import hashlib


def get_md5_hash(value):
    """
    >>> get_md5_hash('hello')
    '5d41402abc4b2a76b9719d911017c592'

    >>> get_md5_hash(u'hello')
    '5d41402abc4b2a76b9719d911017c592'

    >>> get_md5_hash(u'Hé ho du bateau!')
    'ef67594ec96664e539a1ee2a8903d734'

    :param value: string to hash
    :return: md5 hash
    """
    return hashlib.md5(value.encode('utf-8')).hexdigest() if value else ''