Pygame Collision Detection Error: 'collidedict()' vs. 'colliderect()'

The error you're encountering, "TypeError: first argument must be a dict", occurs because you are using the collidedict() method instead of the correct method colliderect().

The collidedict() method is designed to check if a rectangle collides with any other rectangles within a dictionary. However, in your code, you're trying to check if img_r collides with self.collision_area, which is a single rectangle, not a dictionary.

To resolve this error, simply replace the line:

if img_r.collidedict(self.collision_area):

with:

if img_r.colliderect(self.collision_area):

This will correctly check if the two rectangles, img_r and self.collision_area, are colliding.

Here's the corrected code snippet:

class Game():
    # ... other code ...
    def run(self):
        while True:
            # ... other code ...
            img_r = pygame.Rect(self.img_pos[0],self.img_pos[1],self.img.get_width(),self.img.get_height())
            if img_r.colliderect(self.collision_area):  # Corrected line
                pygame.draw.rect(self.screen,(0,0,0),self.collision_area)
            else:
                pygame.draw.rect(self.screen,(100,100,100),self.collision_area)
            # ... other code ...

By using colliderect(), you ensure that the collision detection works correctly between the two rectangles, eliminating the error and allowing your game to function as intended.