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Nominatim/nominatim/tokenizer/sanitizers/clean_postcodes.py

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4.4 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.
"""
Sanitizer that filters postcodes by their officially allowed pattern.
Arguments:
convert-to-address: If set to 'yes' (the default), then postcodes that do
not conform with their country-specific pattern are
converted to an address component. That means that
the postcode does not take part when computing the
postcode centroids of a country but is still searchable.
When set to 'no', non-conforming postcodes are not
searchable either.
"""
import re
from nominatim.errors import UsageError
from nominatim.tools import country_info
class _PostcodeMatcher:
""" Matches and formats a postcode according to the format definition.
"""
def __init__(self, country_code, config):
if 'pattern' not in config:
raise UsageError("Field 'pattern' required for 'postcode' "
f"for country '{country_code}'")
pc_pattern = config['pattern'].replace('d', '[0-9]').replace('l', '[A-Z]')
self.norm_pattern = re.compile(f'\\s*(?:{country_code.upper()}[ -]?)?(.*)\\s*')
self.pattern = re.compile(pc_pattern)
self.output = config.get('output', r'\g<0>')
def match(self, postcode):
""" Match the given postcode against the postcode pattern for this
matcher. Returns a `re.Match` object if the match was successful
and None otherwise.
"""
# Upper-case, strip spaces and leading country code.
normalized = self.norm_pattern.fullmatch(postcode.upper())
if normalized:
return self.pattern.fullmatch(normalized.group(1))
return None
def normalize(self, match):
""" Return the default format of the postcode for the given match.
`match` must be a `re.Match` object previously returned by
`match()`
"""
return match.expand(self.output)
class _PostcodeSanitizer:
def __init__(self, config):
self.convert_to_address = config.get_bool('convert-to-address', True)
# Objects without a country code can't have a postcode per definition.
self.country_without_postcode = {None}
self.country_matcher = {}
for ccode, prop in country_info.iterate('postcode'):
if prop is False:
self.country_without_postcode.add(ccode)
elif isinstance(prop, dict):
self.country_matcher[ccode] = _PostcodeMatcher(ccode, prop)
else:
raise UsageError(f"Invalid entry 'postcode' for country '{ccode}'")
default_pattern = config.get('default-pattern')
if default_pattern is not None and isinstance(default_pattern, str):
self.default_matcher = _PostcodeMatcher('', {'pattern': default_pattern})
else:
self.default_matcher = None
def __call__(self, obj):
if not obj.address:
return
postcodes = ((i, o) for i, o in enumerate(obj.address) if o.kind == 'postcode')
for pos, postcode in postcodes:
formatted = self.scan(postcode.name, obj.place.country_code)
if formatted is None:
if self.convert_to_address:
postcode.kind = 'unofficial_postcode'
else:
obj.address.pop(pos)
else:
postcode.name = formatted[0]
postcode.set_attr('lookup', formatted[1])
def scan(self, postcode, country):
""" Check the postcode for correct formatting and return the
normalized version. Returns None if the postcode does not
correspond to the oficial format of the given country.
"""
if country in self.country_without_postcode:
return None
matcher = self.country_matcher.get(country, self.default_matcher)
if matcher is None:
return postcode.upper(), ''
match = matcher.match(postcode)
if match is None:
return None
return matcher.normalize(match), ' '.join(match.groups())
def create(config):
""" Create a housenumber processing function.
"""
return _PostcodeSanitizer(config)