BCA SEM 5 Python Important Programs For Practical

Python SEM - 5

1) Write a program to swap two numbers without taking a temporary variable.
ANS:

a = 10
b = 20
print("value of a is = " + a +"value of b = " + b)
a, b = b, a
print("Updated value of a is = " + a + "Updated value of b = " + b)

2) Write a program to create a Student class with name, age and marks as data members. Also create a method named display() to view the student details. Create an object to Student class and call the method using the object.
ANS:

class Student:

    def __init__(self):

        self.name = "Ramesh"

        self.age = 20

        self.marks= 90

    def display (self):

        print("Hello " + self.name)

        print("Age : " , self.age)

        print("Marks : ", self.marks)

s1 = Student()

s1.display()

3) Write a program to understand various methods of array class mentioned: append, insert, remove, pop, index, tolist and count.

ANS: 

from array import*

a = array("i",[1,2,3,4,2,5,2,6,7,8])

print("Element in Array a is ",a)

a.append(10)

print("After append method :")

a.insert(4,9)

print("After Insert method : ",a)

a.remove(9)

print("After Remove method :",a)

a.pop()

print("after pop method ",a)

print("Index of element 6 is : ", a.index(6))

print("Total occurrence of 2 : " , a.count(2))

b = a.tolist()

print ("Type of B is :", type(b))

print("Element of b is :",b)

4) Write a program to handle some built in exceptions like ZeroDivisionError.

ANS :

try:

    a=int(input("Enter value of a = "))

    b =int(input("Enter value of b = "))

    c = a/b

    print("Division of a and b is :",c)

except ZeroDivisionError:

    print("ZeroDivsionError Occurred")

5) Write a program to find out and display the common and the non-common elements in the list using membership operators

ANS)

list1=[1,2,3,4,5,4,3,6,7,8]

common=[]

nonCommon=[]

for i in list1:

    if(list1.count(i)>1):

        common.append(i)

    else:

        nonCommon.append(i)

print("Common Elements in the list are: ",set(common))

print("Non Common Elements in the list are:",nonCommon)

6) Write a program to create Student class with a constructor having more than one parameter.

class Student:
    def __init__(self,sname='',sage=0,smarks=0):
        self.name = sname
        self.age = sage
        self.marks= smarks
    def display (self):

        print("-----------------")

        print("Hello " + self.name)
        print("Age : " , self.age)
        print("Marks : ", self.marks)

sname = input("Enter Your Name : ")
sage = int(input("Enter Your Age : "))
smarks = int(input("Enter Your Marks : "))

s1 = Student()
s1.display()
s2 = Student(sname,sage,smarks)
s2.display()

7) Write a python program that removes any repeated items from a list so that each item appears at most once. For instance, the list [1,1,2,3,4,3,0,0] would become [1,2,3,4,0]. 

ANS:

lst = []

n = int(input("How many number u want:"))

for i in range(n):

    lst.append(int(input("Enter elements:")))

   

print("List : ",lst)

lst2 = set(lst)

lst2 = list(lst2) # this line convert set # into list if needed

print("List with unique values : ",lst2)

8) Write a program to import “os” module and to the current working directory and returns a list of all module functions

ANS:

import os 

print("\nCurrent Working Directory is :",os.getcwd()) 

print("\nMethods of OS Modules are :\n", dir(os))

9) Write a program that evaluates an expression given by the user at run time using eval() function. Example: Enter and expression: 10+8-9*2-(10*2) Result: -20 

ANS:

a = input("Enter Math Function to Evaluate:") 

b = eval(a) 

print ("The result of you Enter Maths function is :",b)

10) Write a program to implement single inheritance in which two sub classes are derived from a single base class.

ANS)
class Bank(object): 

    cash=5000000 

    @classmethod 

    def available_cash(cls): 

    print(cls.cash) 

class AndraBank(Bank): 

    pass

class StateBank(Bank): 

    cash=2000000 

    @classmethod 

    def available_cash(cls):

    print(cls.cash+Bank.cash) 

a=AndraBank() 

a.available_cash() 

s=StateBank()

s.available_cash()  

11) Write a lambda/Anonymous function to find bigger number in two given numbers.
ANS:

c=lambda x,y : x if x>y else y

a,b=[int(i) for i in input("Enter two numbers:").split()]

print(c(a,b),"is biggest")

12) Write a python program that asks the user to enter a length in centimeters. If the user enters a negative length, the program should tell the user that the entry is invalid. Otherwise, the program should convert the length to inches and print out the result. (2.54 = 1 inch).
ANS:

cm = int(input("Enter length in cm : "))

if cm < 0: 

    print("invalid entry") 

else: 

    print(cm/2.54, "inches")

13) Write a program to understand the order of execution of methods in several base classes according to method resolution order (MRO).

ANS:

class A(object): 

    def method(self

        print('A class method') 

        super().method() 

class B(object): 

    def method(self): 

        print('B class method') 

        super().method() 

class C(object): 

    def method(self): 

        print('C class method') 

class X(A, B): 

    def method(self): 

        print('X class method') 

        super().method() 

class Y(B, C): 

    def method(self): 

        print('Y class method') 

        super().method() 

class P(X, Y, C): 

    def method(self): 

        print('P class method') 

        super().method() 

p=P() 

p.method() 

print(p.mro()) 

14) Create a sample list of 7 elements and implement the List methods mentioned: append, insert, copy, extend, count, remove, pop, sort, reverse and clear. 

ANS:

lst=[1,2,3,4,5,6,7]

print("Element in list are:",lst)

lst.insert(7,8)

print("Element in list after insert are:",lst)

lst1=lst.copy()

print("Element in new list after coping are:",lst1)

lst.extend(lst1)

print("Elements in list after extend",lst)

print("1 occures in list",lst.count(1),"times")

lst.remove(5)

print("After removing element:",lst)

print("Removing last element",lst.pop())

lst.sort()

print("After sorting list :",lst)

lst.reverse()

print("After reversing:",lst)

lst.clear()

print("After cleat method list:",lst)

15) Write a program to handle multiple exceptions like SyntaxError and TypeError
ANS:

try: 

    date=eval(input("Enter Date:")) 

    print(date) 

    a=[1,2,3,4,5,6]

    b=[] 

    c=a/b 

    print(c) 

except TypeError: 

    print("Cannot Divide by empty list") 

except SyntaxError: 

    print("Invalid Date")

16) Write a program to search an element in the list using for loop and also demonstrate the use of “else” suite with for loop.

ANS:

lst=[1,2,3,4,5,6,7,8]

print(lst)

val=int(input("Enter element to search:"))

flag=0

for i in lst:

    if i == val:

        print("Position:",lst.index(i))

        flag=1

        break

if(flag==1):

    print("Element found")

else:

    print("Element not found")

17) Write a program to create a static method that counts the number of instances created for a class.

ANS:

class Myclass: 

    n=0 

    def __init__(self): 

        Myclass.n+=1 

    @staticmethod

    def noObjects():

        print('No. of instances created: ', Myclass.n) 

obj1=Myclass() 

obj2=Myclass() 

obj3=Myclass() 

Myclass.noObjects()

18) Write a program to convert the elements of two lists into key-value pairs of a dictionary 

ANS:

keys = ["Hey","Hello","Hii"]
value = [1,2,3]
d = dict(zip(keys , value))
print(d)