rank-2-name-to-interval.py

import re

def interval_difference(interval1, interval2):
	interval_difference = (e1 - e2 for (e1, e2) in zip(interval1, interval2))
	return tuple(interval_difference)

def interval_sum(interval1, interval2):
	interval_sum = (e1 + e2 for (e1, e2) in zip(interval1, interval2))
	return tuple(interval_sum)

def quality_and_ordinal_to_interval(quality, ordinal):
	base_name_to_interval = {
		"P1": (0, 0),
		"m2": (1, 1),
		"M2": (2, 1),
		"m3": (3, 2),
		"M3": (4, 2),
		"P4": (5, 3),
		"P5": (7, 4),
		"m6": (8, 5),
		"M6": (9, 5),
		"m7": (10, 6),
		"M7": (11, 6),
	}
	name = quality + str(ordinal)
	if name in base_name_to_interval:
		return base_name_to_interval[name]
	if ordinal < 1:
		return interval_difference(quality_and_ordinal_to_interval(quality, ordinal + 7), (12, 7))
	if ordinal > 7:
		return interval_sum(quality_and_ordinal_to_interval(quality, ordinal - 7), (12, 7))
	if re.match(r"[d]+", quality):
		degree_of_diminution = len(quality)
		if ordinal in [1, 4, 5]:
			return interval_sum(quality_and_ordinal_to_interval("P", ordinal), (-degree_of_diminution, 0))
		if ordinal in [2, 3, 6, 7]:
			return interval_sum(quality_and_ordinal_to_interval("m", ordinal), (-degree_of_diminution, 0))
	if re.match(r"[A]+", quality):
		degree_of_augmentation = len(quality)
		if ordinal in [1, 4, 5]:
			return interval_sum(quality_and_ordinal_to_interval("P", ordinal), (degree_of_augmentation, 0))
		if ordinal in [2, 3, 6, 7]:
			return interval_sum(quality_and_ordinal_to_interval("M", ordinal), (degree_of_augmentation, 0))

def name_to_interval(name):
	_, quality, ordinal, _ = re.split(r"^([AdMmP]+)([0-9\-]+)$", name)
	ordinal = int(ordinal)
	interval = quality_and_ordinal_to_interval(quality, ordinal)
	return interval

print(name_to_interval("AAAAAA-8"))