Teaching Programming

[Benjamin Kaplan]

On Tue, May 4, 2010 at 2:16 PM, superpollo <utente at esempio.net> wrote:
> superpollo ha scritto:
>>
>> James Mills ha scritto:
>>>
>>> On Tue, May 4, 2010 at 9:56 PM, superpollo <utente at esempio.net> wrote:
>>>>
>>>> of course! *but* if i must generate on-the-fly python code that defines
>>>> a
>>>> function i am back again to the problem:
>>>
>>> One-liner:
>>>
>>> $ python
>>> Python 2.6.5 (r265:79063, Apr 27 2010, 18:26:49)
>>> [GCC 4.4.1 (CRUX)] on linux2
>>> Type "help", "copyright", "credits" or "license" for more information.
>>>>>>
>>>>>> a, b = 2, 3
>>>>>> print a + b if a > b else a**b - b**2
>>>
>>> -1
>>>>>>
>>>>>> a, b = 3, 2
>>>>>> print a + b if a > b else a**b - b**2
>>>
>>> 5
>>>
>>> --James
>>
>> what if i want an elif clause?
>>
>
> my first try obviously falied:
>
>>>> print a + b if a > b elif a=b "WOW" else a**b - b**2
>  File "<stdin>", line 1
>    print a + b if a > b elif a=b "WOW" else a**b - b**2
>                            ^
> SyntaxError: invalid syntax

That's because this technically isn't an if statement. It's the
ternary conditional expression. If you want multiple conditions, you
have to repeat the expression

print a+b if a > b else "WOW" if a==b else a**b - b**2


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