Materials for Range tutorial

[gahjelle]

Where to put new files:

• New files should go into a top-level subfolder, named after the article slug. For example: my-awesome-article

How to merge your changes:

1. Make sure the CI code style tests all pass (+ run the automatic code formatter if necessary).
2. Find an RP Team member on Slack and ask them to review & approve your PR.
3. Once the PR has one positive ("approved") review, GitHub lets you merge the PR.
4. 🎉

[bzaczynski]

@gahjelle Overall, your code looks good to me. I only flagged a few minor edge cases that it would be nice to handle. Let me know what you think. Thanks!

[bzaczynski]

Should these attributes be annotated with the float | int type hint like in the FloatRange class?

Suggested change

	start: int
	stop: int
	step: int
	start: float | int
	stop: float | int
	step: float | int

[bzaczynski]

any() expects an iterable. Perhaps you're missing an extra pair of parentheses?

Suggested change

	if any(
	self.step > 0 and self.stop <= self.start,
	self.step < 0 and self.stop >= self.start,
	):
	if any((
	self.step > 0 and self.stop <= self.start,
	self.step < 0 and self.stop >= self.start,
	)):

[bzaczynski]

Same here:

Suggested change

	if any(
	self.step > 0 and element >= self.stop,
	self.step < 0 and element <= self.stop,
	):
	if any((
	self.step > 0 and element >= self.stop,
	self.step < 0 and element <= self.stop,
	)):

[bzaczynski]

This is technically float | int | None.

[bzaczynski]

The iterator protocol requires that an iterator object implements the .__iter__() method as well:

Suggested change

	def __iter__(self):
	return self

Without it, you won't be able to loop over the iterator itself or pass it into a list():

>>> for value in _FloatRangeIterator(1, 3, 0.5):
...     print(value)
...
1.0
1.5
2.0
2.5

>>> it = _FloatRangeIterator(1, 3, 0.5)
>>> list(it)
[1.0, 1.5, 2.0, 2.5]

[bzaczynski]

When .step is equal to zero, the iteration will never stop. The original range() function rejects zero as the step, so you could perhaps add similar validation in the .__post_init__() method.

[gahjelle]

I've emphasized in the docstring that _FloatRangeIterator is non-public and should only be instantiated through FloatRange which does the validation. I'll leave the foot-gun for those desperate to use it ...

[bzaczynski]

If step is zero, we should raise an error to handle edge cases:

if math.isclose(self.step, 0):
    raise ValueError("'step' must not be zero")

[gahjelle]

This is checked by if not isinstance(self.step, float | int) or self.step == 0 below. I'm switching to isclose().

[gahjelle]

Thanks @bzaczynski for the detailed review. I've updated the code.

[bzaczynski]

@gahjelle Thank you for the updates. They looks good to me 👍