the PHP ternary operator equivalent on Python

[Daniel Crespo]

Hi!

I would like to know how can I do the PHP ternary operator/statement
(... ? ... : ...) in Python...

I want to something like:

a = {'Huge': (quantity>90) ? True : False}

Any suggestions?

Thanks

Daniel

[Simon Brunning]

On 18 Nov 2005 10:53:04 -0800, Daniel Crespo <dc*****@gmail. com> wrote:

I would like to know how can I do the PHP ternary operator/statement
(... ? ... : ...) in Python...

Wait for Python 2.5 - <http://www.python.org/peps/pep-0308.html>.

--
Cheers,
Simon B,
si***@brunningo nline.net,
http://www.brunningonline.net/simon/blog/

[Simon Brunning]

On 18 Nov 2005 10:53:04 -0800, Daniel Crespo <dc*****@gmail. com> wrote:

I would like to know how can I do the PHP ternary operator/statement
(... ? ... : ...) in Python...

Wait for Python 2.5 - <http://www.python.org/peps/pep-0308.html>.

--
Cheers,
Simon B,
si***@brunningo nline.net,
http://www.brunningonline.net/simon/blog/

[David Wahler]

Daniel Crespo wrote:

I would like to know how can I do the PHP ternary operator/statement
(... ? ... : ...) in Python...

I want to something like:

a = {'Huge': (quantity>90) ? True : False}

Well, in your example the '>' operator already returns a boolean value
so you can just use it directly. Hoewver, I agree that there are
situations in which a ternary operator would be nice. Unfortunately,
Python doesn't support this directly; the closest approximation I've
found is:

(value_if_false , value_if_true)[boolean_value]
This exploits the fact that False and True are converted to integers as
zero and one, respectively. The downside is that it's really ugly.
Also, it doesn't use minimal evaluation; in other words, if you try an
expression like:
(None, func())[callable(func)]
You might think this would return the value of func() if it's callable,
and None otherwise. Unfortunately, func() is evaluated no matter what,
even if the condition is false.

Of course, you can always get around this by doing really cryptic stuff
with lambdas:
(lambda: None, lambda: func())[callable(func)]()

.... but by that point, you're better off just using an if/then/else.

-- David

[David Wahler]

Daniel Crespo wrote:

I would like to know how can I do the PHP ternary operator/statement
(... ? ... : ...) in Python...

I want to something like:

a = {'Huge': (quantity>90) ? True : False}

Well, in your example the '>' operator already returns a boolean value
so you can just use it directly. Hoewver, I agree that there are
situations in which a ternary operator would be nice. Unfortunately,
Python doesn't support this directly; the closest approximation I've
found is:

(value_if_false , value_if_true)[boolean_value]
This exploits the fact that False and True are converted to integers as
zero and one, respectively. The downside is that it's really ugly.
Also, it doesn't use minimal evaluation; in other words, if you try an
expression like:
(None, func())[callable(func)]
You might think this would return the value of func() if it's callable,
and None otherwise. Unfortunately, func() is evaluated no matter what,
even if the condition is false.

Of course, you can always get around this by doing really cryptic stuff
with lambdas:
(lambda: None, lambda: func())[callable(func)]()

.... but by that point, you're better off just using an if/then/else.

-- David

[Mike Meyer]

"Daniel Crespo" <dc*****@gmail. com> writes:

Hi!

I would like to know how can I do the PHP ternary operator/statement
(... ? ... : ...) in Python...

I want to something like:

a = {'Huge': (quantity>90) ? True : False}

Any suggestions?

Lots of ways, depending on your exact needs. What's best for what you
suggest is "a = {Huge : (False, True)[quantity > 90]}". Googling the
python newsgroup will turn up lots of others.

<mike
--
Mike Meyer <mw*@mired.or g> http://www.mired.org/home/mwm/
Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information.

[Mike Meyer]

"Daniel Crespo" <dc*****@gmail. com> writes:

Hi!

I would like to know how can I do the PHP ternary operator/statement
(... ? ... : ...) in Python...

I want to something like:

a = {'Huge': (quantity>90) ? True : False}

Any suggestions?

Lots of ways, depending on your exact needs. What's best for what you
suggest is "a = {Huge : (False, True)[quantity > 90]}". Googling the
python newsgroup will turn up lots of others.

<mike
--
Mike Meyer <mw*@mired.or g> http://www.mired.org/home/mwm/
Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information.

[gene tani]

Mike Meyer wrote:

"Daniel Crespo" <dc*****@gmail. com> writes:

Hi!

I would like to know how can I do the PHP ternary operator/statement
(... ? ... : ...) in Python...

I want to something like:

a = {'Huge': (quantity>90) ? True : False}

Any suggestions?

Lots of ways, depending on your exact needs. What's best for what you
suggest is "a = {Huge : (False, True)[quantity > 90]}". Googling the

http://www.python.org/doc/faq/progra...rnary-operator

[gene tani]

Mike Meyer wrote:

"Daniel Crespo" <dc*****@gmail. com> writes:

Hi!

I would like to know how can I do the PHP ternary operator/statement
(... ? ... : ...) in Python...

I want to something like:

a = {'Huge': (quantity>90) ? True : False}

Any suggestions?

Lots of ways, depending on your exact needs. What's best for what you
suggest is "a = {Huge : (False, True)[quantity > 90]}". Googling the

http://www.python.org/doc/faq/progra...rnary-operator

[Daniel Crespo]

Oh... Well, thanks for that information.

I'll do this then:

def TernaryOperatio n(condition,tru e_part,false_pa rt):
if condition:
return True-part
else:
return False-part

a = {'Huge': TernaryOperatio n(quantity>90,T rue,False)}

Thank you