The registered user python function register ()

db_path = 'db.txt' # define the default file path, easy to modify 
DEF get_uname (): 
    the while True: 
        uname = the INPUT ( 'Please enter your user name:') Strip (). 
        IF uname.isalpha (): 
            with Open (r '% S'% (DB_PATH), 'R & lt', encoding = 'UTF-. 8') AS F: 
                for I in F: 
                    . unifo = i.strip ( '\ n-') Split ( ',') 
                    Print (unifo ) # View the discovery process 
                    IF uname == unifo [0]: 

                        Print ( 'user already exists, please re-enter') 
                        BREAK 
                the else: 
                    return uname 
        the else: 
            Print ( 'user name must be Chinese or the letter') 
DEF get_pwd (): 
    while True:
        pwd1 = input ( 'Enter password:') strip ().
        pwd2 = input ( 'Please enter the password again:') Strip (). 
        IF pwd1 == pwd2: 
            return pwd1 
        the else: 
            Print ( 'password twice inconsistent input, please re-enter ...') 
DEF get_bal (): 
    the while True: 
        BAL = the iNPUT ( 'Please enter the balance:') 
        IF bal.isdecimal (): 
            return BAL 
        the else: 
            Print ( 'money is digital, sucker ...') 
DEF file_hanle (uname, pwd, BAL): 
     with Open ( R & lt '% S'% (DB_PATH), 'A', encoding = 'UTF-. 8') AS F: 
         f.write ( '% S,% S,% S \ n-'% (the uname, pwd, BAL)) 
the Register DEF (): 
    uname = get_uname () # get valid user name 
    pwd = get_pwd () # get a legitimate password 
    bal = get_bal () # get a legitimate balance 
    file_hanle (uname, pwd,bal) # write to file

register()