typechecks: just say no! (was Re: Determining Types)

[Alex Martelli]

"Fredrik Lundh" <fredrik at pythonware.com> wrote in message
news:FC%k7.752$sn6.161080 at newsc.telia.net...
> Skip Montanaro wrote:
> > I suppose it might be the way you've written it, but I don't actually
call
> > an extra function to perform the comparison.  I just code the test
inline:
> >
> >     if type(var) is not types.StringType:
> >         var = str(var)
>
> oh, that's lame ;-)
>
> str does the same thing, but in C.  from the documentation:

...so an unconditional
    var = str(var)
is vastly preferable.  Agreed!


>     str(object)
>
>     Return a string containing a nicely printable representation
>     of an object. For strings, this returns the string itself.
>
> same goes for int(), float(), long(), and tuple() (but not list())

And that, of course, is because list is the only mutable
type out of this bunch.


Alex