A simple project idea based on binary file handling (using pickle module) that manages a set of records as dictionaries written in a binary file. You can easily build on the idea and develop better projects.

One thing to be kept in mind that unlike C++ we cannot update record in the file randomly using pickle module(At least I did not find any solution). The work around used here is to download the records (dictionaries) as a list of dictionaries, modify the required dictionary and write back the each dictionary to the file (in ‘wb’ mode and not ‘ab’ mode)

import os
import pickle
os.chdir('D:/csproject')

#Accepting data for Dictionary
def insertRec():
    rollno = int(input('Enter roll number:'))
    name = input('Enter Name:')
    marks = int(input('Enter Marks'))

    #Creating the dictionary
    rec = {'Rollno':rollno,'Name':name,'Marks':marks}

    #Writing the Dictionary
    f = open('student.dat','ab')
    pickle.dump(rec,f)
    f.close()

#Reading the records
def readRec():
    f = open('student.dat','rb')
    while True:
        try:
            rec = pickle.load(f)
            print('Roll Num:',rec['Rollno'])
            print('Name:',rec['Name'])
            print('Marks:',rec['Marks'])
        except EOFError:
            break
    f.close()

#Searching a record based on Rollno
def searchRollNo(r):
    f = open('student.dat','rb')
    flag = False
    while True:
        try:
            rec = pickle.load(f)
            if rec['Rollno'] == r:
                print('Roll Num:',rec['Rollno'])
                print('Name:',rec['Name'])
                print('Marks:',rec['Marks'])
                flag = True
        except EOFError:
            break
    if flag == False:
        print('No Records found')
    f.close()
    
    
#Marks Modification for a RollNo
def updateMarks(r,m):
    f = open('student.dat','rb')
    reclst = []
    while True:
        try:
            rec = pickle.load(f)
            reclst.append(rec)
        except EOFError:
            break
    f.close()
    for i in range (len(reclst)):
        if reclst[i]['Rollno']==r:
            reclst[i]['Marks'] = m
    f = open('student.dat','wb')
    for x in reclst:
        pickle.dump(x,f)
    f.close()            

#Deleting a record based on Rollno
def deleteRec(r):
    f = open('student.dat','rb')
    reclst = []
    while True:
        try:
            rec = pickle.load(f)
            reclst.append(rec)
        except EOFError:
            break
    f.close()
    f = open('student.dat','wb')
    for x in reclst:
        if x['Rollno']==r:
            continue
        pickle.dump(x,f)
    f.close()  
    
print('Type 1 to insert rec.')
print('Type 2 to display rec.')
print('Type 3 to Search RollNo.')
print('Type 4 to update marks.')
print('Type 5 to delete a Record.')
choice = int(input('Enter you choice:'))
if choice == 1:
    insertRec()
if choice == 2:
    readRec()
if choice == 3:
    r = int(input('Enter a rollno to search:'))
    searchRollNo(r)
if choice == 4:
    r = int(input('Enter a rollno:'))
    m = int(input('Enter new Marks:'))
    updateMarks(r,m)
if choice == 5:
    r = int(input('Enter a rollno:'))
    deleteRec(r)