A lambda function is a value. You can embed it anywhere in the middle of an expression, in nested parentheses, etc. Just try to design your own syntax for Python lambdas that allows multiple statements, ifs, fors, etc and you will quickly realize why it was done the way it is. It would require an alternative syntax for blocks that uses something other than indentation. It's not like someone has gone out of his way to discourage people from building more complex lambda functions. It was simply considered not worth the effort to invent a convoluted new syntax for it which would not be very pythonic. The alternative (write a local function and pass its name) is probably more readable, anyway, for anything longer than fits comfortably in a short lambda. It's not a value judgement – just a pragmatic choice.

The same is true for the trinary operator. Any other syntax would not be consistent with Python's syntax which is based on keywords, not magical runes. Python, unlike javascript and some other languages, does not assume the programmer necessarily has previous knowledge of C. You can understand Python's trinary operator the first time you encounter it without any explanations. It only looks strange to you because it's different from your C experience.

You can safely ignore this kind of silly opinions about discouraging the use of features. Outside of a few minor warts which are being removed in Python 3.0 everything in Python is meant to be used and enjoyed.

Python is not “holier than thou”. It simply doesn't go out of its way to provide multiple ways of doing the same thing when one is enough.

x = ( callMeIfFalse(), callMeIfTrue() )[ condition ]

both functions get called, and the value for x is chosen from the constructed tuple (since false evaluates to the 0th element of the tuple and true evaluates to the 1st). So you can't decide behavior using this method wheras you could do (in Ruby, but it's nearly identical in perl):

x = condition ? callMeIfTrue() : callMeIfFalse()

Compared to that sort of construct, X if Y else Z is much cleaner to use.

>>> True and 0 or 42
42

Also, I talk about Python's anonymous functions above… I just kind of dislike that they're hobbled. As Hans suggests, this may be a limitation of significant white space syntax – I still dislike it. :)

$is_zombie = undead() ? 'yes' : 'grr. argh.';
becomes:
is_zombie = undead() and 'yes' or 'grr. argh.'

And obviously, python does have anonymous functions as another commentor pointed out

I wasn't aware that these features are “discouraged”… first time I hear about it. I must say that Python's ternary operator is really ugly, though. I avoid it whenever possible.