Multiple conditional expression

[Anjanesh Lekshminarayanan]

How do I achieve something like this using python ?
spaces = (form.has_key('spaces') ? form.getvalue('spaces') == 1 ? True
: False : False)

spaces = True if form.getvalue('spaces') == 1 if
form.has_key('spaces') else False else False
--
Anjanesh Lekshmnarayanan

[Steve Holden]

Anjanesh Lekshminarayanan wrote:
> How do I achieve something like this using python ?
> spaces = (form.has_key('spaces') ? form.getvalue('spaces') == 1 ? True
> : False : False)
>
> spaces = True if form.getvalue('spaces') == 1 if
> form.has_key('spaces') else False else False

If you've got any sense at all, you don't. Write the logic so it makes
some sense to the casual reader. You will be that casual reader in a few
months.

regards
Steve
--
Steve Holden +1 571 484 6266 +1 800 494 3119
Holden Web LLC http://www.holdenweb.com/

[Chris Rebert]

On Thu, Feb 26, 2009 at 7:11 PM, Anjanesh Lekshminarayanan
<ma...@anjanesh.net> wrote:
> How do I achieve something like this using python ?
> spaces = (form.has_key('spaces') ? form.getvalue('spaces') == 1 ? True
> : False : False)
>
> spaces = True if form.getvalue('spaces') == 1 if
> form.has_key('spaces') else False else False

That seems to just be an overly complicated way of writing:

spaces = bool(form.has_key('spaces') and form.getvalue('spaces') == 1)

Cheers,
Chris

--
Follow the path of the Iguana...
http://rebertia.com

[Grant Edwards]

On 2009-02-27, Anjanesh Lekshminarayanan <ma...@anjanesh.net> wrote:

> How do I achieve something like this using python ?
> spaces = (form.has_key('spaces') ? form.getvalue('spaces') == 1 ? True : False : False)

if form.has_key('spaces'):
spaces = form.getvalue('spaces') == 1
else:
spaces = False

However, my code is not acheiving entirely the same thing as
your example code. The object 'spaces' ends up with the same
value, but my code fails to acheive the other presumed
objective: confusing the reader.

--
Grant

[Paul Rubin]

Chris Rebert <cl...@rebertia.com> writes:
> spaces = bool(form.has_key('spaces') and form.getvalue('spaces') == 1)

spaces = form.has_key('spaces') and form.getvalue('spaces') == 1

or even (this is about the cgi module, I think)

spaces = form.getvalue('spaces', None) == 1

But the == 1 comparison will always fail, since getvalue returns a string.

[Grant Edwards]

On 2009-02-27, Paul Rubin <http> wrote:

> But the == 1 comparison will always fail, since getvalue returns a string.

How do we know that from the what the OP posted?

--
Grant

[Anjanesh Lekshminarayanan]

> How do we know that from the what the OP posted?

Its CGI alright.
spaces = form.has_key('spaces') and form.getvalue('spaces') == '1'

But I just dont see how
spaces = (form.has_key('spaces') ? form.getvalue('spaces') == 1 ?
True: False : False)
is complicated in anyway. Its not that hard to read at all.

Thanks.

[Chris Rebert]

On Thu, Feb 26, 2009 at 8:39 PM, Anjanesh Lekshminarayanan
<ma...@anjanesh.net> wrote:
>> How do we know that from the what the OP posted?

> Its CGI alright.
> spaces = form.has_key('spaces') and form.getvalue('spaces') == '1'
>
> But I just dont see how
> spaces = (form.has_key('spaces') ? form.getvalue('spaces') == 1 ?
> True: False : False)
> is complicated in anyway. Its not that hard to read at all.

You have /nested/ /ternary/ expressions /without/ any disambiguating
parentheses. And you unnecessarily use boolean constants. The latter
and the stuff in italics is what makes your code hard to understand.

As I showed, you can write the *exact same thing* without using
ternary expressions at all (win!), much less nested ones, and without
any boolean constants.
And it's even 16 characters shorter.

[bearoph...@lycos.com]

Chris Rebert:

> That seems to just be an overly complicated way of writing:
>
> spaces = bool(form.has_key('spaces') and form.getvalue('spaces') == 1)

Better:

spaces = bool(('spaces' in form) and form.getvalue('spaces') == 1)

Bye,
bearophile

[Steve Holden]

Anjanesh Lekshminarayanan wrote:
>> How do we know that from the what the OP posted?

> Its CGI alright.
> spaces = form.has_key('spaces') and form.getvalue('spaces') == '1'
>
> But I just dont see how
> spaces = (form.has_key('spaces') ? form.getvalue('spaces') == 1 ?
> True: False : False)
> is complicated in anyway. Its not that hard to read at all.
>

In that case I fear Python will be far too simple for your clearly
impressive mind. You've been programming for way too long ...

[Bruno Desthuilliers]

Steve Holden a écrit :

> Anjanesh Lekshminarayanan wrote:
>>> How do we know that from the what the OP posted?
>> Its CGI alright.
>> spaces = form.has_key('spaces') and form.getvalue('spaces') == '1'
>>
>> But I just dont see how
>> spaces = (form.has_key('spaces') ? form.getvalue('spaces') == 1 ?
>> True: False : False)
>> is complicated in anyway. Its not that hard to read at all.
>>
> In that case I fear Python will be far too simple for your clearly
> impressive mind. You've been programming for way too long ...

+1 QOTW !-)

[Christian Tismer]

Bruhahaa, my biggest laugh since months

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[John Machin]

Huh?? Much better is:
spaces = 'spaces' in form and form.getvalue('spaces') == 1

Then you go looking at "form": form.getvalue behaves just like
dict.get, and returns a non-None object (a str object). So the guard
clause can be retired; the ingloriously superobfuscatory original can
be compressed LEGIBLY into
spaces = form.getvalue('spaces') == "1"

[Mel]

Is it still necessary to convert the result (and of two comparison
operations) to bool?

Mel.

[John Machin]

On Mar 4, 10:53 am, Mel <mwil...@the-wire.com> wrote:

Still? It never was necessary.