Checking whether type is None
David Raymond
David.Raymond at tomtom.com
Tue Jul 24 15:56:54 EDT 2018
https://docs.python.org/3.7/library/constants.html
"None
The sole value of the type NoneType..."
"x is None" and "type(x) is type(None)" are equivalent because of that.
I think though that the better way to do the first tests would be to use isinstance
https://docs.python.org/3.7/library/functions.html#isinstance
isinstance({}, dict)
isinstance(3, int)
And I suppose if you really wanted:
isinstance(None, type(None))
-----Original Message-----
From: Python-list [mailto:python-list-bounces+david.raymond=tomtom.com at python.org] On Behalf Of Tobiah
Sent: Tuesday, July 24, 2018 3:33 PM
To: python-list at python.org
Subject: Checking whether type is None
Consider:
>>> type({}) is dict
True
>>> type(3) is int
True
>>> type(None) is None
False
Obvious I guess, since the type object is not None.
So what would I compare type(None) to?
>>> type(None)
<type 'NoneType'>
>>> type(None) is NoneType
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
NameError: name 'NoneType' is not defined
I know I ask whether:
>>> thing is None
but I wanted a generic test.
I'm trying to get away from things like:
>>> type(thing) is type(None)
because of something I read somewhere preferring
my original test method.
Thanks
--
https://mail.python.org/mailman/listinfo/python-list
More information about the Python-list
mailing list