Bright Tutorials Bright Tutorials
CBSE Class 12 Computer Science Question 139 of 145

File Handling — Question 19

Back to all questions
19
Question

Question 19

A binary file "Book.dat" has structure [BookNo, Book_Name, Author, Price].

(i) Write a user defined function CreateFile() to input data for a record and add to Book.dat.

(ii) Write a function CountRec(Author) in Python which accepts the Author name as parameter and count and return number of books by the given Author are stored in the binary file "Book.dat"

Answer

Let the file "Book.dat" include following data:

Book1 = [1001, Midnight's Children, Salman Rushdie, 29.99]
Book2 = [1004, A Suitable Boy, Vikram Seth, 59.9]
Book3 = [1003, The White Tiger, Aravind Adiga, 49.5]
Book4 = [1002, The Satanic Verses, Salman Rushdie, 39.23]

import pickle

def CreateFile():
        file = open("Book.dat", "ab")
        BookNo = int(input("Enter Book Number: "))
        Book_Name = input("Enter Book Name: ")
        Author = input("Enter Author Name: ")
        Price = float(input("Enter Price: "))
        record = [BookNo, Book_Name, Author, Price]
        pickle.dump(record, file)
        file.close()
    
def CountRec(authorName):
    count = 0
    found = False
    try:
        file = open("Book.dat", "rb")
        while True:
            record = pickle.load(file)
            if record[2] == authorName:
                count += 1
                found = True

    except EOFError:
        if found == False:
            print("End of file reached. No such records found.")
        else:
            print("Search successful")
        file.close()
        return count

CreateFile()
author = input("Enter Author name to count books: ")
print("Number of books by", author, ":", CountRec(author))
Output
Enter Book Number: 1008
Enter Book Name: Three Thousand Stiches
Enter Author Name: Sudha Murty
Enter Price: 200
Enter Author name to count books: Salman Rushdie
Search successful
Number of books by Salman Rushdie : 2