Pygame Smooth Movement Example

import pygame

class KeyState:
    def __init__(self):
        self.update()

    def __call__(self, *keys):
        count = len(keys)
        if count == 1:
            return self.pressed[keys[0]]
        elif count > 1:
            return any([self.pressed[k] for k in keys])

    def update(self):
        self.pressed = pygame.key.get_pressed()

class Display:
    def __init__(self, caption, width, height, flags=0, fps=60):
        pygame.display.set_caption(caption)
        self.surface = pygame.display.set_mode((width, height), flags)
        self.rect = self.surface.get_rect()
        self.clock = pygame.Clock()
        self.running = True
        self.delta = 0
        self.fps = fps

    def flip(self):
        if self.running:
            pygame.display.flip()
            # For Smooth Movement
            self.delta = self.clock.tick(self.fps) / 1000

class Square(pygame.sprite.Sprite):
    def __init__(self, image, center, speed):
        super().__init__()
        self.image = image
        self.rect = image.get_rect(center=center)
        self.center = pygame.Vector2(center)
        self.speed = speed

    def move(self, movement, delta):
        self.center += movement * delta * self.speed
        self.rect.center = self.center

class ImageHandler:
    def __init__(self):
        self.square = pygame.Surface((50, 50))
        self.square.fill('dodgerblue')

class Target:
    def __init__(self, sprite):
        self.vector = pygame.Vector2()
        # Center is a weak reference.
        self.center = sprite.center
        self.sprite = sprite
        self.target = None

    def is_done(self):
        return self.vector.length() == 0

    def set(self, position):
        self.target = position
        self.vector = (position - self.center).normalize()

    def update(self, delta):
        if self.target:
            self.sprite.move(self.vector, delta)
            if self.vector.x < 0:
                if self.sprite.center.x <= self.target[0]:
                    self.vector.x = 0
                    self.center.x = self.target[0]
            elif self.vector.x > 0:
                if self.center.x >= self.target[0]:
                    self.vector.x = 0
                    self.center.x = self.target[0]

            if self.vector.y < 0:
                if self.sprite.center.y <= self.target[1]:
                    self.vector.y = 0
                    self.center.y = self.target[1]
            elif self.vector.y > 0:
                if self.center.y >= self.target[1]:
                    self.vector.y = 0
                    self.center.y = self.target[1]

            if self.is_done():
                self.target = None

class Game:
    def __init__(self):
        self.display = Display("Example", 600, 600)
        self.image = ImageHandler()
        self.key = KeyState()
        self.square = Square(self.image.square, self.display.rect.center, 80)
        self.sprites = pygame.sprite.Group(self.square)
        self.target = Target(self.square)

    def movement(self):
        self.key.update()
        direction = pygame.Vector2()
        if self.key(pygame.K_UP, pygame.K_w):
            direction.y -= 1

        if self.key(pygame.K_DOWN, pygame.K_s):
            direction.y += 1

        if self.key(pygame.K_LEFT, pygame.K_a):
            direction.x -= 1

        if self.key(pygame.K_RIGHT, pygame.K_d):
            direction.x += 1

        if direction.length() > 0:
            # Real World Movement
            direction.normalize_ip()
            self.square.move(direction, self.display.delta)

    def loop(self):
        while self.display.running:
            for event in pygame.event.get():
                if event.type == pygame.MOUSEBUTTONDOWN:
                    if event.button == 1:
                        self.target.set(event.pos)
                elif event.type == pygame.QUIT:
                    self.display.running = False

            self.target.update(self.display.delta)
            if self.target.is_done():
                self.movement()

            self.display.surface.fill('black')
            self.sprites.draw(self.display.surface)
            self.display.flip()

pygame.init()
game = Game()
game.loop()
pygame.quit()