Records contain a number of attributes.<\/p>\n
An object<\/strong> contains attributes<\/strong>, and functions (called methods<\/strong>) to get or set these attributes.<\/p>\n Computer has a fixed ID and type. It has an operating system that can be updated. Records contain a number of attributes. An object contains attributes, and functions (called methods) to get or set these attributes. UML Diagram for Example Computer has a fixed ID and type. It has an operating system that can be updated. Phone is a subclass type of computer, with an additional attribute and methods. Computer <—– Phone ———- ———- – id : string; – operator : string; – type : string;<\/p>\nUML Diagram for Example<\/h1>\n
\nPhone is a subclass type of computer, with an additional attribute and methods.<\/p>\nComputer <----- Phone\n---------- ----------\n- id : string; - operator : string;\n- type : string; ----------\n- os: string; + getOperator()\n---------- + changeOperator()\n+ getID()\n+ getType()\n+ getOS()\n+ updateOS()<\/pre>\n
\r\n#define a new class\r\nclass Computer():\r\n # constructor method with parameters\r\n def __init__(self, id, type, os):\r\n #assign parameter values to object attributes\r\n self.id = id\r\n self.type = type\r\n self.os = os\r\n \r\n #initial attributes can be manipulated\r\n self.id = self.id.upper()\r\n\r\n # some attributes have default values\r\n self.previousOS = []\r\n \r\n #str method provides formatted output for print commands\r\n def __str__(self):\r\n str = f"ID: {self.id:15} "\r\n str += f"Type: {self.type:10} "\r\n str += f"OS: {self.os}"\r\n str += f"\\nPrevious OS: {self.previousOS}"\r\n return str\r\n \r\n # methods to get values of attributes (getters)\r\n def getID(self):\r\n return self.id\r\n \r\n def getType(self):\r\n return self.type\r\n \r\n def getOS(self):\r\n return self.os\r\n \r\n def getPreviousOS(self):\r\n return self.previousOS\r\n \r\n # methods to update attributes (setters)\r\n def updateOS(self, newOS):\r\n self.previousOS.append(self.os)\r\n self.os = newOS\r\n \r\n# MAIN PROGRAM \r\n# instantiation of an object of the class \r\ncomputer1 = Computer("AHS1913013","Desktop","Windows Vista")\r\nprint(computer1)\r\n\r\n#use a setter method\r\ncomputer1.updateOS("Windows 10 Professional")\r\nprint(computer1)\r\n\r\n#use getter methods\r\nid = computer1.getID()\r\ntype = computer1.getType()\r\nprint(f"Computer {id} is {type}")\r\n<\/pre>\nID: AHS1913013 Type: Desktop OS: Windows Vista\nPrevious OS: []\n \nID: AHS1913013 Type: Desktop OS: Windows 10 Professional\nPrevious OS: ['Windows Vista']\n \nComputer AHS1913013 is Desktop\n<\/pre>\n
\r\n# new class Phone is a subclass of Computer\r\nclass Phone(Computer):\r\n # polymorphism 1\r\n def __init__(self, id, os, operator):\r\n # call superclass contructor\r\n super().__init__(id, "Phone", os)\r\n # add subclass specific attributes\r\n self.operator = operator\r\n \r\n # polymorphism 2\r\n # used instead of superclass' method\r\n def __str__(self):\r\n str = f"ID: {self.id:15} "\r\n str += f"Type: {self.type:10} "\r\n str += f"OS: {self.os:10} "\r\n str += f"Operator: {self.operator}"\r\n str += f"\\nPrevious OS: {self.previousOS}"\r\n return str\r\n \r\n def getOperator(self):\r\n return self.operator\r\n \r\n def changeOperator(self, newOperator):\r\n self.operator = newOperator\r\n\r\n# MAIN PROGRAM\r\ncomputer1 = Computer("AHS1913013","Desktop","Windows Vista")\r\nprint(computer1)\r\n \r\nphone1 = Phone("XYZ1234567","Android 8","EE")\r\nprint(phone1)\r\n<\/pre>\nID: AHS1913013 Type: Desktop OS: Windows Vista\nPrevious OS: []\n \nID: XYZ1234567 Type: Phone OS: Android 8 Operator: EE\nPrevious OS: []\n<\/pre>\n","protected":false},"excerpt":{"rendered":"