Refactor snake game code for better readability

Author: google-labs-jules[bot]

GAMES/SNAKE_GAME/snake.py

@@ -1,61 +1,88 @@
 import random
 import curses
 
+# Constants
+INITIAL_SNAKE_LENGTH = 3
+SNAKE_HEAD_CHAR = curses.ACS_CKBOARD
+FOOD_CHAR = curses.ACS_PI
+TIMEOUT = 100
+
+def create_initial_snake(screen_width, screen_height):
+    snake_x = screen_width / 4
+    snake_y = screen_height / 2
+    return [[snake_y, snake_x - i] for i in range(INITIAL_SNAKE_LENGTH)]
+
+def create_food(snake, screen_width, screen_height):
+    food = None
+    while food is None:
+        new_food = [random.randint(1, screen_height - 1), random.randint(1, screen_width - 1)]
+        food = new_food if new_food not in snake else None
+    return food
+
+def move_snake(snake, key):
+    new_head = [snake[0][0], snake[0][1]]
+
+    if key == curses.KEY_DOWN:
+        new_head[0] += 1
+    elif key == curses.KEY_UP:
+        new_head[0] -= 1
+    elif key == curses.KEY_LEFT:
+        new_head[1] -= 1
+    elif key == curses.KEY_RIGHT:
+        new_head[1] += 1
+
+    snake.insert(0, new_head)
+
+def check_collision(snake, screen_height, screen_width):
+    if snake[0][0] in [0, screen_height] or snake[0][1] in [0, screen_width] or snake[0] in snake[1:]:
+        return True
+    return False
+
+def update_screen(window, snake, food, ate_food):
+    if not ate_food:
+        tail = snake.pop()
+        window.addch(int(tail[0]), int(tail[1]), " ")
+    window.addch(int(snake[0][0]), int(snake[0][1]), SNAKE_HEAD_CHAR)
+    if ate_food:
+        window.addch(food[0], food[1], FOOD_CHAR)
 
 def play_game():
-    s = curses.initscr()
+    screen = curses.initscr()
     curses.curs_set(0)
-    sh, sw = s.getmaxyx()
-    w = curses.newwin(sh, sw, 0, 0)
-    w.keypad(1)
-    w.timeout(100)
-
-    snk_x = sw / 4
-    snk_y = sh / 2
-    snake = [[snk_y, snk_x], [snk_y, snk_x - 1], [snk_y, snk_x - 2]]
+    screen_height, screen_width = screen.getmaxyx()
+    window = curses.newwin(screen_height, screen_width, 0, 0)
+    window.keypad(1)
+    window.timeout(TIMEOUT)
 
-    food = [sh / 2, sw / 2]
-    w.addch(int(food[0]), int(food[1]), curses.ACS_PI)
+    snake = create_initial_snake(screen_width, screen_height)
+    food = create_food(snake, screen_width, screen_height)
+    window.addch(int(food[0]), int(food[1]), FOOD_CHAR)
 
     key = curses.KEY_RIGHT
 
     while True:
-        next_key = w.getch()
+        next_key = window.getch()
         key = key if next_key == -1 else next_key
 
-        if snake[0][0] in [0, sh] or snake[0][1] in [0, sw] or snake[0] in snake[1:]:
+        if check_collision(snake, screen_height, screen_width):
             curses.endwin()
             quit()
 
-        new_head = [snake[0][0], snake[0][1]]
-
-        if key == curses.KEY_DOWN:
-            new_head[0] += 1
-        if key == curses.KEY_UP:
-            new_head[0] -= 1
-        if key == curses.KEY_LEFT:
-            new_head[1] -= 1
-        if key == curses.KEY_RIGHT:
-            new_head[1] += 1
-
-        snake.insert(0, new_head)
+        move_snake(snake, key)
 
-        if snake[0] == food:
-            food = None
-            while food is None:
-                nf = [random.randint(1, sh - 1), random.randint(1, sw - 1)]
-                food = nf if nf not in snake else None
-            w.addch(food[0], food[1], curses.ACS_PI)
-        else:
-            tail = snake.pop()
-            w.addch(int(tail[0]), int(tail[1]), " ")
+        ate_food = snake[0] == food
+        if ate_food:
+            food = create_food(snake, screen_width, screen_height)
 
-        w.addch(int(snake[0][0]), int(snake[0][1]), curses.ACS_CKBOARD)
+        update_screen(window, snake, food, ate_food)
 
 
-user_input = input("Do you want to play the snake game, type 'yes' or 'no': ").lower()
+def main():
+    user_input = input("Do you want to play the snake game, type 'yes' or 'no': ").lower()
+    if user_input == "yes":
+        play_game()
+    else:
+        quit()
 
-if user_input == "yes":
-    play_game()
-else:
-    quit()
+if __name__ == "__main__":
+    main()