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Groups > comp.lang.python > #9065

Re: Does hashlib support a file mode?

Date 2011-07-07 21:32 -0500
From Andrew Berg <bahamutzero8825@gmail.com>
Subject Re: Does hashlib support a file mode?
References (4 earlier) <0cd66788-5603-421e-82fb-fa3ac089711c@u42g2000yqm.googlegroups.com> <mailman.740.1310045106.1164.python-list@python.org> <6218f9fc-2155-4f31-aa07-fe2caadac190@y30g2000yqb.googlegroups.com> <mailman.741.1310047140.1164.python-list@python.org> <4e166165$0$29983$c3e8da3$5496439d@news.astraweb.com>
Newsgroups comp.lang.python
Message-ID <mailman.766.1310092389.1164.python-list@python.org> (permalink)

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On 2011.07.07 08:46 PM, Steven D'Aprano wrote:
> None is not a type, it is an instance.
>
> >>> isinstance(None, type)  # is None a type?
> False
> >>> isinstance(None, type(None))  # is None an instance of None's type?
> True
>
> So None is not itself a type, although it *has* a type:
>
> >>> type(None)
> <type 'NoneType'>
> >>> isinstance(type(None), type)  # is NoneType itself a type?
> True
I worded that poorly. None is (AFAIK) the only instance of NoneType, but
I should've clarified the difference.
> The is operator does not compare types, it compares instances for identity.
> There is no need for is to ever care about the type of the arguments --
> that's just a waste of time, since a fast identity (memory location) test
> is sufficient.
"Compare" was the wrong word. I figured the interpreter doesn't
explicitly compare types, but obviously identical instances are going to
be of the same type.

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Thread

Re: Does hashlib support a file mode? Carl Banks <pavlovevidence@gmail.com> - 2011-07-06 13:25 -0700
  Re: Does hashlib support a file mode? Phlip <phlip2005@gmail.com> - 2011-07-06 14:07 -0700
    Re: Does hashlib support a file mode? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-07-07 09:16 +1000
      Re: Does hashlib support a file mode? Andrew Berg <bahamutzero8825@gmail.com> - 2011-07-07 07:50 -0500
        Re: Does hashlib support a file mode? Phlip <phlip2005@gmail.com> - 2011-07-07 06:11 -0700
          Re: Does hashlib support a file mode? Andrew Berg <bahamutzero8825@gmail.com> - 2011-07-07 08:24 -0500
            Re: Does hashlib support a file mode? Phlip <phlip2005@gmail.com> - 2011-07-07 06:39 -0700
              Re: Does hashlib support a file mode? Andrew Berg <bahamutzero8825@gmail.com> - 2011-07-07 08:58 -0500
                Re: Does hashlib support a file mode? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-07-08 11:46 +1000
                Re: Does hashlib support a file mode? Andrew Berg <bahamutzero8825@gmail.com> - 2011-07-07 21:32 -0500
                Re: Does hashlib support a file mode? Phlip <phlip2005@gmail.com> - 2011-07-07 20:26 -0700
                Re: Does hashlib support a file mode? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-07-08 17:42 +1000
                Re: Does hashlib support a file mode? Phlip <phlip2005@gmail.com> - 2011-07-08 06:03 -0700
                Re: Does hashlib support a file mode? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-07-09 14:44 +1000

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