Using built-in slice for indexing

At one place I consult I saw something like the following code:

	def fn1(items, use_tail=False):
	if use_tail:
	key = items[-2:]
	else:
	key = items[0]
	print(key)
	items = [1, 2, 3, 4, 5]
	fn1(items)
	fn1(items, True)

view raw slice-1.py hosted with ❤ by GitHub

This is good and valid Python code, however we can use the slice built-in slice to do the same job.

	def fn2(items, use_tail=False):
	idx = slice(-2, None) if use_tail else 0
	key = items[idx]
	print(key)
	items = [1, 2, 3, 4, 5]
	fn2(items)
	fn2(items, True)

view raw slice-2.py hosted with ❤ by GitHub

Also when you're writing your own __getitem__ consider that key might be a slice object.

Weighted Rating

Notebook here.