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[QUOTE="Steven D'Aprano, post: 1849355"]
Why do you assume that everything you need for your list comprehension has
to go into a single line? Chances are your list comp already calls
functions, so just create one more for it to use.

py> def describe(cond):
....     if cond:
....         return "odd"
....     else:
....         return "even"
.... 
py> L = [describe(n % 2) for n in range(8)]
py> L
['even', 'odd', 'even', 'odd', 'even', 'odd', 'even', 'odd']

One major advantage is that this makes it easier to test your function
describe() in isolation, always a good thing.

Another advantage is that the idiom "call a function" is extensible to
more complex problems:

def describe(n):
    if n < 0:
        return "negative " + describe(-n)
    elif n == 0:
        return "zero"
    elif n % 2:
        return "odd"
    else:
        return "even"

L = [describe(n) for n in range(8)]

if much easier to understand and follow than using ternary expressions:

# obviously untested
L = ["zero" if n == 0 else \
    "negative " + ("odd" if n % 2 else "even") if n < 0 else \
    "odd" if n % 2 else "even" for n in range(8)]

Yes, I've seen ternary expressions nested three and even four deep.

I find it fascinating to read Guido's reasoning for introducing a ternary
statement. From the PEP here [URL]http://www.python.org/peps/pep-0308.html[/URL] he
links to this comment of his:
[/QUOTE]

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