add documentation for sanitizer interface

Also switches mkdocstrings to 0.18 with the rather unfortunate
consequence that now mkdocstrings-python-legacy is needed as well.
This commit is contained in:
Sarah Hoffmann 2022-07-28 22:00:29 +02:00
parent a8b037669a
commit 3746befd88
7 changed files with 185 additions and 50 deletions

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@ -40,7 +40,8 @@ It has the following additional requirements:
The documentation is built with mkdocs:
* [mkdocs](https://www.mkdocs.org/) >= 1.1.2
* [mkdocstrings](https://mkdocstrings.github.io/)
* [mkdocstrings](https://mkdocstrings.github.io/) >= 0.16
* [mkdocstrings-python-legacy](https://mkdocstrings.github.io/python-legacy/)
### Installing prerequisites on Ubuntu/Debian

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@ -0,0 +1,82 @@
# Writing custom sanitizer and token analysis modules for the ICU tokenizer
The [ICU tokenizer](../customize/Tokenizers.md#icu-tokenizer) provides a
highly customizable method to pre-process and normalize the name information
of the input data before it is added to the search index. It comes with a
selection of sanitizers and token analyzers which you can use to adapt your
installation to your needs. If the provided modules are not enough, you can
also provide your own implementations. This section describes how to do that.
## Using non-standard sanitizers and token analyzers
Sanitizer names (in the `step` property) and token analysis names (in the
`analyzer`) may refer to externally supplied modules. There are two ways
to include external modules: through a library or from the project directory.
To include a module from a library, use the absolute import path as name and
make sure the library can be found in your PYTHONPATH.
To use a custom module without creating a library, you can put the module
somewhere in your project directory and then use the relative path to the
file. Include the whole name of the file including the `.py` ending.
## Custom sanitizer modules
A sanitizer module must export a single factory function `create` with the
following signature:
``` python
def create(config: SanitizerConfig) -> Callable[[ProcessInfo], None]
```
The function receives the custom configuration for the sanitizer and must
return a callable (function or class) that transforms the name and address
terms of a place. When a place is processed, then a `ProcessInfo` object
is created from the information that was queried from the database. This
object is sequentially handed to each configured sanitizer, so that each
sanitizer receives the result of processing from the previous sanitizer.
After the last sanitizer is finished, the resulting name and address lists
are forwarded to the token analysis module.
Sanitizer functions are instantiated once and then called for each place
that is imported or updated. They don't need to be thread-safe.
If multi-threading is used, each thread creates their own instance of
the function.
### Sanitizer configuration
::: nominatim.tokenizer.sanitizers.config.SanitizerConfig
rendering:
show_source: no
heading_level: 6
### The sanitation function
The sanitation function receives a single object with three members:
* `place`: read-only information about the place being processed.
See PlaceInfo below.
* `names`: The current list of names for the place. Each name is a
PlaceName object.
* `address`: The current list of address names for the place. Each name
is a PlaceName object.
While the `place` member is provided for information only, the `names` and
`address` lists are meant to be manipulated by the sanitizer. If may add and
remove entries, change information within a single entry (for example by
adding extra attributes) or completely replace the list with a different one.
#### PlaceInfo - information about the place
::: nominatim.data.place_info.PlaceInfo
rendering:
show_source: no
heading_level: 6
#### PlaceName - extended naming information
::: nominatim.tokenizer.sanitizers.base.PlaceName
rendering:
show_source: no
heading_level: 6

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@ -14,10 +14,11 @@ th {
background-color: #eee;
}
/* Indentation for mkdocstrings.
div.doc-contents:not(.first) {
padding-left: 25px;
border-left: 4px solid rgba(230, 230, 230);
margin-bottom: 60px;
}*/
.doc-object h6 {
margin-bottom: 0.8em;
font-size: 120%;
}
.doc-object {
margin-bottom: 1.3em;
}

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@ -39,6 +39,7 @@ nav:
- 'Database Layout' : 'develop/Database-Layout.md'
- 'Indexing' : 'develop/Indexing.md'
- 'Tokenizers' : 'develop/Tokenizers.md'
- 'Custom modules for ICU tokenizer': 'develop/ICU-Tokenizer-Modules.md'
- 'Setup for Development' : 'develop/Development-Environment.md'
- 'Testing' : 'develop/Testing.md'
- 'External Data Sources': 'develop/data-sources.md'
@ -58,7 +59,7 @@ plugins:
- search
- mkdocstrings:
handlers:
python:
python-legacy:
rendering:
show_source: false
show_signature_annotations: false

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@ -11,8 +11,8 @@ the tokenizer.
from typing import Optional, Mapping, Any
class PlaceInfo:
""" Data class containing all information the tokenizer gets about a
place it should process the names for.
""" This data class contains all information the tokenizer can access
about a place.
"""
def __init__(self, info: Mapping[str, Any]) -> None:
@ -21,16 +21,25 @@ class PlaceInfo:
@property
def name(self) -> Optional[Mapping[str, str]]:
""" A dictionary with the names of the place or None if the place
has no names.
""" A dictionary with the names of the place. Keys and values represent
the full key and value of the corresponding OSM tag. Which tags
are saved as names is determined by the import style.
The property may be None if the place has no names.
"""
return self._info.get('name')
@property
def address(self) -> Optional[Mapping[str, str]]:
""" A dictionary with the address elements of the place
or None if no address information is available.
""" A dictionary with the address elements of the place. They key
usually corresponds to the suffix part of the key of an OSM
'addr:*' or 'isin:*' tag. There are also some special keys like
`country` or `country_code` which merge OSM keys that contain
the same information. See [Import Styles][1] for details.
The property may be None if the place has no address information.
[1]: ../customize/Import-Styles.md
"""
return self._info.get('address')
@ -38,28 +47,30 @@ class PlaceInfo:
@property
def country_code(self) -> Optional[str]:
""" The country code of the country the place is in. Guaranteed
to be a two-letter lower-case string or None, if no country
could be found.
to be a two-letter lower-case string. If the place is not inside
any country, the property is set to None.
"""
return self._info.get('country_code')
@property
def rank_address(self) -> int:
""" The computed rank address before rank correction.
""" The [rank address][1] before ant rank correction is applied.
[1]: ../customize/Ranking.md#address-rank
"""
return self._info.get('rank_address', 0)
def is_a(self, key: str, value: str) -> bool:
""" Check if the place's primary tag corresponds to the given
""" Set to True when the place's primary tag corresponds to the given
key and value.
"""
return self._info.get('class') == key and self._info.get('type') == value
def is_country(self) -> bool:
""" Check if the place is a valid country boundary.
""" Set to True when the place is a valid country boundary.
"""
return self.rank_address == 4 \
and self.is_a('boundary', 'administrative') \

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@ -14,14 +14,20 @@ from nominatim.data.place_info import PlaceInfo
from nominatim.typing import Protocol, Final
class PlaceName:
""" A searchable name for a place together with properties.
Every name object saves the name proper and two basic properties:
* 'kind' describes the name of the OSM key used without any suffixes
""" Each name and address part of a place is encapsulated in an object of
this class. It saves not only the name proper but also describes the
kind of name with two properties:
* `kind` describes the name of the OSM key used without any suffixes
(i.e. the part after the colon removed)
* 'suffix' contains the suffix of the OSM tag, if any. The suffix
* `suffix` contains the suffix of the OSM tag, if any. The suffix
is the part of the key after the first colon.
In addition to that, the name may have arbitrary additional attributes.
Which attributes are used, depends on the token analyser.
In addition to that, a name may have arbitrary additional attributes.
How attributes are used, depends on the sanatizers and token analysers.
The exception is is the 'analyzer' attribute. This apptribute determines
which token analysis module will be used to finalize the treatment of
names.
"""
def __init__(self, name: str, kind: str, suffix: Optional[str]):
@ -113,7 +119,13 @@ class SanitizerHandler(Protocol):
def create(self, config: SanitizerConfig) -> Callable[[ProcessInfo], None]:
"""
A sanitizer must define a single function `create`. It takes the
dictionary with the configuration information for the sanitizer and
returns a function that transforms name and address.
Create a function for sanitizing a place.
Arguments:
config: A dictionary with the additional configuration options
specified in the tokenizer configuration
Return:
The result must be a callable that takes a place description
and transforms name and address as reuqired.
"""

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@ -21,8 +21,8 @@ else:
_BaseUserDict = UserDict
class SanitizerConfig(_BaseUserDict):
""" Dictionary with configuration options for a sanitizer.
""" The `SanitizerConfig` class is a read-only dictionary
with configuration options for the sanitizer.
In addition to the usual dictionary function, the class provides
accessors to standard sanatizer options that are used by many of the
sanitizers.
@ -30,10 +30,16 @@ class SanitizerConfig(_BaseUserDict):
def get_string_list(self, param: str, default: Sequence[str] = tuple()) -> Sequence[str]:
""" Extract a configuration parameter as a string list.
If the parameter value is a simple string, it is returned as a
one-item list. If the parameter value does not exist, the given
default is returned. If the parameter value is a list, it is checked
to contain only strings before being returned.
Arguments:
param: Name of the configuration parameter.
default: Value to return, when the parameter is missing.
Returns:
If the parameter value is a simple string, it is returned as a
one-item list. If the parameter value does not exist, the given
default is returned. If the parameter value is a list, it is
checked to contain only strings before being returned.
"""
values = self.data.get(param, None)
@ -54,9 +60,16 @@ class SanitizerConfig(_BaseUserDict):
def get_bool(self, param: str, default: Optional[bool] = None) -> bool:
""" Extract a configuration parameter as a boolean.
The parameter must be one of the yaml boolean values or an
user error will be raised. If `default` is given, then the parameter
may also be missing or empty.
Arguments:
param: Name of the configuration parameter. The parameter must
contain one of the yaml boolean values or an
UsageError will be raised.
default: Value to return, when the parameter is missing.
When set to `None`, the parameter must be defined.
Returns:
Boolean value of the given parameter.
"""
value = self.data.get(param, default)
@ -67,15 +80,20 @@ class SanitizerConfig(_BaseUserDict):
def get_delimiter(self, default: str = ',;') -> Pattern[str]:
""" Return the 'delimiter' parameter in the configuration as a
compiled regular expression that can be used to split the names on the
delimiters. The regular expression makes sure that the resulting names
are stripped and that repeated delimiters
are ignored but it will still create empty fields on occasion. The
code needs to filter those.
""" Return the 'delimiters' parameter in the configuration as a
compiled regular expression that can be used to split names on these
delimiters.
The 'default' parameter defines the delimiter set to be used when
not explicitly configured.
Arguments:
default: Delimiters to be used, when 'delimiters' parameter
is not explicitly configured.
Returns:
A regular expression pattern, which can be used to
split a string. The regular expression makes sure that the
resulting names are stripped and that repeated delimiters
are ignored. It may still create empty fields on occasion. The
code needs to filter those.
"""
delimiter_set = set(self.data.get('delimiters', default))
if not delimiter_set:
@ -86,13 +104,22 @@ class SanitizerConfig(_BaseUserDict):
def get_filter_kind(self, *default: str) -> Callable[[str], bool]:
""" Return a filter function for the name kind from the 'filter-kind'
config parameter. The filter functions takes a name item and returns
True when the item passes the filter.
config parameter.
If the parameter is empty, the filter lets all items pass. If the
parameter is a string, it is interpreted as a single regular expression
that must match the full kind string. If the parameter is a list then
If the 'filter-kind' parameter is empty, the filter lets all items
pass. If the parameter is a string, it is interpreted as a single
regular expression that must match the full kind string.
If the parameter is a list then
any of the regular expressions in the list must match to pass.
Arguments:
default: Filters to be used, when the 'filter-kind' parameter
is not specified. If omitted then the default is to
let all names pass.
Returns:
A filter function which takes a name string and returns
True when the item passes the filter.
"""
filters = self.get_string_list('filter-kind', default)