Python__異常處理

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# aaaaaaaaa
# print(‘===>‘)

#語法錯誤
# if :pass
# def func:pass

#邏輯錯誤
# TypeError
# for i in 3:
# pass

# NameError
# aaaaa

# ValueError
# int(‘asdfsadf‘)

#IndexError
# l=[1,2]
# l[1000]

#KeyError
# d={‘a‘:1}
# d[‘b‘]

# AttributeError
# class Foo:pass
#
# Foo.x

 

# try:
# f=open(‘a.txt‘)
# next(f)
# next(f)
# next(f)
# next(f)
# next(f)
# next(f)
# next(f)
# except StopIteration as e:
# pass
#
#
# print(‘====>‘)

 

# try:
# # aaaa
# print(‘==-==>1‘)
# l=[]
# l[3]
# print(‘==-==>2‘)
# d={}
# d[‘x‘]
# print(‘==-==>3‘)
# except NameError as e:
# print(e)
# except IndexError as e:
# print(e)
# except KeyError as e:
# print(e)

#
# try:
# # aaaa
# print(‘==-==>1‘)
# l=[]
# l[3]
# print(‘==-==>2‘)
# d={}
# d[‘x‘]
# print(‘==-==>3‘)
# except Exception as e:
# print(e)

 

# try:
# aaaa
# print(‘==-==>1‘)
# # l=[]
# # l[3]
# # print(‘==-==>2‘)
# # d={}
# # d[‘x‘]
# # print(‘==-==>3‘)
# except NameError as e:
# print(e)
# except IndexError as e:
# print(e)
# except KeyError as e:
# print(e)
# except Exception as e:
# print(e)
# else:
# print(‘在沒有錯誤的時候執行‘)
# finally:
# print(‘無論有無錯誤，都會執行‘)

 

# raise TypeError(‘----‘)

# class EgonException(BaseException):
# def __init__(self,msg):
# self.msg=msg
# def __str__(self):
# return ‘<%s>‘ %self.msg
#
# raise EgonException(‘egon 的異常‘)

 

# l=[1,2,3]
# assert len(l) > 3

#什麼時候用try ...except
#錯誤一定會發生，但是無法預知錯誤發生條件

Python__異常處理