本人2018年写的pygame图像处理代码，免费发给读者。

import pygame
from math import sin,cos,radians

class Durtle():
    """Durtle取名自Draw与turtle的组合，它是用来生成图像的"""
    def __init__(self,image,heading = 0,width=1,color=(0,0,0)):
        self.__pensize__ = width                          # 笔迹宽度,对应的是draw.circle的半径
        self.__color__ = color                            # rgb255颜色        
        self.__image__ = image                            # 在哪个图像上画 
        self.__heading__ = heading
        self.__imagerect__ = self.__image__.get_rect()    # 获取图像的rect,描述坐标与长高的        
        self.__width__ = self.__imagerect__.width         # 图像的宽
        self.__height__ = self.__imagerect__.height       # 图像的高
         
        self.x = self.__width__//2                        # 起始x坐标
        self.y = self.__height__//2                       # 起始y坐标

    def setheading(self,heading):
        """设定方向，以0度为向右，90度为向上，180度为向左，270度为向下"""
        self.__heading__ = heading
        
    def right(self,angle):
        """右转"""
        self.__heading__ = (self.__heading__ - angle) % 360
        
    def left(self,angle):
        """左转"""
        self.__heading__ = (self.__heading__ + angle) % 360
        
    def forward(self,step):
        """朝当前方向移动step像素"""
        if step == 0 :return
        length = abs(step)        
        k = length / step   
        for i in range(length):
          pygame.draw.circle(self.__image__,self.__color__,(int(self.x),int(self.y)),self.__pensize__)
          self.x = self.x + k * cos(radians(self.__heading__))
          self.y = self.y - k * sin(radians(self.__heading__))            
         
    def save(self,filename = "test_demo2.png"):
        pygame.image.save(self.__image__,filename)            
             

if __name__ == "__main__":
    
    image = pygame.Surface((1024,1024),pygame.SRCALPHA,32) #创建透明图像
    p =Durtle(image,30,2,(15,250,55))

    for i in range(36):
        p.forward(100)
        p.forward(-100)
        p.right(10)
        
    p.save()