import re


def _camel_to_snake(camel_string: str) -> str:
    """
    Use regex to change camelCased string to snake_case

    Args:
        camel_string(str)

    Returns:
        A snake_cased string

    """
    result = re.sub("(.)([A-Z][a-z]+)", r"\1_\2", camel_string)
    result = re.sub("(.)([0-9]+)", r"\1_\2", result)
    result = re.sub("([a-z0-9])([A-Z])", r"\1_\2", result)
    return result.lower()