Checking whether bool is a type

[Jan Decaluwe]

In my application I need to know whether bool is
available as a type (in Python2.3) or not. I just
realized I can use the following:

jand> python
Python 2.3c1 (#1, Jul 21 2003, 12:40:39)
[GCC 2.96 20000731 (Red Hat Linux 7.1 2.96-98)] on linux2
Type "help", "copyright" , "credits" or "license" for more information.[color=blue][color=green][color=darkred]
>>> type(bool) is type[/color][/color][/color]
True

jand> python2.2
Python 2.2.2 (#1, Oct 16 2002, 19:59:11)
[GCC 2.96 20000731 (Red Hat Linux 7.1 2.96-98)] on linux2
Type "help", "copyright" , "credits" or "license" for more information.[color=blue][color=green][color=darkred]
>>> type(bool) is type[/color][/color][/color]
0

Great isn't it ?! Not sure whether I should consider
this to be completely obvious or very deep ...

Regards, Jan

--
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Losbergenlaan 16, B-3010 Leuven, Belgium
mailto:jan@jand ecaluwe.com

http://jandecaluwe.com

[Martin v. Löwis]

Re: Checking whether bool is a type

Jan Decaluwe <jan@jandecaluw e.com> writes:
[color=blue]
> jand> python2.2
> Python 2.2.2 (#1, Oct 16 2002, 19:59:11)
> [GCC 2.96 20000731 (Red Hat Linux 7.1 2.96-98)] on linux2
> Type "help", "copyright" , "credits" or "license" for more information.[color=green][color=darkred]
> >>> type(bool) is type[/color][/color]
> 0
>
> Great isn't it ?! Not sure whether I should consider
> this to be completely obvious or very deep ...[/color]

Very obvious.

Python 2.2.1 (#1, Sep 10 2002, 17:49:17)
[GCC 3.2] on linux2
Type "help", "copyright" , "credits" or "license" for more information.[color=blue][color=green][color=darkred]
>>> bool[/color][/color][/color]
<built-in function bool>

bool is a function in Python 2.2.1+, not a type. It became a type only
in Python 2.3, see PEP 285.

Regards,
Martin

[Christos TZOTZIOY Georgiou]

Re: Checking whether bool is a type

On Sun, 27 Jul 2003 23:22:58 +0200, rumours say that Jan Decaluwe
<jan@jandecaluw e.com> might have written:
[color=blue]
>In my application I need to know whether bool is
>available as a type (in Python2.3) or not. I just
>realized I can use the following:[/color]
[color=blue][color=green][color=darkred]
>>> type(bool) is type[/color][/color][/color]

You might like to do this as an alternative:

def bool_is_type():
try:
return isinstance(bool , type)
except NameError:
return 0

to catch older python versions as well.
--
TZOTZIOY, I speak England very best,
Microsoft Security Alert: the Matrix began as open source.