Built-in functions and keyword arguments
Hendrik van Rooyen
mail at microcorp.co.za
Mon Oct 29 13:03:34 EDT 2007
"Tim Chase" <python.list at tim.thechases.com>
> > I think you are being a little bit unfair here: help(len) says:
> >
> > len(...)
> > len(object) -> integer
> >
> > Return the number of items of a sequence or mapping.
> >
> > which implies that the argument to len has the name 'object' (although in
> > fact it doesn't have a name).
>
> And to confound matters even further for the uninitiated,
>
> http://docs.python.org/lib/built-in-funcs.html#l2h-45
>
> says that it's "len(s)" instead (but "len(s=[])" doesn't work either)
Looks like a gotcha to me - its the difference between a keyword
(master = 42) and an assignment (s='I am a string')
You just can't do that - how is the parser supposed to know that
the second one is an assignment and not a keyword?
len([]) should work, though.
- Hendrik
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