GDB Python pretty printer for the int datatype to Roman Numerals

roman_pp.py

#
# GDB Python pretty printer for the int datatype to Roman Numerals
#
# Ben Cohen, June 2019
#

import gdb

# GDB pretty printer for the "int" type
class IntPrinter:
    def __init__(self, val):
        self.val = val

    def to_string(self):
        ret = int_to_Roman(int(self.val))
        if ret == "":
            return "exceptis"
        else:
            return ret

def lookup_type(val):
    if str(val.type) == "int":
        return IntPrinter(val)
    return None

gdb.pretty_printers.append(lookup_type)


# Convert num to Roman numerals.
# Code from https://www.w3resource.com/python-exercises/class-exercises/python-class-exercise-1.php
# (Attribution-NonCommercial-ShareAlike 3.0 Unported licence)
def int_to_Roman(num):
    val = [
        1000, 900, 500, 400,
        100, 90, 50, 40,
        10, 9, 5, 4,
        1
        ]
    syb = [
        "M", "CM", "D", "CD",
        "C", "XC", "L", "XL",
        "X", "IX", "V", "IV",
        "I"
        ]
    roman_num = ''
    i = 0
    while  num > 0:
        for _ in range(num // val[i]):
            roman_num += syb[i]
            num -= val[i]
        i += 1
    return roman_num