On Jan 20, 10:34 pm, "Barak, Ron" <ron.ba...@lsi.com> wrote: > What I still don't understand is why the print does not > execute the lambda and prints the result, instead of > printing the lambda's object description.
The following two statements are identical: >>> def f(x): return x ... >>> f = lambda x: x lambda _creates_ a function, it's up to you to actually _call_ the function. Functions are first class objects in Python, so the tuple you're passing in to the string format contains a number and a function. Tino's solutions are definitely more what you're looking for, but for your lambda version to work, you have to actually call the lambda function, passing in num when you do so (as you've specified that the lambda function requires one argument): >>> for num in range(1, 4): ... string_ = "%d event%s" % (num, (lambda num: num > 1 and "s" or "")(num)) ... print string_ Or you can remove the argument and create a closure using the num value from the loop: ... string_ = "%d event%s" % (num, (lambda: num > 1 and "s" or "") ()) But again, this is generally overkill when all you're after is a conditional value. Personally, I tend to use lambdas for passing small units of functionality into other functions, or if I want to create a quick closure. Your mileage may vary on what you consider a suitable use case, but you will -still- have to call your lambda in order for it to execute :) Generally -- http://mail.python.org/mailman/listinfo/python-list
