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.

type(bool) is type 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. type(bool) is type

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:ja*@jandecaluwe.com
http://jandecaluwe.com

[Martin v. Löwis]

Jan Decaluwe <ja*@jandecaluwe.com> writes:

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.

type(bool) is type 0

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

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.

bool

<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]

On Sun, 27 Jul 2003 23:22:58 +0200, rumours say that Jan Decaluwe
<ja*@jandecaluwe.com> might have written:

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:

type(bool) is type

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.