# Integer to roman numeral

Python, Math, String · Nov 2, 2020

Converts an integer to its roman numeral representation. Accepts value between `1`

and `3999`

(both inclusive).

- Create a lookup list containing tuples in the form of (roman value, integer).
- Use a
`for`

loop to iterate over the values in`lookup`

. - Use
`divmod()`

to update`num`

with the remainder, adding the roman numeral representation to the result.

```
def to_roman_numeral(num):
lookup = [
(1000, 'M'),
(900, 'CM'),
(500, 'D'),
(400, 'CD'),
(100, 'C'),
(90, 'XC'),
(50, 'L'),
(40, 'XL'),
(10, 'X'),
(9, 'IX'),
(5, 'V'),
(4, 'IV'),
(1, 'I'),
]
res = ''
for (n, roman) in lookup:
(d, num) = divmod(num, n)
res += roman * d
return res
```

```
to_roman_numeral(3) # 'III'
to_roman_numeral(11) # 'XI'
to_roman_numeral(1998) # 'MCMXCVIII'
```