第9章 异常处理及程序调试
1、实验目的和要求
（1）了解并掌握异常的概念
（2）了解并掌握异常处理语句：try...except语句、try...except...else语句、try...except...finally语句、使用raise语句抛出异常。
（3）了解并掌握程序调试的用法。
2、实验环境
笔记本与Python书本
3、实验过程
实例01 模拟幼儿园分苹果
步骤：在IDLE中创建一个名称为division_apple.py的文件，然后在该文件中定义一个模拟分苹果的函数division()，在该函数中，要求输入苹果的数量和小朋友的数量，然后应用除法算式计算分配的结果，最后调用division()函数
def division():
'''功能：分苹果'''
print("\n=================== 分苹果了 ===============\n")
apple = int(input("请输入苹果的个数："))
children = int(input("请输入来了几个小朋友："))
result = apple//children
remain =apple-result*children
if remain>0:
print(apple,"个苹果，平均分给",children,"个小朋友，每人分",result,"个，剩下",remain,"个。")
else:
print(apple,"个苹果，平均分给",children,"个小朋友，每人分",result,"个。")
if __name__=='__main__':
division()
实例02 模拟幼儿园分苹果（除数不能为0）
步骤：在IDLE中创建一个名称为division_apple_0.py的文件，然后将实例01的代码全部复制到该文件中，并且对“if __name__=='__main__':”语句下面的代码进行修改，应用try...except语句捕获执行division()函数可能抛出的ZeroDivisionError（除数为零）异常
def division():
'''功能：分苹果'''
print("\n=================== 分苹果了 ===============\n")
apple = int(input("请输入苹果的个数："))
children = int(input("请输入来了几个小朋友："))
result = apple//children
remain =apple-result*children
if remain>0:
print(apple,"个苹果，平均分给",children,"个小朋友，每人分",result,"个，剩下",remain,"个。")
else:
print(apple,"个苹果，平均分给",children,"个小朋友，每人分",result,"个。")
if __name__=='__main__':
try:
division()
except ZeroDivisionError:
print("\n出错了 ~_~ ——苹果不能被0个小朋友分！")
def division():
'''功能：分苹果'''
print("\n=================== 分苹果了 ===============\n")
apple = int(input("请输入苹果的个数："))
children = int(input("请输入来了几个小朋友："))
result = apple//children
remain =apple-result*children
if remain>0:
print(apple,"个苹果，平均分给",children,"个小朋友，每人分",result,"个，剩下",remain,"个。")
else:
print(apple,"个苹果，平均分给",children,"个小朋友，每人分",result,"个。")
if __name__=='__main__':
try:
division()
except ZeroDivisionError:
print("\n出错了 ~_~ ——苹果不能被0个小朋友分！")
except ValueError as e:
print("输入错误：",e)
实例03 模拟幼儿园分苹果（每个人至少分到一个苹果）
步骤：在IDLE中创建一个名称为division_apple_1.py的文件，然后将实例02的代码全部复制到该文件中，并且在第5行代码“children = int(input("请输入来了几个小朋友："))”的下方添加一个if 语句，实现当苹果的数量小于小朋友的数量时，应用raise语句抛出一个ValueError异常，接下来再在最后一行语句的下方添加except语句处理ValueError异常
def division():
'''功能：分苹果'''
print("\n=================== 分苹果了 ===============\n")
apple = int(input("请输入苹果的个数："))
children = int(input("请输入来了几个小朋友："))
if apple < children:
raise ValueError("苹果太少了，不够分……")
result = apple//children
remain =apple-result*children
if remain>0:
print(apple,"个苹果，平均分给",children,"个小朋友，每人分",result,"个，剩下",remain,"个。")
else:
print(apple,"个苹果，平均分给",children,"个小朋友，每人分",result,"个。")
if __name__=='__main__':
try:
division()
except ZeroDivisionError:
print("\n出错了 ~_~ ——苹果不能被0个小朋友分！")
except ValueError as e:
print("\n出错了 ~_~ ——",e)
实例04 模拟幼儿园分苹果（应用断言调试）
步骤：在IDLE中创建一个名称为division_apple_dug.py的文件，然后将实例01的代码全部复制到该文件中，并且在第5行代码“children =int(input("请输入来了几个小朋友："))”的下方添加一个assert语句，验证苹果的数量是否小于小朋友的数量
def division():
'''功能：分苹果'''
print("\n=================== 分苹果了 ===============\n")
apple = int(input("请输入苹果的个数："))
children = int(input("请输入来了几个小朋友："))
assert apple >= children ,"苹果不够分"
result = apple//children
remain =apple-result*children
if remain>0:
print(apple,"个苹果，平均分给",children,"个小朋友，每人分",result,"个，剩下",remain,"个。")
else:
print(apple,"个苹果，平均分给",children,"个小朋友，每人分",result,"个。")
if __name__=='__main__':
division()
def division():
'''功能：分苹果'''
print("\n=================== 分苹果了 ===============\n")
apple = int(input("请输入苹果的个数："))
children = int(input("请输入来了几个小朋友："))
assert apple >= children ,"苹果不够分"
result = apple//children
remain =apple-result*children
if remain>0:
print(apple,"个苹果，平均分给",children,"个小朋友，每人分",result,"个，剩下",remain,"个。")
else:
print(apple,"个苹果，平均分给",children,"个小朋友，每人分",result,"个。")
if __name__=='__main__':
try:
division()
except AssertionError as e:
print("\n输入有误：",e)
