Nominatim/nominatim/tools/special_phrases/sp_csv_loader.py
2022-07-18 09:54:29 +02:00

46 lines
1.4 KiB
Python

# SPDX-License-Identifier: GPL-2.0-only
#
# This file is part of Nominatim. (https://nominatim.org)
#
# Copyright (C) 2022 by the Nominatim developer community.
# For a full list of authors see the git log.
"""
Module containing the SPCsvLoader class.
The class allows to load phrases from a csv file.
"""
from typing import Iterable
import csv
import os
from nominatim.tools.special_phrases.special_phrase import SpecialPhrase
from nominatim.errors import UsageError
class SPCsvLoader:
"""
Handles loading of special phrases from external csv file.
"""
def __init__(self, csv_path: str) -> None:
self.csv_path = csv_path
def generate_phrases(self) -> Iterable[SpecialPhrase]:
""" Open and parse the given csv file.
Create the corresponding SpecialPhrases.
"""
self._check_csv_validity()
with open(self.csv_path, encoding='utf-8') as fd:
reader = csv.DictReader(fd, delimiter=',')
for row in reader:
yield SpecialPhrase(row['phrase'], row['class'], row['type'], row['operator'])
def _check_csv_validity(self) -> None:
"""
Check that the csv file has the right extension.
"""
_, extension = os.path.splitext(self.csv_path)
if extension != '.csv':
raise UsageError(f'The file {self.csv_path} is not a csv file.')