[barrkel]

By who?

I always have to stare at list comprehensions very closely to understand operation being done. The source of the data is in the middle, where it should logically come first. The filter is at the end, where logically it should come after the source. The mapping is at the start, where logically it should come at the end.

I find the monadic, additive style of Ruby much easier to understand:

    10.times.select { |x| x != 5 }.map { |x| x ** 2 }

IMO it's more composable. What if you want to exclude even numbers from the result? Just add another filter:

    10.times.select { |x| x != 5 }.map { |x| x ** 2 }.select { |x| x % 2 != 0 }

Incrementally building up a streaming computation this way is much more useful to me than a list comprehension.

For example, you can add a lazy to the stream to avoid performing all the operations eagerly, and now you have a way to process sequences without blowing out your memory.

[samwillis]

> By who?

By the Python developers and its wider community. As Python doesn't have anonymous function blocks in the same way as Ruby (only lambda expressions), tutorials, lessons and the Python docs steer users toward list comprehensions instead.

I'm not saying the ruby syntax is not elegant (it is), I'm saying in Python list comprehensions are recommended over filter/map functions.

On the composable front, personally I prefer to breaks these down into smaller chunks with descriptive variable names rather than chaining.

Python also has the sister "generator" (() rather than []) syntax which also ensures it remains efficient as it pipelines the whole sequence of generators. (Lazily rather than eagerly as you say)

[DwnVoteHoneyPot]

You're effectively saying something like: Canadians prefer Canada. What about the rest of the world?

Once you start adding more "and" to the if-statement in the list comprehension, it becomes a mess. Breaking them down to smaller chunks is required because comprehensions are messy. You are doing smaller chunks due to a shortcoming of comprehensions. Chaining is nice option to have, especially when the chained functions are straight forward.

[lcnPylGDnU4H9OF]

> Map/filter are considered inferior in Python to list comprehensions.

> By who?

> By the Python developers and its wider community.

> You're effectively saying something like: Canadians prefer Canada. What about the rest of the world?

They're actually saying that Python developers prefer one particular way of doing something rather than a different particular way of doing the same thing. You're suggesting that they're saying Python developers (Canadians) prefer Python (Canada).

I don't mean to speak against your broader points, just that this specific call out is mistaken.