From: Sarah Hoffmann Date: Mon, 20 Jun 2022 15:42:12 +0000 (+0200) Subject: add documentation for postcode customization X-Git-Tag: v4.1.0~22^2~5 X-Git-Url: https://git.openstreetmap.org/nominatim.git/commitdiff_plain/5be320368c6695498c4fed7cbba44220d3c91b17?ds=sidebyside add documentation for postcode customization --- diff --git a/docs/customize/Country-Settings.md b/docs/customize/Country-Settings.md new file mode 100644 index 00000000..6f8f2a9f --- /dev/null +++ b/docs/customize/Country-Settings.md @@ -0,0 +1,149 @@ +# Customizing Per-Country Data + +Whenever an OSM is imported into Nominatim, the object is first assigned +a country. Nominatim can use this information to adapt various aspects of +the address computation to the local customs of the country. This section +explains how country assignment works and the principal per-country +localizations. + +## Country assignment + +Countries are assigned on the basis of country data from the OpenStreetMap +input data itself. Countries are expected to be tagged according to the +[administrative boundary schema](https://wiki.openstreetmap.org/wiki/Tag:boundary%3Dadministrative): +a OSM relation with `boundary=administrative` and `admin_level=2`. Nominatim +uses the country code to distinguish the countries. + +If there is no country data available for a point, then Nominatim uses the +fallback data imported from `data/country_osm_grid.sql.gz`. This was computed +from OSM data as well but is guaranteed to cover all countries. + +Some OSM objects may also be located outside any country, for example a buoy +in the middle of the ocean. These object do not get any country assigned and +get a default treatment when it comes to localized handling of data. + +## Per-country settings + +### Global country settings + +The main place to configure settings per country is the file +`settings/country_settings.yaml`. This file has one section per country that +is recognised by Nominatim. Each section is tagged with the country code +(in lower case) and contains the different localization information. Only +countries which are listed in this file are taken into account for computations. + +For example, the section for Andorra looks like this: + +``` + partition: 35 + languages: ca + names: !include country-names/ad.yaml + postcode: + pattern: "(ddd)" + output: AD\1 +``` + +The individual settings are described below. + +#### `partition` + +Nominatim internally splits the data into multiple tables to improve +performance. The partition number tells Nominatim into which table to put +the country. This is purely internal management and has no effect on the +output data. + +The default is to have one partition per country. + +#### `languages` + +A comma-separated list of ISO-639 language codes of default languages in the +country. These are the languages used in name tags without a language suffix. +Note that this is not necessarily the same as the list of official languages +in the country. There may be officially recognised languages in a country +which are only ever used in name tags with the appropriate language suffixes. +Conversely, a non-official language may appear a lot in the name tags, for +example when used as an unofficial Lingua Franca. + +List the languages in order of frequency of appearance with the most frequently +used language first. It is not recommended to add languages when there are only +very few occurrences. + +If only one language is listed, then Nominatim will 'auto-complete' the +language of names without an explicit language-suffix. + +#### `names` + +List of names of the country and its translations. These names are used as +a baseline. It is always possible to search countries by the given names, no +matter what other names are in the OSM data. They are also used as a fallback +when a needed translation is not available. + +!!! Note + The list of names per country is currently fairly large because Nominatim + supports translations in many languages per default. That is why the + name lists have been separated out into extra files. You can find the + name lists in the file `settings/country-names/.yaml`. + The names section in the main country settings file only refers to these + files via the special `!include` directive. + +#### `postcode` + +Describes the format of the postcode that is in use in the country. + +When a country has no official postcodes, set this to no. Example: + +``` +ae: + postcode: no +``` + +When a country has a postcode, you need to state the postcode pattern and +the default output format. Example: + +``` +bm: + postcode: + pattern: "(ll)[ -]?(dd)" + output: \1 \2 +``` + +The **pattern** is a regular expression that describes the possible formats +accepted as a postcode. The pattern follows the standard syntax for +[regular expressions in Python](https://docs.python.org/3/library/re.html#regular-expression-syntax) +with two extra shortcuts: `d` is a shortcut for a single digit([0-9]) +and `l` for a single ASCII letter ([A-Z]). + +Use match groups to indicate groups in the postcode that may optionally be +separated with a space or a hyphen. + +For example, the postcode for Bermuda above always consists of two letters +and two digits. They may optionally be separated by a space or hyphen. That +means that Nominatim will consider `AB56`, `AB 56` and `AB-56` spelling variants +for one and the same postcode. + +Never add the country code in front of the postcode pattern. Nominatim will +automatically accept variants with a country code prefix for all postcodes. + +The **output** field is an optional field that describes what the canonical +spelling of the postcode should be. The format is the +[regular expression expand syntax](https://docs.python.org/3/library/re.html#re.Match.expand) referring back to the bracket groups in the pattern. + +Most simple postcodes only have one spelling variant. In that case, the +**output** can be omitted. The postcode will simply be used as is. + +In the Bermuda example above, the canonical spelling would be to have a space +between letters and digits. + +!!! Warning + When your postcode pattern covers multiple variants of the postcode, then + you must explicitly state the canonical output or Nominatim will not + handle the variations correctly. + +### Other country-specific configuration + +There are some other configuration files where you can set localized settings +according to the assigned country. These are: + + * [Place ranking configuration](Ranking.md) + +Please see the linked documentation sections for more information. diff --git a/docs/customize/Tokenizers.md b/docs/customize/Tokenizers.md index 19d867dd..c563b201 100644 --- a/docs/customize/Tokenizers.md +++ b/docs/customize/Tokenizers.md @@ -205,6 +205,14 @@ The following is a list of sanitizers that are shipped with Nominatim. rendering: heading_level: 6 +##### clean-postcodes + +::: nominatim.tokenizer.sanitizers.clean_postcodes + selection: + members: False + rendering: + heading_level: 6 + #### Token Analysis @@ -222,8 +230,12 @@ by a sanitizer (see for example the The token-analysis section contains the list of configured analyzers. Each analyzer must have an `id` parameter that uniquely identifies the analyzer. The only exception is the default analyzer that is used when no special -analyzer was selected. There is one special id '@housenumber'. If an analyzer -with that name is present, it is used for normalization of house numbers. +analyzer was selected. There are analysers with special ids: + + * '@housenumber'. If an analyzer with that name is present, it is used + for normalization of house numbers. + * '@potcode'. If an analyzer with that name is present, it is used + for normalization of postcodes. Different analyzer implementations may exist. To select the implementation, the `analyzer` parameter must be set. The different implementations are @@ -356,6 +368,14 @@ house numbers of the form '3 a', '3A', '3-A' etc. are all considered equivalent. The analyzer cannot be customized. +##### Postcode token analyzer + +The analyzer `postcodes` is pupose-made to analyze postcodes. It supports +a 'lookup' varaint of the token, which produces variants with optional +spaces. Use together with the clean-postcodes sanitizer. + +The analyzer cannot be customized. + ### Reconfiguration Changing the configuration after the import is currently not possible, although diff --git a/docs/mkdocs.yml b/docs/mkdocs.yml index c25ae0ad..a3860cba 100644 --- a/docs/mkdocs.yml +++ b/docs/mkdocs.yml @@ -28,6 +28,7 @@ pages: - 'Overview': 'customize/Overview.md' - 'Import Styles': 'customize/Import-Styles.md' - 'Configuration Settings': 'customize/Settings.md' + - 'Per-Country Data': 'customize/Country-Settings.md' - 'Place Ranking' : 'customize/Ranking.md' - 'Tokenizers' : 'customize/Tokenizers.md' - 'Special Phrases': 'customize/Special-Phrases.md' diff --git a/nominatim/tokenizer/sanitizers/clean_postcodes.py b/nominatim/tokenizer/sanitizers/clean_postcodes.py index 43d29769..05e90ca1 100644 --- a/nominatim/tokenizer/sanitizers/clean_postcodes.py +++ b/nominatim/tokenizer/sanitizers/clean_postcodes.py @@ -15,6 +15,10 @@ Arguments: postcode centroids of a country but is still searchable. When set to 'no', non-conforming postcodes are not searchable either. + default-pattern: Pattern to use, when there is none available for the + country in question. Warning: will not be used for + objects that have no country assigned. These are always + assumed to have no postcode. """ from nominatim.data.postcode_format import PostcodeFormatter