main.py

import pickle as p, os

def create():
    f = open('mobile.dat', 'wb')
    n = int(input("Enter no of records: "))
    print("\n")

    for k in range(n):
        mod = input("Enter model: ")
        comp = input("Enter company: ")
        price = int(input("Enter price: "))
        print("\n")

        D = {"Model": mod, "Company": comp, "Price": price}

        p.dump(D, f)

    f.close()
    print("File Created")

def tabular():
    f = open('mobile.dat', 'rb')
    print("{:<20}".format("Model"), "{:<20}".format("Company"), "{:<20}".format("Price"))

    while True:
        try:
            A = p.load(f)

            for k in A:
                print("{:<20}".format(A[k]), end=" ")
            print()

        except EOFError:
            break

    f.close()

def append():
    f = open('mobile.dat', 'ab')

    mod = input("Enter model: ")
    comp = input("Enter company: ")
    price = input("Enter price: ")
    print("\n")

    D = {"Model": mod, "Company": comp, "Price": price}

    p.dump(D, f)

    f.close()
    print("File Appended")

    tabular()

def delete():
    f = open('mobile.dat', 'rb')
    f1 = open("mobile1.dat", 'wb')

    comp = input("Enter company to check: ")

    while True:
        try:
            A = p.load(f)

            if A["Company"] != comp:
                p.dump(A, f1)
        except EOFError:
            break

    f.close()
    f1.close()

    os.remove('mobile.dat')
    os.rename('mobile1.dat', 'mobile.dat')

    tabular()

while True:
    print("\t\t\t1. Create a binary file")
    print("\t\t\t2. Display the content of the file in tabular form")
    print("\t\t\t3. Input data and append it into the binary file")
    print("\t\t\t4. Delete all details of the mobile for a given company")
    print("\t\t\t5. Kill the Program\n")

    ch = int(input("\t\t\tEnter your selection: "))
    print("\n")

    if ch == 1:
        create()

    elif ch == 2:
        tabular()

    elif ch == 3:
        append()

    elif ch == 4:
        delete()

    elif ch == 5:
        print("Thank you for using me")
        break

    else:
        print("Invalid option, Please try again")