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Re: I am never going to complain about Python again

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On 2013-10-10, Roy Smith <roy@panix.com> wrote:
> In article <52562ee3$0$2931$c3e8da3$76491128@news.astraweb.com>,
>  Steven D'Aprano <steve@pearwood.info> wrote:
>
>> Just came across this little Javascript gem:
>> 
>> ",,," == Array((null,'cool',false,NaN,4));
>> 
>> => evaluates as true
>> 
>> http://wtfjs.com/2011/02/11/all-your-commas-are-belong-to-Array
>> 
>> I swear, I am never going to complain about Python again.
>
> I've just finished reading JavaScript: The Good Parts, by Douglas 
> Crockford (now I'm working on the harder part of re-reading it slowly, 
> to make sure I really understand it).  Anybody who is forced to work 
> with javascript should read this book.  It's the K&R of JS.
>
> Anyway, one of the pieces of advice he gives is to pretend that == 
> doesn't exist, and always use ===.  PHP suffers from much the same 
> problem.
>
> BTW, here's a Python equality oddity:
>
>>>> r = 0.0
>>>> c = 0 + 0j
>>>> r == c
> True
>>>> int(r) == int(c)
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> TypeError: can't convert complex to int
>
> If x == y, then f(x) should also equal f(y).  More
> specifically, if x == y, and x is in the domain of f(), then y
> should also be in the domain of f().

Mixed arithmetic always promotes to the wider type (except in
the case of complex numbers (Ha!)).

r == c is equivalent to r == abs(c), which returns the magintude
of the complex number.

I wonder why it was deemed reasonable to do that but not for the
float constructor to do the same, or even int.

> BTW, one of the earliest things that turned me on to Python was
> when I discovered that it uses j as the imaginary unit, not i.
> All right-thinking people will agree with me on this.

On top of the engineering origin, j is more noticeable.

-- 
Neil Cerutti

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I am never going to complain about Python again Steven D'Aprano <steve@pearwood.info> - 2013-10-10 04:36 +0000
  Re: I am never going to complain about Python again Chris Angelico <rosuav@gmail.com> - 2013-10-10 15:50 +1100
  Re: I am never going to complain about Python again Chris Rebert <clp2@rebertia.com> - 2013-10-09 22:26 -0700
  Re: I am never going to complain about Python again Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-10 06:39 +0100
  Re: I am never going to complain about Python again Christian Gollwitzer <auriocus@gmx.de> - 2013-10-10 08:41 +0200
  Re: I am never going to complain about Python again "Frank Millman" <frank@chagford.com> - 2013-10-10 10:23 +0200
  Re: I am never going to complain about Python again MRAB <python@mrabarnett.plus.com> - 2013-10-10 12:10 +0100
  Re: I am never going to complain about Python again Tim Chase <python.list@tim.thechases.com> - 2013-10-10 06:43 -0500
  Re: I am never going to complain about Python again "Frank Millman" <frank@chagford.com> - 2013-10-10 13:44 +0200
  Re: I am never going to complain about Python again Roy Smith <roy@panix.com> - 2013-10-10 09:09 -0400
    Re: I am never going to complain about Python again Neil Cerutti <neilc@norwich.edu> - 2013-10-10 15:51 +0000
      Re: I am never going to complain about Python again Rotwang <sg552@hotmail.co.uk> - 2013-10-10 16:57 +0100
        Re: I am never going to complain about Python again MRAB <python@mrabarnett.plus.com> - 2013-10-10 17:10 +0100
          Re: I am never going to complain about Python again Neil Cerutti <neilc@norwich.edu> - 2013-10-10 17:48 +0000
            Re: I am never going to complain about Python again Ian Kelly <ian.g.kelly@gmail.com> - 2013-10-10 12:35 -0600
              Re: I am never going to complain about Python again Neil Cerutti <neilc@norwich.edu> - 2013-10-10 18:49 +0000
            Re: I am never going to complain about Python again Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-10-10 20:47 +0100
              Re: I am never going to complain about Python again Neil Cerutti <neilc@norwich.edu> - 2013-10-10 19:54 +0000
            Re: I am never going to complain about Python again Cameron Simpson <cs@zip.com.au> - 2013-10-11 08:52 +1100
            Re: I am never going to complain about Python again Roy Smith <roy@panix.com> - 2013-10-10 20:07 -0400
              Is this the room for an argument? John Ladasky <john_ladasky@sbcglobal.net> - 2013-10-10 21:26 -0700
                Re: Is this the room for an argument? Roy Smith <roy@panix.com> - 2013-10-11 09:49 -0400
            Re: I am never going to complain about Python again Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-10-11 02:23 +0000
              Re: I am never going to complain about Python again Neil Cerutti <neilc@norwich.edu> - 2013-10-11 12:31 +0000
    Re: I am never going to complain about Python again Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-10-10 20:09 -0400
    Re: I am never going to complain about Python again Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-10-11 02:08 +0000
      Re: I am never going to complain about Python again Joshua Landau <joshua@landau.ws> - 2013-10-11 09:17 +0100
        Re: I am never going to complain about Python again Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-10-11 09:11 +0000
          Re: I am never going to complain about Python again Chris Angelico <rosuav@gmail.com> - 2013-10-11 20:52 +1100
          Re: I am never going to complain about Python again Joshua Landau <joshua@landau.ws> - 2013-10-11 17:56 +0100

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