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Nominatim/nominatim/tools/special_phrases/sp_csv_loader.py

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1.6 KiB
Python

"""
Module containing the SPCsvLoader class.
The class allows to load phrases from a csv file.
"""
import csv
import os
from nominatim.tools.special_phrases.special_phrase import SpecialPhrase
from nominatim.tools.special_phrases.sp_loader import SPLoader
from nominatim.errors import UsageError
class SPCsvLoader(SPLoader):
"""
Base class for special phrases loaders.
Handle the loading of special phrases from external sources.
"""
def __init__(self, csv_path):
super().__init__()
self.csv_path = csv_path
self.has_been_read = False
def __next__(self):
if self.has_been_read:
raise StopIteration()
self.has_been_read = True
SPCsvLoader.check_csv_validity(self.csv_path)
return SPCsvLoader.parse_csv(self.csv_path)
@staticmethod
def parse_csv(csv_path):
"""
Open and parse the given csv file.
Create the corresponding SpecialPhrases.
"""
phrases = set()
with open(csv_path) as file:
reader = csv.DictReader(file, delimiter=',')
for row in reader:
phrases.add(
SpecialPhrase(row['phrase'], row['class'], row['type'], row['operator'])
)
return phrases
@staticmethod
def check_csv_validity(csv_path):
"""
Check that the csv file has the right extension.
"""
_, extension = os.path.splitext(csv_path)
if extension != '.csv':
raise UsageError('The file {} is not a csv file.'.format(csv_path))