Acquaintance python: Exception Handling

Exception handling basic syntax:

try:
    pass
except Exception,ex:
    pass

Common Error type:

AttributeError attempts to access an object, not the property. For example foo.x, but no attribute foo X 
IOError input / output is abnormal (substantially is unable to open the file) 
ImportError package or module can not be introduced into the (substantially name or path error problem) 
one kind IndentationError syntax errors, the code does not indented 
IndexError subscript index out of sequence boundaries, such as a list of only three elements x, is trying to access x [ . 5 ] 
a KeyError attempts to access the dictionary does not exist in the bond 
the KeyboardInterrupt the Ctrl + C is pressed 
variable NameError use a yet undefined 
SyntaxError Python code is illegal, the code does not compile 
TypeError incoming object type does not comply with the requirements of 
UnboundLocalError attempt to access a local variable has not been set, basically due to a global variable otherwise the same name leads you to think that it is being accessed 
ValueError pass a the caller does not expect value, even if the type of value is correct. For example, a character string you want to convert to digital: n- = ' ABC ' int (n-)

Single abnormal crawl:

= {Data ' ID ' : 123 }
 the try : 
    Data [ ' name ' ]
 the except a KeyError AS E:
     Print ( ' no such Key: ' , E)

Multiple exceptions crawl:

In this way if the first wrong, it will not perform exception processing behind.

= {Data ' ID ' : 123 } 
List = [1,2 ]
 # processes only KeyError, IndexError not be processed later. 
the try : 
    Data [ ' name ' ] 
    List [ . 3 ]
 the except a KeyError AS E:
     Print ( ' no such Key: ' , E)
 the except IndexError AS E:
     Print ( ' list operation error: ' , E)

More of the specified exceptions, returns the same result:

# More specified exceptions, returns the same result. 
# As long as there have been any one of which would be returned. 
= {Data ' ID ' : 123 } 
List = [1,2 ]
 the try : 
    Data [ ' name ' ] 
    List [ . 3 ]
 the except (IndexError, a KeyError) AS E:   # when specified error occurred, execution. 
    Print ( ' emerged specified error. ' )

 

Universal Exception:

　No matter what mistakes, can obtain. Not recommended to start is to use.

= {Data ' ID ' : 123 } 
List = [1,2 ] 

the try : 
    Data [ ' name ' ] 
    List [ . 3 ]
 the except Exception AS E:   # fetch any abnormality 
    Print ( " error occurred. ' )

 

Other structural abnormalities:

　When except Exception unspecified error, execution.

　When else is correct, run

　finally Whether there is nothing wrong, it is executed.

= {Data ' ID ' : 123 } 
List = [1,2 ] 

the try :
     # Data [ 'name'] 
    List [ ' ABC ' ] 
    n- . 1 =
 the except (IndexError, a KeyError) AS E:   # when specified error occurred, carried out. 
    Print ( ' occurred specified error. ' )
 the except Exception AS E:   # when a non-specified error occurred, execution. 
    Print ( ' there was an unspecified error Unknown error! ' , E)
 the else :   # no error, execution. 
    Print ( 'Everything is normal, no errors. ' )
 A finally :   # Whether there is nothing wrong, it is executed. 
    Print ( ' Whether there is nothing wrong with the implementation of all this! ' )

Active trigger an exception:

the try :
     The raise Exception ( ' active trigger exception! ' )
 the except Exception AS E:
     Print (E)

Custom exception:

class MyExceptin (Exception):
     DEF  the __init__ (Self, MSG): 
        self.msg = MSG 
        
the try :
     The raise MyExceptin ( ' custom exception! ' )
 the except MyExceptin AS E:
     Print (E)