4 ms·

Lots of objects don't have a natural way to return a sorted version of themselves, especially inplace (what's the reverse sort of a range, for example). You get

by aidos 4y ago

Lots of objects don't have a natural way to return a sorted version of themselves, especially inplace (what's the reverse sort of a range, for example). You get the same in Ruby, as you've just demonstrated. Sorting into a list is the only thing that makes sense in all cases. In that way `sorted` _is_ totally consistent - it always takes an iterable and returns a list of the elements. If we can't agree on that then I don't think there's much of a discussion to be had here.

peoplefromibiza 4y ago
> In that way `sorted` _is_ totally consistent - it always takes an iterable and returns a list of the elements except Iterable is the wrong "interface" in Python it is defined as > An iterable is any Python object capable of returning its members one at a time, permitting it to be iterated over in a for-loop. which is not always what you want for sorting quicksort doesn't work one element at a time so basically you have to extract all the elements before sorting them what about infinite streams? At least Ruby Enumerable mixins explicitly states that > The Enumerable mixin provides collection classes with several traversal and searching methods, and with the ability to __sort__. Another problem with sorted is that it accepts any iterable, true, returning a list of items, but it is not clear how you can tell if the object is an iterbale or not >>> sorted(123) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'int' object is not iterable ok >>> isinstance(123, iterable) Traceback (most recent call last): File "<stdin>", line 1, in <module> NameError: name 'iterable' is not defined mmmm maybe it's because int is not iterable? >>> isinstace("abc", iterable) Traceback (most recent call last): File "<stdin>", line 1, in <module> NameError: name 'iterable' is not defined so the solutions are # fails for strings in Python 2 >>> try: _ = iter(some_object) except TypeError as te: print('is not iterable') or # if 2.6 >= Python < 3.3 from collections import Iterable # if Python >= 3.3 from collections.abc import Iterable # <- personal note, abc stands for...? core maybe? # no idea on how to do it in Python < 2.6 >>> isinstance("abc", Iterable) True not only it's very ugly, but it can also fail in mysterious ways. As per documentation Checking isinstance(obj, Iterable) detects classes that are registered as Iterable or that have an __iter__() method, but it does not detect classes that iterate with the __getitem__() method. The only reliable way to determine whether an object is iterable is to call iter(obj). while in Ruby it's straightforward [3] pry(main)> [1, 2].is_a? Enumerable => true [4] pry(main)> "abc".is_a? Enumerable => false [5] pry(main)> "abc".chars.is_a? Enumerable => true

by aidos 4y ago

peoplefromibiza 4y ago

> In that way `sorted` _is_ totally consistent - it always takes an iterable and returns a list of the elements except Iterable is the wrong "interface" in Python it is defined as > An iterable is any Python object capable of returning its members one at a time, permitting it to be iterated over in a for-loop. which is not always what you want for sorting quicksort doesn't work one element at a time so basically you have to extract all the elements before sorting them what about infinite streams? At least Ruby Enumerable mixins explicitly states that > The Enumerable mixin provides collection classes with several traversal and searching methods, and with the ability to __sort__. Another problem with sorted is that it accepts any iterable, true, returning a list of items, but it is not clear how you can tell if the object is an iterbale or not >>> sorted(123) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'int' object is not iterable ok >>> isinstance(123, iterable) Traceback (most recent call last): File "<stdin>", line 1, in <module> NameError: name 'iterable' is not defined mmmm maybe it's because int is not iterable? >>> isinstace("abc", iterable) Traceback (most recent call last): File "<stdin>", line 1, in <module> NameError: name 'iterable' is not defined so the solutions are # fails for strings in Python 2 >>> try: _ = iter(some_object) except TypeError as te: print('is not iterable') or # if 2.6 >= Python < 3.3 from collections import Iterable # if Python >= 3.3 from collections.abc import Iterable # <- personal note, abc stands for...? core maybe? # no idea on how to do it in Python < 2.6 >>> isinstance("abc", Iterable) True not only it's very ugly, but it can also fail in mysterious ways. As per documentation Checking isinstance(obj, Iterable) detects classes that are registered as Iterable or that have an __iter__() method, but it does not detect classes that iterate with the __getitem__() method. The only reliable way to determine whether an object is iterable is to call iter(obj). while in Ruby it's straightforward [3] pry(main)> [1, 2].is_a? Enumerable => true [4] pry(main)> "abc".is_a? Enumerable => false [5] pry(main)> "abc".chars.is_a? Enumerable => true