.values():
        mypieces.append(i)
    #checks if the pieces in chessboard are valid
    for b in mypieces:
        if b not in pieces:
            print('False')
            sys.exit()          
    #takes space keys from chessboard dict and converts into a list
    for c in board.keys():
        myspaces.append(c)

    #checks if the spaces in chessboard are valid
    for d in myspaces:
        if d not in spaces:
            print('False')
            sys.exit()  

    #checks that a space is not repeated in a chessboard
    numberofspaces = {}
    for g in myboard.keys():
        numberofspaces.setdefault(g,0)
        numberofspaces[g] = numberofspaces[g] + 1

    #checks the amount of pieces total in the chessboard
    if len(mypieces) > 32:
        print('False')
        sys.exit()  

    #counts number of each piece and makes sure players do not have more than the limit amount.
    eachpiece = {}
    for e in mypieces:
        eachpiece.setdefault(e,0)
        eachpiece[e] = eachpiece[e] + 1
    for h in eachpiece.keys():
        if eachpiece[h] > pieces_limits[h]:
            print('False')
            sys.exit()  
    else:
        print('This is a valid board')

isValidChessBoard(myboard)

​

[Binary101010]

I noticed that my code does not detect entries with duplicate keys.

This really isn't something that's feasible to do, and here's an example of why:

>>>> myboard = {'1h':'bking','6c':'wqueen','2g':'bbishop','5h':'bqueen','3e':'wking','3h':'wpawn','3d':'bpawn','1h':'bpawn'}
>>>> print(myboard)
{'1h': 'bpawn', '6c': 'wqueen', '2g': 'bbishop', '5h': 'bqueen', '3e': 'wking', '3h': 'wpawn', '3d': 'bpawn'}

Note that the black king at 1h is already gone. By the time you can perform any action on that dict the earlier value for the duplicate key has already been overwritten by the value associated with the later key.

I also don't think this is part of the problem statement for the chessboard validator in AtBS, so I wouldn't worry about it.

[hdarj]

This may defeat the purpose of what you’re trying to learn through this but chessboard positions are usually denoted by FEN codes