CS Practicals

This collection of cs practicals questions were collected from DAV Public School, Hehal,Ranchi and Solutions are written in python 3 .These Practicals cover various topics related to lists , tuples , dictionary , functions , searching algorithms , sorting algorithms , file I/O ,etc.

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INDEX

Serial Number	Name of practical	Date of practical	Date of submission
1.	Practical 1	14/08/2020
2.	Practical 2	18/08/2020
3.	Practical 3	22/08/2020
4.	Practical 4	28/08/2020
5.	Practical 5	24/09/2020
6.	Practical 6	12/10/2020
7.	Practical 7	26/10/2020
8.	Practical 8	4/11/2020
9.	Practical 9	6/11/2020
10.	Practical 10	6/11/2020
11.	Practical 11	10/11/2020
12.	Practical 12	13/11/2020
13.	Practical 13	23/11/2020
14.	Practical 14	24/11/2020
15.	Practical 15	27/11/2020

Practical 1

Write a program to count the number of characters in a string and generate a dictionary where the key values are all the unique characters from the string and its associated values refer its frequency.

s=input()
d={}
for i in s:
    d[i]=0
for i in s:
    d[i]+=1
print('Number of characters in the string: ',len(s))
print('Frequency of each characters: ',d)

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Practical 2

Write a program to create a list with n number of items where each item refers a tuple which consist of the data as given below: list=[('aman',45,52,62,52,63),('rahul',52,21,20,25,56),.......(stud_name,mark1,mark2,mark3,mark4,mark5)]

Find the details of those students who is securing more than 65% as their average and display the total count of such students.

l=[]
for i in range(int(input('Enter no. of students: '))):
    t=[input('Enter student\'s name: ')]
    print('Enter marks: ')
    for i in range(5):
        t.append(int(input('>')))
    l.append(tuple(t))
print('< Students who scored more than 65% >')
c=0
for t in l:
    avg=(t[1]+t[2]+t[3]+t[4]+t[5])/5
    if avg>65:
        print('Stduent\'s name:',t[0])
        print('Marks:',t[1],t[2],t[3],t[4],t[5])
        print('Average:',avg,'%')
        c+=1
print('Number of stduents to get more than 65%:',c)

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Practical 3

Write a program to enter n no. of students’s information in the form of list of tuple where each tuple consists of roll no. and its correspondingname.Example:[(1,'adya'),(2,'abhinav'),.......(roll,'name')]. Write a menu driven choice for the keys 1 and 2, where 1 is used to sequential search and 2 for binary search.

Ask a roll number from the user and search the desired information accordingly.

def LinearSearch(s):
    for i in l:
        if i[0]==s:
            return 'Desired record:'+str(i)
    return 'No matching record found!'
def BinarySearch(L,s):
    L.sort()
    ub=len(L)-1
    lb=0
    check=0

    while check==0 and lb<=ub:
        if s==L[(lb+ub)//2][0]:
            return 'Desired record:'+str(L[(lb+ub)//2])
        else:
            if s<L[(lb+ub)//2][0]:
                ub=(ub+lb)//2 -1
            else:
                lb=(lb+ub)//2 +1
    return 'No matching record found!'


l=[]
for i in range(int(input('Enter number of students: '))):
    t=(int(input('Enter roll of the student: ')),input('Enter name of the student: '))
    l.append(t)



while True:
    s=int(input('Enter roll to be searched: '))
    n=(input('Enter: \n1 for Linear Search\n2 for Binary Search\n:'))
    if n=='1':
        print(LinearSearch(s))
    elif n=='2':
        print(BinarySearch(l,s))
    else:
        print('Invalid choice!')
        break

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Practical 4

Write a program to enter n no. of students’s information in the form of list of tuple where each tuple consists of roll no. and its corresponding name. Example:[(1,'adya'),(2,'abhinav'),.......(roll,'name')]

Sort the records in ascending order by using bubble sort with respect to their corresponding roll nummbers.

def BubbleSort(l):
    for k in range(len(l)-1):
        for j in range(0,len(l)-1-k):
            if l[j][0]>l[j+1][0]:
                l[j],l[j+1]=l[j+1],l[j]
    return l

l=[]
for i in range(int(input('Enter number of students: '))):
    t=(int(input('Enter roll of the student: ')),input('Enter name of the student: '))
    l.append(t)

print('Original List: ',l)
print('Sorted List:' ,BubbleSort(l))

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Practical-5

Write a program to input n numbers of integer in a list and print the maximum even numberr present in it , if no even number is present, then print ‘No even numbers is present !’

l=[]
for i in range(int(input('Enter no. of entries: '))):
    l.append(int(input()))

evn_number=-1 #-1 is default value, will channge once an even number is found.
for i in l:
    if i%2==0 and i>evn_number:
        evn_number=i

print('No even number is present.' if evn_number==-1 else evn_number)

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Practical 6

Write a program to enter n number of registered user details in the form of dictionary, where the dictionary contain the following details {'userid':'password'}. Ask the user to search any userid, if it is not present in the dictionary then print ‘userid not registered’, other wise check the corresponding, password after asking the same from the user and print ‘logged successfully’ if the user enters the correct password otherwise print ‘incorrect password’.

d={}
for i in range(int(input('Enter number of entries: '))):
    key=input('Enter userid: ')
    d[key]=input('Enter password: ')

s_userid=input('Enter userid to search: ')
s_passwd=input('Enter password: ')
if s_userid in d:
    if s_passwd == d[s_userid]:
        print('logged successfully.')
    else:
        print('incorrect password.')
else:
    print('userid not registered')

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Practical 7

Write a program to input a list having n number of elements and print

• the sum of all prime numbers
• the sum of all odd numbers.

l=[]
for i in range(int(input('Enter no. of elements in the list: '))):
    l.append(int(input('Enter element: ')))
sum_odd=sum_prime=0
for i in l:
    j=0
    prime=True
    
    for d in range(2,i//2 +1):
        if i%d==0 or i==1:
            prime=False
    if prime:
        sum_prime+=i

    if i%2!=0:
        sum_odd+=i
    
print('sum of odd no. is: ',sum_odd)
print('sum of prime no. is: ',sum_prime)

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Practical 8

Write a program to create a function which takes 3 arguments (say a,b,ch) where a is length b is breadth and ch is choice whether to compute area or perimeter.

Note:- Use positional arguments:

• ch==1 for area
• ch==2 for perimeter

def Area_Perimeter(a,b,ch):
    """
        a(int): Length of the rectangle
        b(int): Breadth of the rectangle
        ch(int): choice
                ch==1>>Area
                ch==2>>Perimeter
        Returns area or perimeter of the rectangle.
    """
    if ch==1:
        return 'Area is '+str(a*b)
    elif ch==2:
        return 'Perimeter is '+str(2*(a+b))
    else:
        return 'Invalid choice.'
a,b,ch=int(input('a: ')),int(input('b: ')),int(input('choice: '))
print(Area_Perimeter(a,b,ch))
#help(Area_Perimeter)

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Practical 9

Write a program to create a function which takes 3 arguments (say a,b,ch) where a is length b is breadth and ch is choice whether to compute area or perimeter.

Note:- Use keyword arguments:

• ch==1 for area
• ch==2 for perimeter

def Area_Perimeter(a,b,ch):
    """
        a(int): Length of the rectangle
        b(int): Breadth of the rectangle
        ch(int): choice
                ch==1>>Area
                ch==2>>Perimeter
        Returns area or perimeter of the rectangle.
    """
    if ch==1:
        return 'Area is '+str(a*b)
    elif ch==2:
        return 'Perimeter is '+str(2*(a+b))
    else:
        return 'Invalid choice.'
x,y,choice=int(input('a: ')),int(input('b: ')),int(input('choice: '))
print(Area_Perimeter(a=x,ch=choice,b=y))
#help(Area_Perimeter)

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Practical 10

WAP to create a function which takes 3 arguments (say a,b,ch) where a is length ;b is breadth and ch is choice whether to compute area or perimeter. Note:- By default it should find area.

def Area_Perimeter(a,b,ch=1):
    """
        a(int): Length of the rectangle
        b(int): Breadth of the rectangle
        ch(int): choice
                ch==1>>Area
                ch==2>>Perimeter
        Returns area or perimeter of the rectangle.
    """
    if ch==1:
        return 'Area is '+str(a*b)
    elif ch==2:
        return 'Perimeter is '+str(2*(a+b))
    else:
        return 'Invalid choice.'
x,y,choice=int(input('a: ')),int(input('b: ')),int(input('choice: '))
print(Area_Perimeter(a=x,ch=choice,b=y))
#help(Area_Perimeter)

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Practical 11

Create a module named as shape.py which consists of three functions named as arear(),areas() and areac() for finding area of rectangle,square and circles resectively. Call all these function from another file named as check.py using accession operator.

Code for shape.py

def arear(length,breadth):
    '''
        Return area of a rectangle of given length and breadth
    '''
    return length*breadth

def areas(side):
    '''
        Return area of a square of given side
    '''
    return side**2

def areac(radius):
    '''
        Return area of a circle of given radius
    '''
    from math import pi
    return pi*radius**2

Code for check.py

import shape
print(shape.areac(15))
print(shape.arear(10,20))
print(shape.areas(4))

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Practical 12

Create a module named as shape.py which consists of three functions named as arear(),areas() and areac() for finding area of rectangle,square and circles resectively. Call all these function from another file named as check2.py without using accession operator.

Code for shape.py

def arear(length,breadth):
    '''
        Return area of a rectangle of given length and breadth
    '''
    return length*breadth

def areas(side):
    '''
        Return area of a square of given side
    '''
    return side**2

def areac(radius):
    '''
        Return area of a circle of given radius
    '''
    from math import pi
    return pi*radius**2

Code for check2.py

from shape import *
print(areac(15))
print(arear(10,20))
print(areas(4))

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Practical 13

Write a program to read a text file student.txt and count:

• How many words are there that start with a vowel

• How many line start with T

• Number of digits

Get student.txt from here

f=open('student.txt','r')
c_vowel=c_Tline=c_digits=0

for line in f.readlines():
    if line[0]=='T':
        c_Tline+=1
    for word in line.split():
        if word[0].lower() in ['a','e','i','o','u']:
            c_vowel+=1
        elif word.isdigit():
            c_digits+=1
f.close()
print('Number of lines that start with "T":',c_Tline)
print('Number of words tha start with a vowel:',c_vowel)
print('Number digits:',c_digits)

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Practical 14

Write a program to create a file named as student.txt which will contain names of n number of students.Then create another file copy.py in which copyonly those names from student.txt which starts with letter ‘A’.

Get sample of student.txt from here
Get sample of copy.txt from here

f=open('student.txt','w+')
for i in range(int(input('Enter number of students: '))):
    f.write(input('Enter name: ')+str('\n'))
f.seek(0,0)

c=open('copy.txt','w')
for i in f.readlines():
    if i[0]=='A':
        c.write(i)

c.close()
f.close()

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Practical 15

Write a program to enter the details of n number of students having their roll,age,name in the form of a nested listl=[[roll1,age,'name1'],[roll2,age2,'name2']...], dump the entire dataset in a file students.txt,then display back only those records from that file whose age is more than 16 years.

from pickle import dump,load
f=open('students.txt','w+b')
list=[]
for i in range(int(input('Number of students: '))):
    l=[int(input('Enter roll: '))]
    l.append(int(input('Enter age of roll '+str(l[0])+':')))
    l.append(input('Enter name of roll '+str(l[0])+':'))
    list.append(l)
dump(list,f)

f.seek(0,0)
data=load(f)
for record in data:
    if record[1]>16:
        print(record)
f.close()

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