__eq__メソッド は等価の条件を定める
class Person:
def __init__(self, firstname, lastname, email):
self.firstname = firstname
self.lastname = lastname
self.email = email
def __eq__(self, other):
if other is None or not isinstance(other, Person): return False
return self.firstname == other.firstname and \
self.lastname == other.lastname and \
self.email == other.email
def __ne__(self, other):
return not self.__eq__(other)
mike = Person('Mike', 'Peter', 'mike@gmail.com')
peter = Person('Mike', 'Peter', 'mike@gmail.com')
print(mike)
print(peter)
print(mike == peter)
eqの他にも、lt, ne, le, gt, geなどがある。
class Item(object):
def __init__(self, price):
self.price = price
def __eq__(self, other):
if not isinstance(other, Item):
return NotImplemented
return self.price == other.price
def __lt__(self, other):
if not isinstance(other, Item):
return NotImplemented
return self.price < other.price
def __ne__(self, other):
return not self.__eq__(other)
def __le__(self, other):
return self.__lt__(other) or self.__eq__(other)
def __gt__(self, other):
return not self.__le__(other)
def __ge__(self, other):
return not self.__lt__(other)
