def starts_with(prefix):
    """
    Returns a function calling startswith using the given prefix on a given value.

    >>> starts_with('abc')('abc123')
    True
    >>> starts_with('123')('abc123')
    False

    :param prefix: Prefix to check
    :return: Function
    """

    def _starts_with(s):
        return s.startswith(prefix)

    return _starts_with