How to get each key an value separate in text file using python

Question

I have two problems with understanding the concept of key and value in text file using python.

The first one:

I have this file which called login.txt has the several keys and values such as:

{'ID':1, 'Username':'x', 'Password':'123','Role':'Immigration officer'}
{'ID':2, 'Username':'y', 'Password':'321','Role':'Customs officer'}

And here is my login code, it's working but it still looping each time I login with the username and password. But I need it once I logged in with any right values in the txt file to stop the loop directly, I don't know if I'm understand the concept or not. Here is the code:

def login(userinput, passinput):
    with open(login_db, 'r') as f:
        for single_line in f:
            dict_to_check = ast.literal_eval(single_line)
            username = dict_to_check['Username']
            password = dict_to_check['Password']
            role = dict_to_check['Role']

            try:
                if userinput == username:
                    if passinput == password:
                        if role == 'Immigration officer':
                            Immigration()
                        elif role == 'Customs officer':
                            Customs()
                        else:
                            print('Incorrect role you do not have the authority.')
                    else:
                        print('Password is incorrect.') #It still looping here
                else:
                    print('Incorrect username')
            except:
                print("An exception occurred")

The second problem is: I have another txt file called passenger.txt which have the following content:

{'Civil ID':'123', 'Name':'John', 'DOB':'12/12/2000', 'Gender':'Male', 'Customs fine':'', 'Status':''}
{'Civil ID':'1010', 'Name':'Sara', 'DOB':'6/10/2000', 'Gender':'Female', 'Customs fine':'', 'Status':''}

I have a code to choose a specific column with the ID after that I want to modify the Status value of this ID. Here is the code:

def Existing_passenger(ID):
    with open(passenger_db, 'r') as f:
        for single_line in f:
            dict_to_check = ast.literal_eval(single_line)
            civil_id = dict_to_check['Civil ID']
            name = dict_to_check['Name']
            dob = dict_to_check['DOB']
            gender = dict_to_check['Gender']
            customs_fine = dict_to_check['Customs fine']
            status = dict_to_check['Status']

            try:
                if ID == civil_id:
                    print("-Passenger's information-")
                    print('Name: '+name+'\nDate of birth: '+dob+'\nGender: '+gender+'\nCustoms fine: '+customs_fine+'\nStatus: '+status+'\n')
                    print('A. Arrival Approved\nB. Arrival Rejected\nC. Departure Approved\nD. Departure Rejected\nE. Go Back to previous menu')
                    status_input = input('Select one of the following options: ')

                    if status_input == 'A':
                        if status == '':
                            #What should i write here to modify its status value??
                    elif status_input == 'B':
                        print('B')
                    elif status_input == 'C':
                        print('C')
                    elif status_input == 'D':
                        print('D')
                    elif status_input == 'E':
                        print('E')
                    else:
                        print('Wrong entry, please try again.')
            except:
                print("An exception occurred")

I try to understand the right concept of the key and value pairs using text file with python programming language.

Answer 1

First one:
To stop the loop once a match is found, you should add a break statement after the correct login is found. For example:

...
if userinput == username:
    if passinput == password:
        if role == 'Immigration officer':
            Immigration()
        elif role == 'Customs officer':
            Customs()
        else:
            print('Incorrect role you do not have the authority.')
        break  # stop the loop
    else:
        print('Password is incorrect.')
else:
    print('Incorrect username')

Second one:
If the original value of passenger['Status'] is '', and you write passenger['Status'] = 'Arrival Approved', then the value of passenger['Status'] will be updated to 'Arrival Approved'.

...
if status_input == 'A':
        if status == '':
            status = 'Arrival Approved'  # modify the status value
        ...