On 10/09/2011 10:57 PM, Karthick Sankarachary wrote:
Hello Python Ideas,
To quote the tutorial, "List comprehensions provide a concise way to create lists without resorting to use of map(), filter() and/or lambda.".
There are a couple of constraints in the above definition that I feel could be overcome. For one thing, list comprehensions don't let you create immutable sequences (such as a tuple) by design. For another, it does not provide a concise alternative to reduce() function.
To address both of the above, I'd like to introduce tuple comprehensions, which would work like so:
freshfruit = [' banana', ' loganberry', 'passion fruit']
(weapon.strip() for weapon in freshfruit)
('banana','loganberry','passion fruit')
import operator (operator.concat(_, weapon.strip()) for weapon in freshfruit) 'bananaloganberrypassion fruit'
In addition to all previous remarks about the generator expression, what's wrong with the following?
import operator xs=['banana', 'loganberry', 'passion fruit'] reduce(operator.concat,(x.strip() for x in xs))
As you can see, we use parenthesis instead of square brackets around the comprehension.
In the first tuple comprehension, we create a true tuple with multiple items. This might a tad more efficient, not to mention less verbose, than applying the "tuple" function on top of a list comprehension.
In the second tuple comprehension, we use a reduce() function (specifically operator.concat) to concatenate all of the fruit names. In particular, we use the "_" variable (for lack of a better name) to track the running outcome of the reduce() function.
Best Regards, Karthick Sankarachary