1. Creating your own classes class Elephant(object): """A virtual pet""" def __init__(self, name, age, weight, trunkradius, trunklength): self.name = name self.age = age self.weight = weight self.trunkradius = trunkradius self.trunklength = trunklength We now have a class of Elephants Elephants starts with a capital letter Our Elephants all have names and ages. __init__: __init__() is always the constructor in Python The two __ on both sides of the word init indicate that it is a special name Constructor is automatically invoked when the an object of this type is created.

2. Creating an Elephant named Rita: class Elephant(object): """A virtual pet""“ def __init__(self, name, age, weight, trunkradius, trunklength): self.name = name self.age = age self.weight = weight self.trunkradius = trunkradius self.trunklength = trunklength # main elephant1 = Elephant(“Rita”,32,6080,10,96) print(“The Elephant’s name is “ + elephant1.name + “and her age is “ + str(elephant1.age)) elephant2 = Elephant(“Harold”,28,7940,14,100) print(“The Elephant’s name is “ + elephant2.name + “and his age is “ + str(elephant2.age))

3. Creating an Elephant named Rita: class Elephant(object): """A virtual pet""“ def __init__(self, name, age, weight, trunkradius, trunklength): self.name = name self.age = age self.weight = weight self.trunkradius = trunkradius self.trunklength = trunklength # main elephant1 = Elephant(“Rita”,32,6080,10,96) print(“The Elephant’s name is “ + elephant1.name + “and her age is “ + elephant1.age) print(“Her trunk’s volume is" ) ???

4. Creating an Elephant named Rita: class Elephant(object): """A virtual pet""" def __init__(self, name, age, weight, trunkradius, trunklength): self.name = name self.age = age self.weight = weight self.trunkradius = trunkradius self.trunklength = trunklength def trunkvol(self): return(self.trunkradius**2 * math.pi * self.trunklength) # main elephant1 = Elephant("Rita",32,6080,10,96) print("The Elephant's name is " + elephant1.name + "and her age is " + str(elephant1.age)) print("Her trunk's volume is " + str(elephant1.trunkvol() ))

5. Example: class Rectangle(object): """ A rectangle is a shape with width and height [DESCRIPTION] width - number [PROPERTIES] height - number """ def __init__(self, width, height): #[CONSTRUCTOR] self.width = width self.height = height """ def Rect_function(self,...): [TEMPLATE] return self.width... self.height... ""“ #main rectangle1 = Rectangle(10, 10) #[EXAMPLES] rectangle2 = Rectangle(20, 5)

6. from cisc106 import * class Rectangle: """ A rectangle is a shape with width and height [DESCRIPTION] width - number [PROPERTIES] height - number """ def __init__(self, width, height): #[CONSTRUCTOR] self.width = width self.height = height """ def Rect_function(self,...): [TEMPLATE] return self.width... self.height... """ def area(self): """ Computes the area of a Rectangle object aRectangle - Rectangle return - number """ return self.width * self.height rectangle1 = Rectangle(10, 10) #[EXAMPLES] rectangle2 = Rectangle(20, 5) assertEqual(rectangle1.area(), 100) assertEqual(rectangle2.area(), 100) assertEqual(Rectangle(6,8).area(),48)

7. from cisc106 import * class Rectangle: def __init__(self, width, height): #[CONSTRUCTOR] self.width = width self.height = height def area(self): return self.width * self.height def boxvol(self,x): return self.width * self.height * x mugwump = Rectangle(10, 10) #[EXAMPLES] rectangle2 = Rectangle(20, 5) assertEqual(mugwump.area(), 100) assertEqual(rectangle2.boxvol(2), 200) assertEqual(Rectangle(6,8).area(),48)

8. Class for a wallet? class Wallet(object): def __init__(self,tw,te,fi,on,ch): self.twenties = tw self.tens = te self.fives = fi self.ones = on self.change = ch self.amount = self.calcamt() def calamt(self): return self.twenties*20 + self.tens * 10 + self.fives * 5 + self.ones + self.change/100.0 def spend(self,spend_amt): if spend_amt >= 20: self.twenties = self.twenties - math.floor(spend_amt/20) spend_amt = spend_amt%20 if spend_amt >= 10: self.tens = self.tens - math.floor(spend_amt/10) spend_amt = spend_amt%10 if spend_amt >= 5: self.fives = self.fives - math.floor(spend_amt/5) spend_amt = spend_amt%5 if spend_amt >= 1: self.ones = self.ones - math.floor(spend_amt) spend_amt = spend_amt%1 self.change = self.change - spend_amt * 100 self.amount = self.calcamt() wallet = Wallet(2,3,5,3,24) assertEqual(wallet.amount,98.24) wallet.spend(22.12) assertEqual(wallet.amount, _________) assertEqual(wallet.amount, 76.12) wallet.spend(35.25) assertEqual(wallet.amount,_________) assertEqual(wallet.amount,40.87) Now write a method (class function) to add money to the wallet (Much simpler function!)

9. class Wallet: def __init__(self,tw,te,fi,on,ch): self.twenties = tw self.tens = te self.fives = fi self.ones = on self.change = ch self.amount = self.calc_amt() def calc_amt(self): return self.twenties*20 + self.tens * 10 + self.fives * 5 + self.ones + self.change/100.0 def add(self,tw,te,fi,on,ch): self.twenties += tw self.tens = self.tens + te self.fives = self.fives + fi self.ones = self.ones + on self.change = self.change + ch self.amount = self.calc_amt() def spend(self,spend_amt): if spend_amt >= 20: self.twenties = self.twenties - math.floor(spend_amt/20) spend_amt = spend_amt%20 if spend_amt >= 10: self.tens = self.tens - math.floor(spend_amt/10) spend_amt = spend_amt%10 if spend_amt >= 5: self.fives = self.fives - math.floor(spend_amt/5) spend_amt = spend_amt%5 if spend_amt >= 1: self.ones = self.ones - math.floor(spend_amt) spend_amt = spend_amt%1 self.change = self.change - spend_amt * 100 self.amount = self.calc_amt() wally = Wallet(3,2,2,4,1,32) wally.add(1,1,1,1,1)

10. from datetime import * class StopWatch(object): def __init__(self): now = datetime.now() self.hr = now.hour self.min = now.minute self.sec = now.second self.micro = now.microsecond def converttoms(self): return self.micro+self.sec*1000000+self.min*60*1000000+self.hr*60*60*1000000 def time_diff(self,watch): x = self.converttoms() y = watch.converttoms() diff = abs(x - y) return(diff) time1 = StopWatch() print time1.micro time2 = StopWatch() print time2.micro print(time1.time_diff(time2)) Class Stopwatch?