2021-09-15 Video Log - identity tracking in Python

identity_tracking_demo.py

#This is a demo for VLOG entry https://youtu.be/LfRFxkombTw "Python - track object identities [short]"

greek_alphabet = ['Άλφα', 'Βήτα', 'Γάμμα', 'Δέλτα', 'Έψιλον', 'Ζήτα', 'Ήτα', 'Θήτα', 'Ιώτα', 'Κάππα', 'Λάμβδα', 'Μυ', 'Νυ', 'Ξι', 'Όμικρον', 'Πι', 'Ρώ', 'Σίγμα', 'Ταυ', 'Ύψιλον', 'Φι', 'Χι', 'Ψι', 'Ωμέγα']


class identity_reference:
	def __init__(self, target):
		self.target = target
		self.id = id(target)
		try:
			self.hash = hash(target)
		except Exception:
			self.hash = self.id

	def __hash__(self):
		return self.hash

	def __eq__(self, other):
		if isinstance(other, identity_reference):
			return self.id == other.id
		else:
			return self.id == id(other)

	def __repr__(self):
		return f'{self.target}(ref)'

class id_representation:
	def __init__(self, sequence):
		self.sequence = iter(sequence)
		self.populated = dict()

	def __call__(self, item):
		idref = identity_reference(item)
		if existing := self.populated.get(idref):
			return existing

		new = self.sequence.__next__()
		self.populated[idref] = new
		return new


#Demo
rid = id_representation(greek_alphabet)
a, b, c = object(), object(), object()

print(rid(a), rid(b), rid(c))