Nominatim/nominatim/data/postcode_format.py
Paweł Wroniszewski fbe40e005d Properly validate postcodes with country code
Include postcode pattern in postcode normalisation regex, instead of
removing it from postcode pattern in config.

It properly handles postcode validation and normalization when country code
is part of the postcode, e.g. for Isle of Man, Jersey, Anguilla, Andorra,
Cayman Islands and more.

Fixes #3227.
2023-10-17 01:04:07 +02:00

115 lines
4.3 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.
"""
Functions for formatting postcodes according to their country-specific
format.
"""
from typing import Any, Mapping, Optional, Set, Match
import re
from nominatim.errors import UsageError
from nominatim.data import country_info
class CountryPostcodeMatcher:
""" Matches and formats a postcode according to a format definition
of the given country.
"""
def __init__(self, country_code: str, config: Mapping[str, Any]) -> None:
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()}[ -]?)?({pc_pattern})\\s*')
self.pattern = re.compile(pc_pattern)
self.output = config.get('output', r'\g<0>')
def match(self, postcode: str) -> Optional[Match[str]]:
""" 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: Match[str]) -> str:
""" 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 PostcodeFormatter:
""" Container for different postcode formats of the world and
access functions.
"""
def __init__(self) -> None:
# Objects without a country code can't have a postcode per definition.
self.country_without_postcode: Set[Optional[str]] = {None}
self.country_matcher = {}
self.default_matcher = CountryPostcodeMatcher('', {'pattern': '.*'})
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] = CountryPostcodeMatcher(ccode, prop)
else:
raise UsageError(f"Invalid entry 'postcode' for country '{ccode}'")
def set_default_pattern(self, pattern: str) -> None:
""" Set the postcode match pattern to use, when a country does not
have a specific pattern.
"""
self.default_matcher = CountryPostcodeMatcher('', {'pattern': pattern})
def get_matcher(self, country_code: Optional[str]) -> Optional[CountryPostcodeMatcher]:
""" Return the CountryPostcodeMatcher for the given country.
Returns None if the country doesn't have a postcode and the
default matcher if there is no specific matcher configured for
the country.
"""
if country_code in self.country_without_postcode:
return None
assert country_code is not None
return self.country_matcher.get(country_code, self.default_matcher)
def match(self, country_code: Optional[str], postcode: str) -> Optional[Match[str]]:
""" Match the given postcode against the postcode pattern for this
matcher. Returns a `re.Match` object if the country has a pattern
and the match was successful or None if the match failed.
"""
if country_code in self.country_without_postcode:
return None
assert country_code is not None
return self.country_matcher.get(country_code, self.default_matcher).match(postcode)
def normalize(self, country_code: str, match: Match[str]) -> str:
""" Return the default format of the postcode for the given match.
`match` must be a `re.Match` object previously returned by
`match()`
"""
return self.country_matcher.get(country_code, self.default_matcher).normalize(match)