上海交通大学python程序设计课程.pptx

面向对象思想和编程;2;3;4;5;6;7;8;9;10;11;12;13;14;15;16;17;类的定义;实例变量(1);实例变量(2);21;实例创建(1);实例创建(2);例:实例创建(1);例:实例创建(2);方法调用;方法调用图示;编程案例:模拟炮弹飞行(1);编程案例:模拟炮弹飞行(2);编程案例:模拟炮弹飞行(3);from math import pi, sin, cos def main(): angle = input(Enter the launch angle: ) vel = input(Enter the initial velocity: ) h0 = input(Enter the initial height : ) time = input(Enter the time interval : ) radians = (angle * pi)/180.0 xpos = 0 ypos = h0 xvel = vel * cos(radians) yvel = vel * sin(radians) while ypos = 0: xpos = xpos + time * xvel yvel1 = yvel - 9.8 * time ypos = ypos + time * (yvel + yvel1)/2.0 yvel = yvel1 print \nDistance traveled: %0.1f meters. % (xpos) main() 这个版本是流水帐式的,没有章法结构. 程序不长,倒有10个变量,为理解程序需要跟踪这10个数据的变化. ;编程案例:模拟炮弹飞行(4);编程案例:模拟炮弹飞行(5);from math import pi, sin, cos class Projectile: def __init__(self, angle, velocity, height): self.xpos = 0.0 self.ypos = height theta = pi * angle / 180.0 self.xvel = velocity * cos(theta) self.yvel = velocity * sin(theta) def update(self, time): self.xpos = self.xpos + time * self.xvel yvel1 = self.yvel - 9.8 * time self.ypos = self.ypos + time * (self.yvel + yvel1) / 2.0 self.yvel = yvel1 def getY(self): return self.ypos def getX(self): return self.xpos;编程案例:模拟炮弹飞行(6);类与模块化;例:学生信息处理系统;如何表示任意复杂的数据;39;40;41;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modify Parameters;Functions that Modif