snake.py

import random
from time import sleep
import math
import pynput
from threading import *
from pynput.keyboard import Listener
from termcolor import colored
from os import system

# all of the variables here are needed to break out of while loops using pynput
downkey = False
leftkey = False
rightkey = False
upkey = False
dead = False

framerate = 0.075
score = 0
boardlen = 25
boardwidth = 50

class Board:
    
    def __init__(self, rows, columns,framerate):
        self.framerate = framerate
        self.board = [[' ' for column in range(columns)] for row in range(rows)]
        self.rows = rows
        self.columns = columns   
        
    def draw_board(self,score):
        system('clear')
        print(f'score : {score}')
        print('   ----'+'-' * (len(range(self.columns)) - 1),)
        for i in range(self.rows):    
            print('   | '+''.join(self.board[i])+ '|',)
        print('   ', end= '')
        print( ' \u203E\u203E'+ '\u203E' * (len(range(self.columns))))
        sleep(self.framerate)

    def placefood(self):
        self.food = colored('*', 'red')
        while True:    
            y = random.randint(0,self.rows-1)
            x = random.randint(0, self.columns-1)
            if self.board[y][x] == ' ':
                self.board[y][x] = self.food
                return            

# info to clean up the snake class

class Head:
    def __init__(self,starty,startx):
        self.head = colored('0', 'magenta')
        self.y = starty
        self.x = startx

class Snake():
    def __init__(self, board, head):
        self.length = 1
        # y and x directions need to be etsablished in init so i can manipulate
        # them later with other functions.
        self.ydir = 0
        self.xdir = 0
        self.head =  head
        self.board = board
        self.moves = []
        self.snakebody = colored('#', 'green')


    def check_and_replace_food(self):
        if self.board.board[self.head.y][self.head.x] == self.board.food:
            self.length += 1
            self.board.placefood() 
   
    def checkdeath(self):
        global dead # global needed for pynput to stop taking input.
        dead = False 
        try:
            if self.board.board[self.head.y][self.head.x] == self.snakebody:
                dead = True
            if self.head.y < 0 or self.head.x < 0:
                dead = True
        except:
            dead = True
        
        if dead:
            print('\n' * 5 + 'YOU DIED :(' + '\n' * 4)
            listener.stop()
            exit()
   
    def trim_and_place_body(self):
        if len(self.moves) >= 1:  
            self.board.board[self.moves[-self.length][0]][self.moves[-self.length][1]] = ' '              
            for i in range(1,self.length):
                self.board.board[self.moves[-i][0]][self.moves[-i][1]] = self.snakebody

    def movehead(self, ydir, xdir):
        self.ydir = ydir
        self.xdir = xdir
        self.head.y = self.head.y + ydir
        self.head.x = self.head.x + xdir 

    def movement(self, ydir, xdir):
        self.trim_and_place_body()
        self.movehead(ydir, xdir) 
        
        self.checkdeath()
        
        self.moves.append([self.head.y,self.head.x])
        self.check_and_replace_food()
        
        self.board.board[self.head.y][self.head.x] = self.head.head
        self.board.draw_board(self.length - 1)

gameboard = Board(boardlen ,boardwidth, framerate)
gamehead = Head(math.floor(gameboard.rows/2),math.floor(gameboard.columns/2))
gamesnake = Snake(gameboard, gamehead)
gameboard.placefood()
gameboard.draw_board(score)

def down():
    while downkey:
            gamesnake.movement(1,0)
def up():
    while upkey:
            gamesnake.movement(-1,0)
def left():
    while leftkey:
            gamesnake.movement(0,-1)
def right():
    while rightkey: 
            gamesnake.movement(0,1)

def keystrokes(Key):
    global downkey
    global upkey  # all of these had to be global for pynput
    global leftkey
    global rightkey
    if Key == Key.down and not gamesnake.ydir == -1: 
        if not downkey :  
            upkey = False
            leftkey = False #blocks all other threads and activates a thread for the given key
            rightkey = False            
            downkey = True
            Thread(target=down).start()
            # this repeats for all 3 other keystrokes no way around the repition,
            # pynput is being weird.
    elif Key == Key.up and not gamesnake.ydir == 1:

            if not upkey:
                downkey = False
                leftkey = False
                rightkey = False
                upkey = True
                Thread(target=up).start()
    elif Key == Key.left and not gamesnake.xdir == 1:
        if not leftkey:
            downkey = False
            upkey = False
            rightkey = False
            leftkey = True
            Thread(target=left).start()
    elif Key == Key.right and not gamesnake.xdir == -1:
        if not rightkey:
            downkey = False
            upkey = False
            leftkey = False
            rightkey = True
            Thread(target=right).start()
# how pynput reads keystrokes.
with Listener(on_press=keystrokes) as listener:
    listener.join()