python基础之错误和异常处理

import Exception
# except 在捕获错误异常的时候 是要根据具体的错误类型来捕获的
# 用一个块 可以捕获多个不同类型的异常
# EXception 可以捕获所有异常 当对出现的问题或者错误不确定的情况下 可以使用此种
print(dir(Exception))
try:
 # print(b)  #捕获逻辑的代码
 li=[1,2,3,4]
 print(li[10])
 pass
except NameError as msg:
 # 捕获到的错误 才会在这里执行
 print(msg)
 pass
except IndexError as msg:
 print(msg)
print('初次接触异常')
print('HAHAHAHAHHAHAHAH')

try:
 # print(b)  #捕获逻辑的代码
 # li=[1,2,3,4]
 # print(li[10])
 a=10/0
 pass
except NameError as msg:
 # 捕获到的错误 才会在这里执行
 print(msg)
 pass
except IndexError as msg:
 print(msg)
 pass
except ZeroDivisionError as msg:
 print(msg)
print('初次接触异常')
print('HAHAHAHAHHAHAHAH')

try:
 print(b)  #捕获逻辑的代码
 # li=[1,2,3,4]
 # print(li[10])
 # a=10/0
 pass
# except NameError as msg:
#  # 捕获到的错误 才会在这里执行
#  print(msg)
#  pass
# except IndexError as msg:
#  print(msg)
#  pass
# except ZeroDivisionError as msg:
#  print(msg)
#  pass
except Exception as msg:
 print(msg)
 pass
print('初次接触异常')
print('HAHAHAHAHHAHAHAH')

def A(s):
 return 10/int(s)
 pass
def B(s):
 return A(s)*2
def main():
 try:
  B('0')
  pass
 except Exception as msg:
  print(msg)
  pass
 pass
main()
# 不需要在每个可能出错的地方去捕获,只要在合适的层次去捕获错误就可以了 这样的话 就大大减少我们写try----exception的麻烦
# 异常的抛出机制
#如果在运行时发生异常 解释器会查找相应的异常捕获类型
#如果在当前函数里面没有找到的话 它会将异常传递给上层的调用函数
#如果在最外层 没有找到的话 解释器就会退出 程序down掉

class ToolongmyException(Exception): #自定义异常
 def __init__(self,leng):
  '''
:param leng:长度
  '''
  self.len=leng
 pass
 def __str__(self):
  return '您输入的数据长度是'+str(self.len)+'已经超过长度了'
 pass
def name_Test():
 name=input('请输入姓名：')
 if len(name)>5:
  raise ToolongmyException(len(name))#抛出异常
 else:
  print(name)
  pass
 pass
name_Test()

class ToolongmyException(Exception): #自定义异常
 def __init__(self,leng):
  '''
:param leng:长度
  '''
  self.len=leng
 pass
 def __str__(self):
  return '您输入的数据长度是'+str(self.len)+'已经超过长度了'
 pass
def name_Test():
 name=input('请输入姓名：')
 try:
  if len(name)>5:
raise ToolongmyException(len(name))#抛出异常
  else:
print(name)
pass
 except ToolongmyException as result:
  print(result)
  pass
 finally:
  print('执行完毕了')
 pass
name_Test()