[code-quality] Python skeletons: type hinting for third-party libraries

[Florian Weimer]

On 11/08/2013 11:08 AM, Vladimir Keleshev wrote:
>> You could also put asserts (and expressions which assert the presence of
>> certain attributes) in function bodies.
>
> Nice idea—that seems to give more flexibility, but (probably) makes it harder to implement.
>
> I would love to write:
>
>      assert hasattr(file_like, 'read') and hasattr(file_like, 'write')
>
> Or maybe:
>
>      assert file_like.read and file_like.write

I actually expect something like this:

     file_like.read(0)
     file_like.write("")

No assert statements, just straight-line code that is supposed to be 
easy to analyze.  If the analyzer cannot use the information that 
file_like must have a callable read attribute that takes an integer 
argument, it could still use the information that a "read" attribute 
must be present.

-- 
Florian Weimer / Red Hat Product Security Team