doubt.py

class JustAnotherClass(object):

    _sentinel = object()

    def __init__(self, value):
        self.value = value

    def consume1(self):
        try:
            return self.value
        finally:
            self.value = self._sentinel

    def consume2(self):
        _value = self.value
        self.value = self._sentinel
        return _value