Correct type for a simple "bag of attributes" namespace object
Albert-Jan Roskam
fomcl at yahoo.com
Sun Aug 3 07:14:12 EDT 2014
----- Original Message -----
> From: Albert-Jan Roskam <fomcl at yahoo.com.dmarc.invalid>
> To: Terry Reedy <tjreedy at udel.edu>; "python-list at python.org" <python-list at python.org>
> Cc:
> Sent: Sunday, August 3, 2014 11:17 AM
> Subject: Re: Correct type for a simple "bag of attributes" namespace object
<snip>
>>>>> Right. The 'types' module provides a SimpleNamespace
> class
>> for the
>>>>> common "bag of attributes" use case::
>>>>>
>>>>> >>> import types
>>>>> >>> foo = types.SimpleNamespace()
>>>>> >>> foo.x = 3
>>>>> >>> foo
>>>>> namespace(x=3)
>>>>
>>>> This is too much for children (& beginners).
>>>>
>>>> But perhaps what I should be asking for is for a new built-in that
> does
>> what types.SimpleNamespace() does, so that without any import you can
> write,
>> say,
>>>>
>>>> foo = namespace(a=1, b=2)
>>>> # or
>>>> bar = namespace()
>>>> bar.a = 1
>
> I find the following obscure (to me at least) use of type() useful exactly for
> this "bag of attributes" use case:
>>>> employee = type("Employee", (object,), {})
>>>> employee.name = "John Doe"
>>>> employee.position = "Python programmer"
>>>> employee.name, employee.position, employee
> ('John Doe', 'Python programmer', <class
> '__main__.Employee'>)
>
>>>> details = dict(name="John Doe", position="Python
> programmer")
>>>> employee = type("Employee", (object,), details)
>>>> employee.name, employee.position, employee
> ('John Doe', 'Python programmer', <class
> '__main__.Employee'>)
PS to my previous mail: class() can (should?) be used here to do the exact same thing but it feels a little like "Getting your car [OOP] just because you need an ashtray [bundled items]". :-)
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