How do i call a recursive function in this python program where I am supposed to convert decimal numbers to hexadecimal?

Question

x=""
def main():
    Decimal=int(input("Enter a decimal value"))
    print (DecimaltoHexa(Decimal))

def HexaLetters(Hexa):

this is where the hexa gets imported here for numbers greater than 9

    if Hexa==10:
        return "A"
    elif Hexa==11:
        return "B"
    elif Hexa==12:
        return "C"
    elif Hexa==13:
        return "D"
    elif Hexa==14:
        return "E"
    elif Hexa==15:
        return "F"

def DecimaltoHexa(Decimal):

need help here as this is the body of the program, i cant use loops because i have to add a recursive function but i need help in doing that.

    global x
    y=0
    LastDigit=0
    Hexa=Decimal%16
    if Hexa>9:
        Hexa=HexaLetters(Hexa)
    Decimal=int(Decimal/16)
    if Decimal<16:
        y=-1
        LastDigit=Decimal
    x=str(Hexa)+x
    final=str(LastDigit)+x
    return (final)
    DecimaltoHexa(Decimal)
main()

Answer 1

Modify your recursive method in the following way to convert a decimal to hexa-

def main():
    Decimal=int(input("Enter a decimal value"))
    print (DecimaltoHexa(Decimal, ""))

def HexaLetters(Hexa):
    if Hexa == 10:
        return "A"
    elif Hexa == 11:
        return "B"
    elif Hexa == 12:
        return "C"
    elif Hexa == 13:
        return "D"
    elif Hexa == 14:
        return "E"
    elif Hexa == 15:
        return "F"

def DecimaltoHexa(Decimal, prev_hexa):
    remainder = Decimal % 16
    remaining_Decimal = Decimal // 16
    hexa_char = str(remainder)
    if remainder > 9:
        hexa_char = HexaLetters(remainder)
    current_hexa = hexa_char + prev_hexa
    if remaining_Decimal != 0:
        current_hexa = DecimaltoHexa(remaining_Decimal, current_hexa) 
    return current_hexa

main()

But if you want a more concise solution, you can use the following implementation -

hexa_chars = map(str, range(10)) + ["A", "B", "C", "D", "E", "F"]

def int_to_hexa(decimal, curr_hexa):
    rem = decimal % 16
    rem_decimal = decimal // 16
    curr_hexa = hexa_chars[rem] + curr_hexa
    if rem_decimal:
       curr_hexa = int_to_hexa(rem_decimal, curr_hexa)
    return curr_hexa

if __name__ == '__main__':
    dec = input()
    hexa_num = ""
    hexa_num = int_to_hexa(dec, hexa_num)
    print(hexa_num)