{
"metadata": {
"name": "",
"signature": "sha256:dbbd8ed92141bcc804ff2fbeacf8bb85f122dc6e196e1d830291a4a449a3a439"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 8: Data Abstraction through Classes and User-Defined Data Types "
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Program Source Code 8.1, page no: 208"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"class Super:\n",
" def __init__(self):\n",
" self.__IntegerData=None #private member\n",
" #public functions\n",
" def SetData(self,i):\n",
" self.__IntegerData=i #refer to IntegerData\n",
" def ShowData(self):\n",
" print \"Data is \",self.__IntegerData,' '\n",
"\n",
"ob1=Super()\n",
"ob2=Super()\n",
"ob1.SetData(1000)\n",
"ob2.SetData(2000)\n",
"ob1.ShowData()\n",
"ob2.ShowData()"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Data is 1000 \n",
"Data is 2000 \n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Program Source Code 8.2, page no:211"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"class X:\n",
" def __init__(self):\n",
" self.a=None #private members\n",
" self.b=None #private members\n",
" \n",
"#no structure type present in python \n",
"x = X()\n",
"\n",
"x.a=0\n",
"x.b=1\n",
"print \"x.a=\",x.a,\",x.b=\",x.b"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"x.a= 0 ,x.b= 1\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Program Source Code 8.3, page no:214"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"class Fraction:\n",
" \n",
" def SetValue(self,a,b): #public functions\n",
" self.__num=a \n",
" self.__denom=b \n",
" def GetValue(self,a,b):\n",
" a=self.__num\n",
" b=self.__denom\n",
" \n",
"f=Fraction()\n",
"n=input(\"Enter n: \") #user input\n",
"d=input(\"Enter d: \") #user input\n",
"print \"enter the numerator and denominator: \", ' ',n,d\n",
"\n",
"f.SetValue(n,d) #call function SetValue\n",
"print \"Numerator value set: \", ' ',n\n",
"print \"Denominator value set: \", ' ',d\n",
"f.GetValue(n,d) #call function GetData\n",
"print \"Numerator value retrieved: \", ' ',n\n",
"print \"Denominator value retrieved: \", ' ',d"
],
"language": "python",
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"stream": "stdout",
"text": [
"Enter n: 3\n"
]
},
{
"name": "stdout",
"output_type": "stream",
"stream": "stdout",
"text": [
"Enter d: 4\n"
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"enter the numerator and denominator: 3 4\n",
"Numerator value set: 3\n",
"Denominator value set: 4\n",
"Numerator value retrieved: 3\n",
"Denominator value retrieved: 4\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Program Source Code 8.4, page no:216"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"class SimpleClass:\n",
" def __init__(self):\n",
" self.__i=None #private member\n",
" \n",
" def __init__(self):\n",
" self.__i=500 #constructor\n",
" \n",
" def SetData(self,d):\n",
" self.__i=d\n",
" \n",
" def GetData(self):\n",
" return self.__i\n",
" \n",
"#Initializing\n",
"s1=SimpleClass()\n",
"s2=SimpleClass()\n",
"print \"s1 has data: \",s1.GetData()\n",
"print \"s2 has data: \",s2.GetData()\n",
"s1.SetData(1000) #function call\n",
"s2.SetData(2000)\n",
"print \"s1 has data: \",s1.GetData(),' '\n",
"print \"s2 has data: \", s2.GetData(),' '\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"s1 has data: 500\n",
"s2 has data: 500\n",
"s1 has data: 1000 \n",
"s2 has data: 2000 \n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Program Source Code 8.5, page no:217"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"class SimpleClass:\n",
" __IntegerData=None\n",
" def __init__(self,data=None):\n",
" if data==None:\n",
" self.__IntegerData=500 #default constructor\n",
" else:\n",
" self.__IntegerData=data #parameterised constructor\n",
" \n",
" def SetData(self,d):\n",
" self.__IntegerData=d\n",
" \n",
" def GetData(self):\n",
" return self.__IntegerData\n",
" \n",
"#Initializing\n",
"s1=SimpleClass()\n",
"s2=SimpleClass()\n",
"s3=SimpleClass(400)\n",
"s4=SimpleClass(600)\n",
"print \"s1 has data: \",s1.GetData(),' '\n",
"print \"s2 has data: \",s2.GetData(),' '\n",
"print \"s3 has data: \",s3.GetData(),' '\n",
"print \"s4 has data: \",s4.GetData(),' '\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"s1 has data: 500 \n",
"s2 has data: 500 \n",
"s3 has data: 400 \n",
"s4 has data: 600 \n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Program Source Code 8.6, page no:218"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"class Fraction: \n",
" def_init_num=None #private members\n",
" def_init_denom=None #private members\n",
" def __init__(self,a=0,b=1):\n",
" self.__num=a\n",
" self.__denom=b\n",
" print \"Numerator set inside constructor\",' ',n\n",
" print \"Denominator set inside constructor\",' ',d\n",
" \n",
" def SetValue(self,a,b):\n",
" self.__num=a\n",
" self.__denom=b\n",
" def GetValue(self,a,b):\n",
" a= self.__num\n",
" b= self.__denom\n",
" return a,b\n",
" \n",
" def __del__(self): #destructor\n",
" pass\n",
" \n",
"n=input(\"Enter n: \") #user input\n",
"d=input(\"Enter d: \") #user input\n",
"print \"Please enter value of numerator and denominator: \",' ',n,d\n",
"f=Fraction(n,d)\n",
"f.GetValue(n,d)\n",
"print \"Numerator value retrieved: \", ' ',n\n",
"print \"Denominator value retrieved: \", ' ',d"
],
"language": "python",
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"stream": "stdout",
"text": [
"Enter n: 3\n"
]
},
{
"name": "stdout",
"output_type": "stream",
"stream": "stdout",
"text": [
"Enter d: 4\n"
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Please enter value of numerator and denominator: 3 4\n",
"Numerator set inside constructor 3\n",
"Denominator set inside constructor 4\n",
"Numerator value retrieved: 3\n",
"Denominator value retrieved: 4\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Program Source Code 8.7, page no:221"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"class Fraction:\n",
" \n",
" def __init__(self,a=0,b=1): #constructor\n",
" self.__num=a\n",
" self.__denom=b\n",
" print \"Numerator set inside constructor: \",self.__num\n",
" print \"Denominator set inside constructor: \",self.__denom \n",
" \n",
" def GetValue(self,a,b):\n",
" return self.__num,self.__denom\n",
"n=input(\"Enter n: \") #user input\n",
"d=input(\"Enter d: \") #user input\n",
"print \"Please enter the value of the numerator and denominator: \",n,d\n",
"f=Fraction(n,d)\n",
"n,d=f.GetValue(n,d)\n",
"print \"Numerator value retrieved: \", ' ',n\n",
"print \"Denominator value retrieved: \", ' ',d\n",
"n=input(\"Please enter the value of numerator only: \")\n",
"f1=Fraction(n)\n",
"n,d=f1.GetValue(n,d)\n",
"print \"Numerator value retrieved: \", ' ',n\n",
"print \"Denominator value retrieved: \", ' ',d\n",
"print 'ok..now I will create a fraction-no input please'\n",
"f2=Fraction()\n",
"n,d=f2.GetValue(n,d)\n",
"print \"Numerator value retrieved: \", ' ',n\n",
"print \"Denominator value retrieved: \", ' ',d"
],
"language": "python",
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"stream": "stdout",
"text": [
"Enter n: 3\n"
]
},
{
"name": "stdout",
"output_type": "stream",
"stream": "stdout",
"text": [
"Enter d: 4\n"
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Please enter the value of the numerator and denominator: 3 4\n",
"Numerator set inside constructor: 3\n",
"Denominator set inside constructor: 4\n",
"Numerator value retrieved: 3\n",
"Denominator value retrieved: 4\n"
]
},
{
"name": "stdout",
"output_type": "stream",
"stream": "stdout",
"text": [
"Please enter the value of numerator only: 3\n"
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Numerator set inside constructor: 3\n",
"Denominator set inside constructor: 1\n",
"Numerator value retrieved: 3\n",
"Denominator value retrieved: 1\n",
"ok..now I will create a fraction-no input please\n",
"Numerator set inside constructor: 0\n",
"Denominator set inside constructor: 1\n",
"Numerator value retrieved: 0\n",
"Denominator value retrieved: 1\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Program Source Code 8.8, page no:223"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"class Fraction:\n",
" def_init_num=None #private members\n",
" def_init_denom=None #private members\n",
" \n",
" def __init__(self,anotherFraction=None): \n",
" if anotherFraction==None: #normal constructor\n",
" self.__num=anotherFraction\n",
" self.__denom=anotherFraction\n",
" else: #copy constructor\n",
" self.__num=anotherFraction.self.__num\n",
" self.__denom=anotherFraction.self.__denom\n",
" \n",
" \n",
" #public functions\n",
" def SetValue(self,a,b):\n",
" self.__num=a\n",
" self.__denom=b#refer to IntegerData\n",
" def GetValue(self,a,b):\n",
" a=self.__num\n",
" b=self.__denom\n",
" return a,b\n",
" \n",
"f=Fraction()\n",
"n=input(\"Enter n: \") #user input\n",
"d=input(\"Enter d: \") #user input\n",
"print \"enter the numerator and denominator: \", ' ',n,d\n",
"\n",
"f.SetValue(n,d) #call function SetValue\n",
"print \"Numerator value set: \", ' ',n\n",
"print \"Denominator value set: \", ' ',d\n",
"f.GetValue(n,d) #call function GetData\n",
"print \"Numerator value retrieved: \", ' ',n\n",
"print \"Denominator value retrieved: \", ' ',d\n",
"print \"Now a second clone copy is being created: \",''\n",
"f1=f\n",
"f1.GetValue(n,d)\n",
"print \"Clone's numerator value retrieved: \", ' ',n\n",
"print \"Clone's denominator value retrieved: \", ' ',d"
],
"language": "python",
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"stream": "stdout",
"text": [
"Enter n: 5\n"
]
},
{
"name": "stdout",
"output_type": "stream",
"stream": "stdout",
"text": [
"Enter d: 6\n"
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"enter the numerator and denominator: 5 6\n",
"Numerator value set: 5\n",
"Denominator value set: 6\n",
"Numerator value retrieved: 5\n",
"Denominator value retrieved: 6\n",
"Now a second clone copy is being created: \n",
"Clone's numerator value retrieved: 5\n",
"Clone's denominator value retrieved: 6\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Program Source Code 8.9, page no:229"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"def MyNewHandler():\n",
" print \"Sorry operator new failed to allocate memory\"\n",
" exit(0)\n",
" \n",
"def _set_new_handler(s):\n",
" s()\n",
"#In python there is no in-built _set_new_handler function, so i made this function and passed MyNewHandler function as a parameters\n",
"_set_new_handler(MyNewHandler)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Sorry operator new failed to allocate memory\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Program Source Code 8.10, page no:230"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from ctypes import * \n",
"class Fraction: \n",
" def __init__(self,a=0,b=1): \n",
" if isinstance(a,int): \n",
" c = c_int(a) \n",
" d = c_int(b) \n",
" self.__num = pointer(c) \n",
" self.__denom = pointer(d) \n",
" print 'constructor sets numerator = ', self.__num[0] , ', denominator = ', self.__denom[0] \n",
" else:\n",
" c=c_int(a.__num[0])\n",
" d = c_int(a.__denom[0])\n",
" self.__num = pointer(c) \n",
" self.__denom = pointer(d)\n",
" print 'copy constructor sets numerator = ', self.__num[0] , ', denominator = ', self.__denom[0] \n",
" \n",
" def __del__(self): \n",
" print 'destructor deallocates numerator = ', self.__num[0] , ', denominator = ', self.__denom[0] \n",
" \n",
"n = input(\"Please enter values of numerator: \") \n",
"d = input(\"Please enter values of denominator: \") \n",
"f = Fraction(n,d) \n",
"print 'Please enter another set of ' \n",
"n = input(\"numerator: \") \n",
"d = input(\"denominator: \") \n",
"print 'Creating fraction *pf : ' \n",
"pf = Fraction(n,d) \n",
"print 'Now a clone copy (f2) created from *pf: ' \n",
"f2 = Fraction(pf)\n",
"print 'Now another clone copy (*pf2) created from f:' \n",
"pf2 = Fraction(f) \n",
"print '*pf2 is being destroyed:' \n",
"del pf2\n",
"print '*pf is being destroyed:' \n",
"del pf \n",
"print 'now objects f2 and f automatically destroyed : '"
],
"language": "python",
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"stream": "stdout",
"text": [
"Please enter values of numerator: 3\n"
]
},
{
"name": "stdout",
"output_type": "stream",
"stream": "stdout",
"text": [
"Please enter values of denominator: 4\n"
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"constructor sets numerator = 3 , denominator = 4\n",
"Please enter another set of \n"
]
},
{
"name": "stdout",
"output_type": "stream",
"stream": "stdout",
"text": [
"numerator: 5\n"
]
},
{
"name": "stdout",
"output_type": "stream",
"stream": "stdout",
"text": [
"denominator: 6\n"
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Creating fraction *pf : \n",
"constructor sets numerator = 5 , denominator = 6\n",
"Now a clone copy (f2) created from *pf: \n",
"copy constructor sets numerator = 5 , denominator = 6\n",
"Now another clone copy (*pf2) created from f:\n",
"copy constructor sets numerator = 3 , denominator = 4\n",
"*pf2 is being destroyed:\n",
"*pf is being destroyed:\n",
"now objects f2 and f automatically destroyed : \n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Program Source Code 8.11, page no:234"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"def Memfail(self,s):\n",
" print \"Sorry Unable to allocate memory\"\n",
" sys.exit(0)\n",
"\n",
"MAX_SIZE = 60 + 1\n",
"\n",
"MAX_SIZE=[[0 for col in range(MAX_SIZE)]for row in range(MAX_SIZE)]\n",
"nChar=0\n",
"chArr=\"Hello\"\n",
"\n",
"print \"Please input a string( 60 characters max.): \",chArr\n",
"\n",
"nChar=len(chArr)+1\n",
"szStr=chArr\n",
"print \"required memory space for\",nChar,\n",
"print \"characters\"\n",
"chArr=szStr #string copy\n",
"szStr=chArr\n",
"print \"String copied in allocated space: \",szStr\n",
"print \"Memory space dellocated\"\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Please input a string( 60 characters max.): Hello\n",
"required memory space for 6 characters\n",
"String copied in allocated space: Hello\n",
"Memory space dellocated\n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Program Source Code 8.12, page no:236"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"class Fraction:\n",
" \n",
" def __init__(self,a=0,b=1): #constructor\n",
" self.__num=a\n",
" self.__denom=b\n",
" \n",
" def __del__(self): #destructor\n",
" pass\n",
" \n",
" def GetValue(self,a,b):\n",
" a=self.__num\n",
" b=self.__denom\n",
" return self.__num,self.__denom\n",
"n=4\n",
"d=5\n",
"f=Fraction(4,5)\n",
"n,d=f.GetValue(n,d)"
],
"language": "python",
"metadata": {},
"outputs": [],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Program Source Code 8.13, page no:239"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"class X:\n",
" __sa=20 #initialising static member\n",
" a = None\n",
" def __init__(self):\n",
" self.a=None #public member\n",
" def f(self,b):\n",
" a=30\n",
" print \"Global a= \",b\n",
" print \"Local a= \",a\n",
" print \"Nonstatic member a= \",self.a\n",
" print \"static member sa= \",self.__sa\n",
"\n",
"a=10\n",
"\n",
"aXobj=X()\n",
"aXobj.a=40\n",
"aXobj.f(a)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Global a= 10\n",
"Local a= 30\n",
"Nonstatic member a= 40\n",
"static member sa= 20\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "code",
"collapsed": false,
"input": [],
"language": "python",
"metadata": {},
"outputs": []
}
],
"metadata": {}
}
]
}