import hashlib


def generate_pk(file_name: str) -> str:
    """
    Generates a string that represents the md5 hash of filename
    :param file_name: The file path in Dropbox to create the hash
    :return: MD5 hash to use as PK to store locally
    """
    file_path_md5 = hashlib.md5(file_name.encode())
    return file_path_md5.hexdigest()