Addons: refactor flyout sorting

[humitos]

sort_versions_python_packaging and sort_versions_custom_pattern functions share most of their code. The only part that differs is what's inside try/catch. Here is the code involved:

readthedocs.org/readthedocs/projects/version_handling.py

Lines 226 to 272 in f0c74a6

	def sort_versions_custom_pattern(version_list, raw_pattern, latest_stable_at_beginning):
	"""
	Sort Read the Docs versions using a custom pattern.
	All the invalid version (raise ``PatternError``) are added at the end
	sorted alphabetically.
	It uses ``Bumpver`` behinds the scenes for the parsing and sorting.
	https://github.com/mbarkhau/bumpver
	"""
	alphabetically_sorted_version_list = sorted(
	version_list,
	key=operator.attrgetter("slug"),
	)
	initial_versions = []
	valid_versions = []
	invalid_versions = []
	for i, version in enumerate(alphabetically_sorted_version_list):
	if latest_stable_at_beginning:
	if version.slug in (STABLE, LATEST):
	# It relies on the version list sorted alphabetically first ("l" comes first than "s")
	initial_versions.append((version, version.slug))
	continue
	try:
	valid_versions.append(
	(
	version,
	parse_version_info(
	version.slug,
	raw_pattern=raw_pattern,
	),
	)
	)
	except PatternError:
	# When the version is invalid, we put it at the end while keeping
	# the alphabetically sorting between the invalid ones.
	invalid_versions.append((version, None))
	all_versions = (
	initial_versions
	+ sorted(valid_versions, key=operator.itemgetter(1), reverse=True)
	+ invalid_versions
	)
	return [item[0] for item in all_versions if item[0] is not None]

Reference #11069 (comment)

[humitos]

I jumped into this issue and I'm still not sure what's the best way to refactor this code. Basically, the only part we need to change is the try/except clause. All the rest is identical.

On that try/except clause the different parts are:

• the exception that needs to be handled
• the second argument required to generate the tuple

Would it be enough to isolate all this code in a function that receives exception= and parse_version=? 🤔

[humitos]

I implemented this idea in #11278