How to Find the King’s Legal Moves in Chess With Python

A fun exercise to sharpen your brain and your code

Photo by Pixabay from Pexels

Have you ever wondered how you can find the king’s legal moves on a chessboard with Python? Probably not, but it’s a fun exercise in jumping around in a grid made by lists.

The king can only move one square in any direction. This means it can do eight legal moves unless it is on the edge or in a corner.

I have added a challenge for you at the end as well. Are you going to take it?

In this program we’ll:

• Create a menu for the user so he/she can place a king on a board
• Print the board seen from black or white’s perspective
• Print the king’s legal moves based on where the user places his/her king

The Board

Board from chess.com

To write this program, we’ll use one class called Board in board.py and a main.py to run it.

The creation of the board is quite easy but still has a very nice touch to it. I’ll use list comprehension to fill a list with eight lists (rows). These will have eight items inside (columns).

A chessboard is 8x8 squares. The rows are numbered, and columns are identified by a letter A-H.

Here’s the Class Board

def __init__(self)

• The first thing you notice is the self._letters list. This is simply the range of letters possible on a chessboard as strings — e.g., A-H.
• The next list is self._board_grid. This list is empty for now and will be populated with several lists, representing rows.
• The loop for letters in self._letters: uses list comprehension to do the following: