Roman Numeral Converter | Dataford Interview Questions

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Appfolio applications may need to display ordinal-style labels or parse legacy Roman numeral values. Implement a clean, class-based converter that supports both Roman numeral to integer and integer to Roman numeral conversions with strict validation.

Formal Specification

Create RomanNumeralConverter with a public method that accepts a value and a direction:

For direction = "to_integer", value must be a canonical uppercase Roman numeral and the method returns an integer.
For direction = "to_roman", value must be an integer from 1 through 3999 and the method returns its canonical uppercase Roman numeral.
Raise ValueError for malformed Roman numerals, unsupported directions, integers outside the allowed range, booleans, or values of the wrong type.
Provide a wrapper function named convert_roman(value, direction) that uses the class.

Canonical notation allows I, V, X, L, C, D, and M, including only valid subtractive pairs such as IV, IX, XL, XC, CD, and CM.

Constraints

Roman numeral values are limited to 1 through 3999
Input Roman numerals contain at most 15 characters
Roman numeral input must use uppercase canonical notation
Valid integer input must be an int, excluding bool
Invalid input raises ValueError

Function Signature

def convert_roman(value, direction):