python achieve simple calculator

re module

Import Re
 from functools Import the reduce 

DEF mul_div (exp): # of multiplication or division of two numbers 
    IF  ' * '  in exp: 
        A, B = exp.split ( ' * ' )
         return a float (A) * a float (B)
     IF  ' / '  in exp: 
        A, B = exp.split ( ' / ' )
         return a float (A) / a float (B) 

DEF exp_fmt (exp):
     the while the re.search ( '[+-]{2,}',exp):
        exp = exp.replace('--','+')
        exp = exp.replace('+-','-')
        exp = exp.replace('-+','-')
        exp = exp.replace('++','+')
    return exp

def remove_addsub(exp):
    ret = re.findall(' ? - (?.: \ \ D +)? [+] \ D + ' , exp) 
    RES = the reduce ( the lambda A, B: a float (A) + a float (B), RET)
     return RES 

DEF remove_muldiv (exp):    # calculate all multiplication and division expression 
    the while True: 
        RET = the re.search ( ' .??. \ D + (\ \ D +) [* /] - \ D + (\ \ D +)? ' , exp)
         IF RET : 
            son_exp = ret.group ()    # . 3. 4 *. 5 * 12 is 
            RES = mul_div (son_exp) 
            exp = exp.replace (son_exp, STR (RES))
         the else : returnexp 

DEF CAL (exp): 
    RES = remove_muldiv (exp)    # computation is in 
    RES = exp_fmt (RES)                   # sign finishing 
    RET = remove_addsub (RES)             # calculating subtraction 
    return RET 

DEF main (exp): 
    exp = exp.replace ( '  ' , ' ' )
     the while True: 
        RET = the re.search ( ' \ ([^ ()] + \) ' , exp)
         IF RET: 
            RES = CAL (ret.group ()) 
            exp = exp.replace(ret.group(), str(res))
        else: return cal(exp)

exp = '1 - 2 * ( (60-30 +(-40/5) * (9-2*5/3 + 7 /3*99/4*2998 +10 * 568/14 )) - (-4*3)/ (16-3*2) )'
ret = main(exp)
print(ret)