User defined exception class in python

Today i learned something about user defined exception class in python and posting  in my blog so that i can remember in future :)


This is my check_age.py file

from own_Exeption import teenageException,kidException,childException

def age(x):
        try:
                if( x >= 14 ) and (x <= 19):
                        raise teenageException
                elif(x >= 8 ) and (x <= 13) :
                        raise kidException
                elif(x >= 2 ) and (x <= 7) :
                        raise childException
                #else:
                #       print("Ags is : "+str(x))
        except teenageException:
                print("WARNING : You are teenage not allowed here")
        except kidException:
                print("WARNING: you are kid not allowed here")
        except childException:
                print("WARNING: you are child not allowed here")
        else:
                print("INFO: You are the right age {} adult person".format(x))
        finally:
                print("INFO: End of the try/except block")

age(3)
age(17)
age(21)

Here is my user defined exception class

cat own_Exeption.py

class teenageException(Exception):
        pass
class kidException(Exception):
        pass
class childException(Exception):
        pass  

Initially i tried without try/except block. it seems like execution getting halt as soon as raise block invoked. So i tried with try/except block to catch the respective and print the warning message. here is my output.

       

WARNING: you are child not allowed here
INFO: End of the try/except block
WARNING : You are teenage not allowed here
INFO: End of the try/except block
INFO: You are the right age 21 adult person
INFO: End of the try/except block


       
 


i could also use raise statement inside except block like below to halt the code from further execution

       

from own_Exeption import teenageException,kidException,childException

def age(x):
        try:
                if( x >= 14 ) and (x <= 19):
                        raise teenageException
                elif(x >= 8 ) and (x <= 13) :
                        raise kidException
                elif(x >= 2 ) and (x <= 7) :
                        raise childException
                #else:
                #       print("Ags is : "+str(x))
        except teenageException:
                print("WARNING : You are teenage not allowed here")
                raise teenageException
        except kidException:
                print("WARNING: you are kid not allowed here")
                raise kidException
        except childException:
                print("WARNING: you are child not allowed here")
                raise childException
        else:
                print("INFO: You are the right age {} adult person".format(x))
        finally:
                print("INFO: End of the try/except block")

age(3)
age(17)
age(21)


       
 

This  will stop execution  withing first error.

       

WARNING: you are child not allowed here
INFO: End of the try/except block
Traceback (most recent call last):
  File "sat1.py", line 27, in 
    age(3)
  File "sat1.py", line 21, in age
    raise childException
own_Exeption.childException