Object Oriented Programming Part 2¶
Example 1 Building class inheritence¶
class loan:
#parent class
def statement(self):
print('I am a bank loan')
class mortgage(loan):
#child class
def announcement(self):
print('My interest rate')
m = mortgage()
m.announcement()
m.statement()
Example 2: Parent-child classes¶
Parent-child classes that have methods of the same name.
class animal:
def statement(self):
print('animal class')
class fish(animal):
def statement(self):
print('fish class')
f = fish()
f.statement()
Example 3: Overriding the child classes' method¶
Overriding the child classes' method that shares the same name as the parent via the super() clause
class animal:
def statement(self):
return 'animal class'
class fish(animal):
def statement(self):
if super().statement() is not None:
return super().statement()
else:
return 'fish class'
f = fish()
f.statement()
Example 4: Using the super() method¶
class to extract the constructor from the parent class into the child class
class loan:
def __init__(self,rate):
self.rate=rate
def statement(self):
return 'the rate is {}%'.format(self.rate)
class mortgage(loan):
def __init__(self,rate,downpayment):
super().__init__(rate)
self.downpayment = downpayment
def statement(self):
return super().statement()+' and downpayment is {}'.format(self.downpayment)
l = loan(3)
m = mortgage(l.rate,10000)
m.statement()
Example 5: Definine name spaces/variable scopes¶
#global name space
def outer_function():
#enclosed name space
n=100
def inner_function():
#local name space
m=200
Example 6: Demonstrating local name spaces¶
Example 7: Demonstrating global name spaces¶
Example 8: Polymorphisms¶
A basic polymorphism in python
dictionary = {'a':10,'b':20,'c':30,'d':40}
word = 'alpha'
List = [0,1,2,3]
print(len(dictionary))
print(len(word))
print(len(List))
Example 9: Demonstrating using a polymorphism¶
Demonstrating using a polymorphism for classes that have attributes of the same name (with a list)
class animal:
def __init__(self,name):
self.name = name
class plant:
def __init__(self,name):
self.name = name
for c in [animal('dolphin'),plant('birch_tree')]:
print(c.name)
Example 10: Polymorphisms the share names¶
Demonstrating using a polymorphism for classes that have attributes of the same name (with a function)
class animal:
def __init__(self,name):
self.name = name
class plant:
def __init__(self,name):
self.name = name
def class_polymorphism_printer(c):
print(c.name)
class_polymorphism_printer(plant('venus_fly_trap'))
class_polymorphism_printer(animal('cow'))
Example 11: Class polymorphism with inheritence¶
using the parent-child inheritence to alter the methods of the child class.