Text-based User Interface: When your program first runs, it will ask the user to log in by providing a phone number as follows. In your code, at least, the following users should already be defined (needless to say, users must be kept in a data structure) with username, balance, and phone number. You may want to include additional users in your system to practice the subjects in more depth.
'abbas', 5.4, '5577'
'betul', 3.2, '5466'
'omer', 6.4, '5551'
(Please use the most proper data structure to store username/balance/phone number information. Hint: Consider a dictionary).