#!/usr/bin/env python3
# -*- coding:utf-8 -*-
import re


# noinspection PyPep8Naming
def snake_case_to_PascalCase(s: str):
    """
    Convert snake_case string to PascalCase.
    """
    return ''.join(word.capitalize() for word in s.split('_'))


# noinspection PyPep8Naming
def PascalCase_to_snake_case(s: str):
    """
    Convert PascalCase string to snake_case.
    """
    return re.sub(r'(?<!^)(?=[A-Z])', '_', s).lower()


if __name__ == '__main__':
    print(snake_case_to_PascalCase('my_data'))
    print(PascalCase_to_snake_case('MyData'))