snake.py

# -*- coding: utf-8 -*-

import keyboard
import os, keyboard, time, random

global clearVar
syst = os.name
if syst == 'nt':
    clearVar = "cls"
else:
    clearVar = "clear"
    
def gridSet(x, y, positions, apple, blocked):
    """
    Draws grid with all relevant characters.
    Starts at the top of the board and draws the board row by row using the coordinates "right" and "down"
    At each coordinate checks what mark should be printed and adds it to a line string which is printed for each row 
    """
    appleChar = 'Ó'
    spaceChar = ' '
    bottomChar = '▀'
    topChar = '▄'
    sideChar = '█'
    char = '#'
    blockedChar = '█'
    down = 0
    lineBreak = '\n'
    lines = [] #creates an array that will be joined later to form the play grid
    topRow = topChar*(x+2) #adds top border
    lines.append(topRow) #adds lines one by one to the grid array
    for height in range(y): #begins building grid by row
        right = 0
        down += 1
        line = ''
        for width in range(x+1): #goes through row unit by unit
            if right == 0 or right == x:
                line+=sideChar #adds right and left border
            right += 1
            if [right, down] in positions: #adds symbol for snake if coord is snake
                line+=char
            elif [right, down] == apple: #adds symbol for apple if coord is apple
                line+=appleChar
            elif [right, down] in blocked:
                line+=blockedChar
            else:
                line+=spaceChar #otherwise adds empy char
        lines.append(line) #adds line to the grid array
    bottomRow = bottomChar*(x+2)
    lines.append(bottomRow)
    grid = lineBreak.join(lines)#joins together the grid array with line breaks between lines
    print(grid) #print all lines at once to reduce flicker

def appleRandom(x,y):
    """
    Gives random coordinates for a new apple
    """
    appleX = random.randint(1,x)
    appleY = random.randint(1,y)
    apple = [appleX, appleY]
    return apple
    
def applePlacer(x,y,positions, blocked):
    """
    Places a new apple on the grid, tries to randomly place apples
    until the apple is in an unoccupied square
    """
    while True:
        apple = appleRandom(x,y)
        if apple not in positions and apple not in blocked:
            return apple

def moveChar(x,y,positions, direction, apple, score, blocked):
    """
    Moves the snake around the grid and keeps track of score
    """
    pos1 = [positions[len(positions)-1][0],positions[len(positions)-1][1]] #creates a copy coordinate of the front of player snake
    if direction == 'up': #moves the front coordinate in the relevant direction temporarily until conditions can be checked
        pos1[1] -= 1
    elif direction == 'down':
        pos1[1] +=1
    elif direction == 'left':
        pos1[0] -=1
    elif direction == 'right':
        pos1[0] +=1
    if pos1[0] >x: #checks if the front coordinate hit a wall
        pos1[0] = x
        return False
    if pos1[0]<1:
        pos1[0]=1
        return False
    if pos1[1] >y:
        pos1[1] = y
        return False
    if pos1[1]<1:
        pos1[1] = 1
        return False
    if pos1 in positions:#checks if the front coordinate hit the snake
        return False
    if pos1 in blocked: #checks if front coordinate hit a blocked section
        return False
    else:
        positions.append(pos1)#moves the front position permanently 
        if pos1 == apple: #checks if snake ate an apple, snake is lengthened by not removing back coordinate
            score += 100
            apple = applePlacer(x,y,positions, blocked)#places new apple
        else:
            positions = positions[1:]#if an apple is not eaten, the snake "moves" by removing the back coordinate after a new front coordinate is added
    return positions, direction, apple, score

def directionChanger(direction):
    """
    Checks if the player is changing direction by checking if the player is pressing a key
    """
    if keyboard.is_pressed('up'):
        if direction != 'down': #won't let player move in the opposite direction they are currently moving
            direction = 'up'
    elif keyboard.is_pressed('down'):
        if direction != 'up':
            direction = 'down'
    elif keyboard.is_pressed('left'):
        if direction != 'right':
            direction = 'left'
    elif keyboard.is_pressed('right'):
        if direction != 'left':
            direction = 'right'
    return direction

def levelSelect():
    """
    gives blocked spaced based on the player's level selection
    """

    level0 = [] #sets the blocked squares
    level1 = [[5,5],[5,6],[5, 4],[5,7],[5, 8],[5, 3],[14, 3],[14, 4],[14,5],[14,6],[14,7],[14,8]]
    levels = [level0, level1]#adds the level options to the level array
    while True:
        print('Which level would you like to play?')
        level = input('1. Open\n2. Parallel\n')
        try:
            a = int(level)
            try:
                return levels[a-1]
            except IndexError: #won't let player select level not in the options
                print('Invalid Selection')
                input()
                os.system(clearVar)
        except ValueError: #won't let player enter something other than a number
            print('Invalid Selection')
            input()
            os.system(clearVar)
        

def snake():
    """
    Main Game
    """
    hiScore = 0
    while True: #Start Game Loop, starts new games until the player wants to quit
        os.system(clearVar)
        print('+++++++++++++++++++++++++++++++')
        print()
        print('        ~~~~Snake!~~~~')
        print()
        print('+++++++++++++++++++++++++++++++')
        x, y = 18, 10 #sets board size

        pos1 = [x//2, y//2] #sets inital snake positions
        pos2 = [pos1[0]+1, pos1[1]]
        pos3 = [pos1[0]+2, pos1[1]]
        positions = [pos3, pos2, pos1]
        blocked = levelSelect()

        score = 0
        delay = 150
        startTurn = int(round(time.time()*1000))
        checked = 0
        direction = 'wait'

        os.system(clearVar)
        apple = applePlacer(x,y,positions, blocked) #places starting apple
        gridSet(x, y, positions, apple, blocked) #sets up initial grid
        print('Score:', score)
        print('High Score:', hiScore)

        while direction == 'wait': #waits to start game until player starts moving
            direction = directionChanger(direction)
            if direction == 'right': #can't move right because the snake starts facing left
                direction = 'wait'
            
        while True: #Main Game Loop. Cycles through drawing grid and getting player input
            if checked == False:
                directionTemp = directionChanger(direction) #Checks for player input until a valid change is detected
                if directionTemp != direction:
                    direction = directionTemp
                    checked = True #if the player changes direction, disables player input until the board is redrawn. Otherwise playe can run into themselves between screen draws
            currentTime = int(round(time.time()*1000))
            if currentTime > startTurn+delay: #Checks if the delay time has passed, if so starts the new turn
                checked = False
                direction = directionTemp
                try: #if moveChar returns False, will give a TypeError. This means a Game Over has happened
                    positions, direction, apple, score = moveChar(x, y, positions, direction, apple, score, blocked)
                    os.system(clearVar)
                    gridSet(x, y, positions, apple, blocked)
                    print('Score:', score)
                    print('High Score:', hiScore)
                    startTurn = int(round(time.time()*1000)) #sets the start time for the turn
                except TypeError:
                    print('Game Over!')
                    if score >hiScore:
                        hiScore = score
                        print('New High Score!')
                    input()
                    break

        print('Would you like to play again? y/n') #prompt player to play again if they lose
        again = input()
        if again == 'n':
            print('Bye!')
            input()
            break











def main():
	snake() 
if __name__ == "__main__":
     main()