Write code to convert back and forth between Arabic numerals (e.g. 23) and strings representing Roman numerals (e.g. "XXIII").

• Python

1. Fork and clone this repository.
2. Change into the new directory.
3. Install dependencies.
4. Create and checkout a new branch to work on.
5. Fulfill the listed requirements.

For reference:

JavaScript, Ruby, and Python starter code is available in lib/challenge.js, lib/challenge.rb, and lib/challenge.py, respectively. A pull request is not required, but it is necessary if you want a code review.

You may wish to refer to FAQs related to forking, cloning.

In either Ruby or JavaScript, implement arabic_to_roman (arabicToRoman in JavaScript), a method/function that converts arabic numbers to strings of characters representing Roman numerals. It's worth noting that in Roman numerals, there is no way to represent either zero, negative numbers, or fractions, so if the input is any of these (or any other obviously invalid input), arabic_to_roman should return null/nil.

Once you've successfully met all requirements in your language of choice, implement that same solution in Python.

You should be running the appropriate linter before diagnosing any bugs, since linters find some of the most common sources of errors. After your linter passes, you should run the corresponding test command to run the included tests. Tests will tell you whether or not you've met these requirements.

You're welcome to view and work on the original challenge on CodeWars.

Once you've implemented arabic_to_roman, implement the inverse method, roman_to_arabic, in either Ruby or JavaScript. As with arabic_to_roman, you'll need to do some input validation -- if you receive any strings that don't follow the rules of Roman numerals (e.g. no more than three of the same character in a row) or are otherwise obviously invalid, return null/nil. Also: be sure to set xdescribe to describe in your test file, so that the tests for roman_to_arabic will also run.

Finally, do this process again in Python, un-hiding the appropriate tests in challenge_spec.py.

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