def coordinates_string(coordinates_list):
    """
    This function transforms the list of coordinates to string.

    :param coordinates_list:    list
                                the list has float coordinate values
                                in this order:
                                [min_lon, min_lat, max_lon, max_lat]

    :return:                    String
                                "min_lon, min_lat, max_lon, max_lat"
    """
    string_coordinates = str(coordinates_list[0])
    for i, item in enumerate(coordinates_list[1:]):
        string_coordinates += ",{0}".format(str(item))
    return string_coordinates