Nominatim/nominatim/tokenizer/token_analysis/housenumbers.py
Sarah Hoffmann 51b6d16dc6 overhaul the token analysis interface
The functional split betweenthe two functions is now that the
first one creates the ID that is used in the word table and
the second one creates the variants. There no longer is a
requirement that the ID is the normalized version. We might
later reintroduce the requirement that a normalized version be available
but it doesn't necessarily need to be through the ID.

The function that creates the ID now gets the full PlaceName. That way
it might take into account attributes that were set by the sanitizers.

Finally rename both functions to something more sane.
2022-07-29 15:14:11 +02:00

71 lines
2.4 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.
"""
Specialized processor for housenumbers. Analyses common housenumber patterns
and creates variants for them.
"""
from typing import Any, List, cast
import re
from nominatim.data.place_name import PlaceName
from nominatim.tokenizer.token_analysis.generic_mutation import MutationVariantGenerator
RE_NON_DIGIT = re.compile('[^0-9]')
RE_DIGIT_ALPHA = re.compile(r'(\d)\s*([^\d\s␣])')
RE_ALPHA_DIGIT = re.compile(r'([^\s\d␣])\s*(\d)')
RE_NAMED_PART = re.compile(r'[a-z]{4}')
### Configuration section
def configure(*_: Any) -> None:
""" All behaviour is currently hard-coded.
"""
return None
### Analysis section
def create(normalizer: Any, transliterator: Any, config: None) -> 'HousenumberTokenAnalysis': # pylint: disable=W0613
""" Create a new token analysis instance for this module.
"""
return HousenumberTokenAnalysis(normalizer, transliterator)
class HousenumberTokenAnalysis:
""" Detects common housenumber patterns and normalizes them.
"""
def __init__(self, norm: Any, trans: Any) -> None:
self.norm = norm
self.trans = trans
self.mutator = MutationVariantGenerator('', (' ', ''))
def get_canonical_id(self, name: PlaceName) -> str:
""" Return the normalized form of the housenumber.
"""
# shortcut for number-only numbers, which make up 90% of the data.
if RE_NON_DIGIT.search(name.name) is None:
return name.name
norm = cast(str, self.trans.transliterate(self.norm.transliterate(name.name)))
# If there is a significant non-numeric part, use as is.
if RE_NAMED_PART.search(norm) is None:
# Otherwise add optional spaces between digits and letters.
(norm_opt, cnt1) = RE_DIGIT_ALPHA.subn(r'\1␣\2', norm)
(norm_opt, cnt2) = RE_ALPHA_DIGIT.subn(r'\1␣\2', norm_opt)
# Avoid creating too many variants per number.
if cnt1 + cnt2 <= 4:
return norm_opt
return norm
def compute_variants(self, norm_name: str) -> List[str]:
""" Compute the spelling variants for the given normalized housenumber.
Generates variants for optional spaces (marked with '').
"""
return list(self.mutator.generate([norm_name]))