join.py

"""
Program to join a list of strings with a separator
"""


def join(separator: str, separated: list[str]) -> str:
    """
    Joins a list of strings using a separator
    and returns the result.

    :param separator: Separator to be used
                for joining the strings.
    :param separated: List of strings to be joined.

    :return: Joined string with the specified separator.

    Examples:

    >>> join("", ["a", "b", "c", "d"])
    'abcd'

    >>> join("#", ["a", "b", "c", "d"])
    'a#b#c#d'

    Single-element list:
    >>> join("#", ["a"])
    'a'

    Joining with space as a separator:
    >>> join(" ", ["You", "are", "amazing!"])
    'You are amazing!'

    This example should raise an exception for non-string elements:
    >>> join("#", ["a", "b", "c", 1])
    Traceback (most recent call last):
        ...
    Exception: join() accepts only strings

    Additional test case with a different separator:
    >>> join("-", ["apple", "banana", "cherry"])
    'apple-banana-cherry'

    Handling a list with empty strings:
    >>> join(",", ["", "", ""])
    ',,'
    """
    # Ensure all elements in the list are strings
    if not all(isinstance(item, str) for item in separated):
        raise Exception("join() accepts only strings")

    # Use Python's built-in join method for simplicity and correctness
    return separator.join(separated)



if __name__ == "__main__":
    from doctest import testmod

    testmod()