Testing for a list
Antun Karlovac
antun at antunkarlovac.com
Mon Mar 10 14:53:48 EST 2003
I guess you're right. For this particular application, I could just always have a
list, even if it's only got one item in it.
Me being lazy.
-Antun
> -----Original Message-----
> From: Thomas Wouters [mailto:thomas at xs4all.net]
> Sent: Monday, March 10, 2003 11:13 AM
> To: Antun Karlovac
> Cc: 'Brian Quinlan'; 'Mark McEahern'; python-list at python.org
> Subject: Re: Testing for a list
>
>
>
> What is a list ? Is a subclass of a list also a list ? What
> about a Python object that pretends to be a list ? Why do you
> need to check whether something is a list anyway ? If you're
> doing some kind of type-checking, it's usually better not to;
> instead, have your function blow up when trying to (say)
> index the passed-in would-be list, informing the programmer
> than one of their functions called your function with the
> wrong type of argument.
>
> If you really really really want to test for list-ness,
> don't; instead, use the recipe posted earlier that tests
> whether the object *acts* like a list.
>
> --
> Thomas Wouters <thomas at xs4all.net>
>
> Hi! I'm a .signature virus! copy me into your .signature file
> to help me spread!
>
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