custom_iterator_object

custom_iterator_object.py

class CustomIterTeams(object):
	def __init__(self, division, teams=[]):
		self._mng = division
		self._teams = teams
		self._index = -1

	def __iter__(self):
		return self

# 	def __iter__(self):
# 		return (t for t in self._teams)

	def __next__(self):
		self._index += 1
		if self._index >= len(self._teams):
			self._index = -1
			raise StopIteration
		else:
			return self._teams[self._index]

	def __reversed__(self):
		return self._teams[::-1]


prem_teams = CustomIterTeams('Premier League', ['Arsenal', 'Watford', 'Bournemouth', 'Man Utd', 'Liverpool'])

for t in prem_teams:
	print(t)

This is a buggy implementation.

Try doing this :

prem_teams = CustomIterTeams('Premier League', ['Arsenal', 'Watford', 'Bournemouth' ])
for t in prem_teams:
	break

# ===== PRINT STARTS FROM `Watford` and NOT `Arsenal` ===== #
for t in prem_teams:
	print(t)

SOLUTION :
This is the correct way to ensure that iterable object can be used multiple times.
https://stackoverflow.com/questions/21665485/how-to-make-a-custom-object-iterable

class BarIterator(object):
    def __init__(self, data_sequence):
        self.idx = 0
        self.data = data_sequence
    def __iter__(self):
        return self
    def __next__(self):
        self.idx += 1
        try:
            return self.data[self.idx-1]
        except IndexError:
            self.idx = 0
            raise StopIteration  # Done iterating.


class Bar(object):
    def __init__(self, data_sequence):
        self.data_sequence = data_sequence
    def __iter__(self):
        return BarIterator(self.data_sequence)