Type specified in python. Throw exceptions

Error in class type judgment(Exception):
    def __init__(self,ideal,reality): super(Exception, self).__init__(str(ideal)+'Even though the shape was good'+str(reality)+'The mold was passed')
class type is:
    def __init__(self,Mold): self.Mold=Mold
Judgment whether it is def(self,instance):
        if isinstance(instance, self.Mold): return instance
        else:error in raise type judgment(self.Mold.__name__, type(instance).__name__)

Write, foo = Determine if type is (hoge). (Var) If you write It will check if var is of type hoge. If var is of type hoge, do nothing, If it is not of type hoge, throw an exception.

Error in class type judgment(Exception):
    def __init__(self,ideal,reality): super(Exception, self).__init__(str(ideal)+'Even though the shape was good'+str(reality)+'The mold was passed')
class type is:
    def __init__(self,Mold): self.Mold=Mold
Judgment whether it is def(self,instance):
        if isinstance(instance, self.Mold): return instance
        else:error in raise type judgment(self.Mold.__name__, type(instance).__name__)        

class dog:
    pass
class cat:
    pass

def Put on the collar and go outside(Dog):
The type is(dog).Judgment(Dog)
    print('It's a walk!')

print("1st");Put on the collar and go outside(dog())
print("2nd");Put on the collar and go outside(Cat())

Is as follows.

1st
It's a walk!
2nd
Traceback (most recent call last):
  File "D:\sd_First half of 4 years\First half of 4 years\SUDAP3_-1\cgi-bin\Typer.py", line 19, in <module>
    print("2nd");Put on the collar and go outside(Cat())
  File "D:\sd_First half of 4 years\First half of 4 years\SUDAP3_-1\cgi-bin\Typer.py", line 15,in Put on the collar and go outside
The type is(dog).Judgment(Dog)
  File "D:\sd_First half of 4 years\First half of 4 years\SUDAP3_-1\cgi-bin\Typer.py", line 7,Judgment whether in
    else:error in raise type judgment(self.Mold.__name__, type(instance).__name__)
Error in type determination:The dog type was good, but the cat type was handed over