Introduction:

        I just came into contact with python recently. I have learned some VB language before. It may be relatively fast to get started. I have a certain foundation for computers and a good understanding of basic algorithm ideas. Time to write this program to realize the various operations of the ATM computer, and split it into the following basic modules:

1. Log in to the system

2. Register account system

3. Deposit and withdrawal operations

4. Inquiry balance system

5. Exit the system

 

General idea:

It is probably split into various modules, and then each module defines a function, and finally summarizes.

 

Problems encountered in the process:

1. The first-generation program that has just been completed has no registration function, nor does it have the function of storing user information

 

Solution: Later, I consulted Daxie’s blog and learned to introduce the json module, and create a new json module to save and store user data, so that the next time I enter the program, the data can also be inherited.

 

2. During the test, it was found that there is always a BUG error after entering the ID repeatedly during registration, which may be a logical problem

 

Solution: After introducing several variables and connecting the While loop to achieve ID repetition, the system will give a prompt: re-enter and return to the previous step of entering the ID (it has been a long time of trial and error...)

 

3. It is also a logical problem, a small BUG, ​​the password when registering should be 6 digits, and I forgot to limit it. Later, the introduction of the two variables True and False solved this BUG. I don’t know if there is a better solution. I hope the boss will give me pointers.

 

 

'''
bank ATM program
'''
import json

with open('save.json', 'r') as f:
    bankuser = json.load(f)

def save(person):
    # To save json, the read format should be written as 'w', and the content of the file can be changed.
    # Here the user data is stored in the file save.json
    with open('save.json', 'w') as f:
        json.dump(person, f) # Write this person's data, make an update
# create user
def create():
    newuser = {}
    newuser['user'] = input("hint:please enter your name:")
    x=True   # Introduce a Boolean variable of x to determine whether the ID has been registered
    z=True   # Introduce a z variable to judge whether the next step can be performed
    while z is True:
        x=True
        for user in bankuser:
            if user['user'] == newuser['user']:
                print("hint:The account has been registered")
                x=False
            
        if x==True:  # If x does not change TF, it means that the ID has not been registered, so just break out of the While loop
            break
        else:newuser['user'] = input("hint:Please re-enter your name:")  
        # If x=False, it means that the ID has been registered, enter the ID again, and then return to the previous step to compare whether it is repeated



    while x is True:  # If x is True then pre-store and password settings
        y=True  # Introduce a y variable to determine whether the bank password is 6 digits
        newuser['bank_balance'] = int(input("hint:Please enter your deposit amount:"))
        newuser['password'] = input("hint:Please enter your six-digit bank password:")
        while y is True:
            if len(newuser['password'])!= 6:  
                # If the bank password is not six, then give a prompt and re-enter the password.
                newuser['password'] = input("hint:Please enter your six-digit bank password (six digits!!!):")
            else:  # If it is six, exit this loop
                y=False
        bankuser.append(newuser)  # Add the data of this new user to the database
        save(bankuser)  # save
        x=False  # End this loop and exit the module

def login_user_system():
    #define a login system
    user_id=input("Please enter your account number:")
    user_password=input("Please enter your 6-digit password:")
    i=-1  # Database encoding starts from 0
    for user in bankuser:
        i+=1  # Initially set to 0, indicating the first item of data

        if user["user"]==user_id and user["password"]==user_password:
            print("dear{}{}，Hello, you have successfully logged in, welcome to Mihayou Bank! Please do the following!".format("vip user",user["user"]))
            print("-"*50)
            return i # Which user is given (the number of data)
    else:
        print("The password you entered is wrong, please re-enter!")

def search_money():
    """Define a function to query deposits"""
    print("Your account also has{}Yuan".format(bankuser[NewUser]["bank_balance"]))


def add_money():
    """Define a deposit function"""
    add=int(input("Please enter the amount you want to deposit:"))
    bankuser[NewUser]["bank_balance"]+=add
    print("successful deposit{}Yuan, account existing{}Yuan!".format(add,bankuser[NewUser]["bank_balance"]))

def take_money():
    """Define a withdrawal function"""
    take=int(input("Please enter the amount you want to withdraw:"))
    if take<=bankuser[NewUser]["bank_balance"]:
        bankuser[NewUser]["bank_balance"]-=take
        print("successful withdrawal{}Yuan, account existing{}Yuan!".format(take, bankuser[NewUser]["bank_balance"]))
    else:
        print("Your account balance is insufficient! Please re-enter the withdrawal balance!")

def login_out():
    """Define a function to exit the system"""
    user_choose=input("Whether to log out of the system, please press 1, if not, please press 2:")
    if user_choose=="1":
        print("You have successfully logged out, thank you for your support!")

    else:
        print("Please continue your selection!")


def welcom_system():
    print("============================================")
    print("        Welcome to Mihayou Bank Self-Service ATM system             ")
    print("============================================")


def jiemian():
    print("1.Check account                               2.deposit")
    print("3.withdraw money                                  4.Sign out")
    print("=============================================")

def dengluzhuce():
    print("1.login account                             2.Register an account")

"""user-interface"""

while True:
    welcom_system()
    dengluzhuce()
    user_key1 = input("Please enter your action:")
    if user_key1 == "1":
        NewUser = login_user_system()
        if NewUser is None:
            continue
        while True:
            jiemian()
            user_key = input("Please enter your action:")
            if user_key == "1":
                search_money()
            elif user_key == "2":
                add_money()
            elif user_key == "3":
                take_money()
            elif user_key == "4":
                save(bankuser)
                login_out()
                break
    elif user_key1 == "2":
        create()

The program runs as follows:

=======================================
          Welcome to Mihayou Bank Self-service ATM System      
=======================================
1. Login account
Please enter your action: 1
Please enter your account number: susu
Please enter your 6-digit password: 666666
Dear vip user susu, hello, you have successfully logged in, welcome to Mihayou Bank! Please do the following!
----------------------------------------—
1. Inquiry account
3.Withdrawal                                                         4. Logout
=======================================
Please enter your action: 1
You still have 4000 yuan in your account
1. Inquiry account
3.Withdrawal                                                         4. Logout
=======================================
The following is omitted

The code can be fetched and run by itself