Консервирование структурированных данных

import pickle

def file_open():
    inf = ("pickle.pkl", "rb")
    air_list = pickle.load(inf)
    inf.close()
    return air_list

def file_close(air_list):
    fout = len(air_list)
    out = open("pickle.pkl", "wb")
    pickle.dump(air_list, out, fout)
    out.close

def addAirplane(air_list):
    list1 = [[],[],[],[],[],[],[]]
    list1[0] = input("n Enter ID: ")
    list1[1] = input(" Enter destination: ")
    list1[2] = input(" Enter flight number: ")
    list1[3] = input(" Enter aircraft type: ")
    list1[4] = input(" Enter departure time: ")
    list1[5] = input(" Enter day of week: ")
    air_list.append(list1)

def delete(air_list):
    iD = int(input(" ID: "))
    del air_list[iD]

def show(air_list):
    print("t Information n")
    for i in range(len(air_list)):
        print("n ID: ", air_list[0])
        print(" Destination: ",air_list[1])
        print(" Flight number: ",air_list[2])
        print(" Aircraft type: ",air_list[3])
        print(" Departure time: ",air_list[4])
        print(" Day fo week: ",air_list[5])
        print("n")
    return

def search(list_airplanes):
    id = int(input(" Enter ID: "))
    print("n")
    for i in range(len(air_list)):
        if(id ==  int(air_list[i][0])):
            print("n ID: ", air_list[i][0])
            print(" Destination: ",air_list[i][1])
            print(" Flight number: ",air_list[i][2])
            print(" Aircraft type: ",air_list[i][3])
            print(" Departure time: ",air_list[i][4])
            print(" Day fo week: ",air_list[i][5])
            print("n")

def sorting(air_list, x):
    air_list1 = []
    m = 0
    for i in air_list:
        sotr_el = []
        sort_el.append(m)
        sort_el.append(int(i[x]))
        list_air.append(sort)
        m += 1
    air_list1.sort(key=lambda air_list1:air_list1[1])
    for i in range(len(air_list1)):
        print(" ID: ",air_list1[i][0])
        print(" Destination: ",air_list1[i][0][0])
        print(" Flight number: ",air_list1[i][0][1])
        print(" Aircraft type: ",air_list[i][0][2])
        print(" Departure time: ",air_list1[i][0][3])
        print(" Day fo week: ",air_list1[i][0][4])
        print("n")
    return

def menu():
    n = int(input("""ntMenu: n
    1. Show all the record
    2. Add record
    3. Delete record
    4. Search records
    5. Sort of records
    6. Exit

Enter your choice: """))

    return n

import pickle
from function import *

air_list = []

while True:
    air_list = file_open()
    n = menu()
   
    if (n == 1):
        show(air_list)
    if (n == 2):
        addAirplane(air_list)
    if (n == 3):
        delete(air_list)
    if (n == 4):
        search(air_list)
    if (n == 5):
        x = int(input(("n 0 - Sorting by ID,n 1 - Sorting by fligh number)n")))
        sorting(air_list, x)
    if (n == 6):
        break
    file_close(air_list)
   
input(" Press enter for exit...")