Parses input according to pattern
    :param input:
    :param params:
    :return:

def regexp(input, **params):
    """
    Parses input according to pattern
    :param input:
    :param params:
    :return:
    """
    PARAM_FIELD_TO_PARSE = 'input.field'
    PARAM_PATTERN = 'pattern'
    PARAM_OUTPUT = 'output'
    OUT_DESC_FIELD = 'field'
    OUT_DESC_IDX = 'idx'
    OUT_DESC_TYPE = 'type'

    res = []
    regex = re.compile(params.get(PARAM_PATTERN))
    field2parse = params.get(PARAM_FIELD_TO_PARSE)
    out_desc = params.get(PARAM_OUTPUT)
    for row in input:
        matches = regex.findall(row[field2parse])[0]
        obj = {}
        for desc in out_desc:
            obj[desc[OUT_DESC_FIELD]] = Converter.convert(matches[desc[OUT_DESC_IDX]], desc[OUT_DESC_TYPE])
        res.append(obj)
    return res