Re: dict to boolean expression, how to?

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From	Ned Batchelder <ned@nedbatchelder.com>
Subject	Re: dict to boolean expression, how to?
Date	Fri, 01 Aug 2014 10:29:10 -0400
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On 8/1/14 8:45 AM, Alex van der Spek wrote:
> With a dict like so:
>
> cond = {'a': 1, 'b': 1, 'c': 1,
>          'A': 0, 'B', 0, 'C':0}
>
> how would you make a boolean expression like this:
>
> bool = (('a' == 1) & ('A' == 0) |
>          ('b' == 1) & ('B' == 0) |
>          ('c' == 1) & ('C' == 0))
>
> The fact that lowercase and uppercase keys are stringed together with & is
> intentional albeit the actual condition is a bit more tricky.
>
> I've tried several approaches using eval() on a string built from the dict
> but landed with just spelling it out literally.
>
>
> Any pointers welcome.
> Alex
>

Are you looking for this?

     bool = (
         (cond['a'] == 1 and cond['A'] == 0) or
         (cond['b'] == 1 and cond['B'] == 0) or
         (cond['c'] == 1 and cond['C'] == 0)
     )

If so, what's wrong with that expression exactly?  I'm not sure how eval 
could enter into it, so I feel like I'm missing something.

-- 
Ned Batchelder, http://nedbatchelder.com

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Thread

dict to boolean expression, how to? Alex van der Spek <zdoor@xs4all.nl> - 2014-08-01 12:45 +0000
  Re: dict to boolean expression, how to? Chris Angelico <rosuav@gmail.com> - 2014-08-01 23:04 +1000
  Re: dict to boolean expression, how to? Roy Smith <roy@panix.com> - 2014-08-01 09:24 -0400
  Re: dict to boolean expression, how to? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-01 13:28 +0000
    Re: dict to boolean expression, how to? Roy Smith <roy@panix.com> - 2014-08-01 09:32 -0400
      Re: dict to boolean expression, how to? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-01 15:02 +0000
        Re: dict to boolean expression, how to? Terry Reedy <tjreedy@udel.edu> - 2014-08-01 18:16 -0400
    Re: dict to boolean expression, how to? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-08-01 16:50 +0100
      Re: dict to boolean expression, how to? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-01 16:35 +0000
  Re: dict to boolean expression, how to? Alex van der Spek <zdoor@xs4all.nl> - 2014-08-01 14:26 +0000
    Re: dict to boolean expression, how to? marco.nawijn@colosso.nl - 2014-08-01 08:07 -0700
    Re: dict to boolean expression, how to? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-01 15:24 +0000
      Re: dict to boolean expression, how to? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-08-01 17:03 +0100
    Re: dict to boolean expression, how to? Peter Otten <__peter__@web.de> - 2014-08-01 17:44 +0200
      eval [was Re: dict to boolean expression, how to?] Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-02 02:59 +0000
        Re: eval [was Re: dict to boolean expression, how to?] Peter Otten <__peter__@web.de> - 2014-08-02 09:43 +0200
        Re: eval [was Re: dict to boolean expression, how to?] Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-08-02 08:59 +0100
        Re: eval [was Re: dict to boolean expression, how to?] Duncan Booth <duncan.booth@invalid.invalid> - 2014-08-05 11:57 +0000
          Re: eval [was Re: dict to boolean expression, how to?] Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-06 02:25 +1000
    Re: dict to boolean expression, how to? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-08-01 17:12 +0100
    Re: dict to boolean expression, how to? Peter Pearson <ppearson@nowhere.invalid> - 2014-08-01 17:00 +0000
  Re: dict to boolean expression, how to? Ned Batchelder <ned@nedbatchelder.com> - 2014-08-01 10:29 -0400

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