learning python ...

[Peter Otten]

On 23/05/2021 06:37, hw wrote:
> 
> Hi,
> 
> I'm starting to learn python and have made a little example program 
> following a tutorial[1] I'm attaching.
> 
> Running it, I'm getting:
> 
> 
> Traceback (most recent call last):
>    File "[...]/hworld.py", line 18, in <module>
>      print(isinstance(int, float))
> TypeError: isinstance() arg 2 must be a type or tuple of types
> 
> 
> I would understand to get an error message in line 5 but not in 18.  Is 
> this a bug or a feature?

It is a bug in your code (which you don't provide). Did you assign some 
value to float, e. g.:

 >>> float = 42.0
 >>> isinstance(int, float)
Traceback (most recent call last):
   File "<pyshell#313>", line 1, in <module>
     isinstance(int, float)
TypeError: isinstance() arg 2 must be a type or tuple of types

If you do not shadow the built-in you should get

 >>> isinstance(int, float)
False