does lack of type declarations make Python unsafe?

David Abrahams david.abrahams at rcn.com
Mon Jun 30 01:13:09 CEST 2003


david.abrahams at rcn.com (David Abrahams) wrote in message news:<ea97dfd9.0306290730.137c6837 at posting.google.com>...

> Alex Martelli <aleax at aleax.it> writes:
> 
> > In Python one generally identifies (just as informally) a container as
> > "an object which has a length" (using "length", perhaps a suboptimal
> > choice of wording, to mean "number of items currently contained") and
> > simultaneously express both 'c is a container' and 
> > 'that container is not empty' by
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
Sorry, I missed that.

> >
> >     assert len(c)
> 
> That understanding of "containerness" is, AFAICT, not universally held
> among Pythonistas by any means.  

I still stand by the above.

> Good thing too, probably: it looks
> like there is no such thing as an empty container:
> 
>      >>> assert len([])
>      Traceback ...

But that example was obviously just wrong.

-Ddave




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