Python基础学习day09

'''print('step0')
try:
    print('step1')
    a = 3/0
    print('step2')
except baseException as e:
    print('step3')
    print('e')
    print(type(e))
print('end!!!')'''
while True:
    x = int(input('请输入一个数字'))
    print('输入数字:',x)
    if x==88:
        print('退出程序')
        break

while True:
    try:
        x = int(input('请输入一个数字'))
        print('输入数字:',x)
        if x==88:
           print('退出程序')
           break
    except baseException as e:
        print(e)
        print('异常，输入的不是一个数字')

# 测试try...多个except结构

try:
    a = input('请输入一个被除数')
    b = input('请输入一个除数')
    c = float(a)/float(b)
    print(c)
except ZeroDivisionError:
    print('异常，不能除以0')
except ValueError:
    print('异常，不能将字符串转化成数字')
except NameError:
    print('异常，变量不存在')
except baseException as e:
    print(e)

try:
    a = input('请输入一个被除数')
    b = input('请输入一个除数')
    c= float(a)/(b)
except baseException as e:
    print(e)
else:
    print(c)
finally:
    print('我是finall中的语句，无论发生异常与否，都执行！')
print('程序结束！')

# 测试finally
f = open('d:/a.txt','r')
content = f.readline()
print(content)
f.close()

with open('d:/a.txt','r')as f:
    content = f.readline()
    print(content)
print('程序执行结束')

# 测试trackback模块
import traceback
try:
    print('step1')
    num = 1/0
except:
    traceback.print_exc()
########异常信息输出到指定文件################
try:
    print('step1')
    num = 1/0
except:
    with open ('d:/a.txt','a')as f:
        traceback.print_exc(file=f)

# 测试自定义异常
class AgeError(Exception):    # 继承Exception
    def __init__(self,errorInfo):
        Exception.__init__(self)
        self.errorInfo = errorInfo
    def __str__(self):
        return "年龄错诶！"
#################测试代码#####################
if __name__=='__main__':   # 如果为Ture,则模块是作为独立文件运行，可以执行测试代码
    age = int(input("输入一个年龄："))
    if age<1 or age>150:
        raise AgeError(age)
    else:
        print('正常年龄：',age)