spaCy/spacy/lookups.py
Ines Montani f2c8b1e362 Simplify lookup hashing
Just use get_string_id, which already does everything ensure_hash was supposed to do
2019-09-18 20:24:41 +02:00

271 lines
8.4 KiB
Python

# coding: utf-8
from __future__ import unicode_literals
import srsly
from collections import OrderedDict
from preshed.bloom import BloomFilter
from .errors import Errors
from .util import SimpleFrozenDict, ensure_path
from .strings import get_string_id
class Lookups(object):
"""Container for large lookup tables and dictionaries, e.g. lemmatization
data or tokenizer exception lists. Lookups are available via vocab.lookups,
so they can be accessed before the pipeline components are applied (e.g.
in the tokenizer and lemmatizer), as well as within the pipeline components
via doc.vocab.lookups.
"""
def __init__(self):
"""Initialize the Lookups object.
RETURNS (Lookups): The newly created object.
DOCS: https://spacy.io/api/lookups#init
"""
self._tables = OrderedDict()
def __contains__(self, name):
"""Check if the lookups contain a table of a given name. Delegates to
Lookups.has_table.
name (unicode): Name of the table.
RETURNS (bool): Whether a table of that name is in the lookups.
"""
return self.has_table(name)
def __len__(self):
"""RETURNS (int): The number of tables in the lookups."""
return len(self._tables)
@property
def tables(self):
"""RETURNS (list): Names of all tables in the lookups."""
return list(self._tables.keys())
def add_table(self, name, data=SimpleFrozenDict()):
"""Add a new table to the lookups. Raises an error if the table exists.
name (unicode): Unique name of table.
data (dict): Optional data to add to the table.
RETURNS (Table): The newly added table.
DOCS: https://spacy.io/api/lookups#add_table
"""
if name in self.tables:
raise ValueError(Errors.E158.format(name=name))
table = Table(name=name, data=data)
self._tables[name] = table
return table
def get_table(self, name):
"""Get a table. Raises an error if the table doesn't exist.
name (unicode): Name of the table.
RETURNS (Table): The table.
DOCS: https://spacy.io/api/lookups#get_table
"""
if name not in self._tables:
raise KeyError(Errors.E159.format(name=name, tables=self.tables))
return self._tables[name]
def remove_table(self, name):
"""Remove a table. Raises an error if the table doesn't exist.
name (unicode): Name of the table to remove.
RETURNS (Table): The removed table.
DOCS: https://spacy.io/api/lookups#remove_table
"""
if name not in self._tables:
raise KeyError(Errors.E159.format(name=name, tables=self.tables))
return self._tables.pop(name)
def has_table(self, name):
"""Check if the lookups contain a table of a given name.
name (unicode): Name of the table.
RETURNS (bool): Whether a table of that name exists.
DOCS: https://spacy.io/api/lookups#has_table
"""
return name in self._tables
def to_bytes(self, **kwargs):
"""Serialize the lookups to a bytestring.
RETURNS (bytes): The serialized Lookups.
DOCS: https://spacy.io/api/lookups#to_bytes
"""
return srsly.msgpack_dumps(self._tables)
def from_bytes(self, bytes_data, **kwargs):
"""Load the lookups from a bytestring.
bytes_data (bytes): The data to load.
RETURNS (Lookups): The loaded Lookups.
DOCS: https://spacy.io/api/lookups#from_bytes
"""
for key, value in srsly.msgpack_loads(bytes_data).items():
self._tables[key] = Table(key)
self._tables[key].update(value)
return self
def to_disk(self, path, **kwargs):
"""Save the lookups to a directory as lookups.bin. Expects a path to a
directory, which will be created if it doesn't exist.
path (unicode / Path): The file path.
DOCS: https://spacy.io/api/lookups#to_disk
"""
if len(self._tables):
path = ensure_path(path)
if not path.exists():
path.mkdir()
filepath = path / "lookups.bin"
with filepath.open("wb") as file_:
file_.write(self.to_bytes())
def from_disk(self, path, **kwargs):
"""Load lookups from a directory containing a lookups.bin. Will skip
loading if the file doesn't exist.
path (unicode / Path): The directory path.
RETURNS (Lookups): The loaded lookups.
DOCS: https://spacy.io/api/lookups#from_disk
"""
path = ensure_path(path)
filepath = path / "lookups.bin"
if filepath.exists():
with filepath.open("rb") as file_:
data = file_.read()
return self.from_bytes(data)
return self
class Table(OrderedDict):
"""A table in the lookups. Subclass of builtin dict that implements a
slightly more consistent and unified API.
Includes a Bloom filter to speed up missed lookups.
"""
@classmethod
def from_dict(cls, data, name=None):
"""Initialize a new table from a dict.
data (dict): The dictionary.
name (unicode): Optional table name for reference.
RETURNS (Table): The newly created object.
DOCS: https://spacy.io/api/lookups#table.from_dict
"""
self = cls(name=name)
self.update(data)
return self
def __init__(self, name=None, data=None):
"""Initialize a new table.
name (unicode): Optional table name for reference.
data (dict): Initial data, used to hint Bloom Filter.
RETURNS (Table): The newly created object.
DOCS: https://spacy.io/api/lookups#table.init
"""
OrderedDict.__init__(self)
self.name = name
# Assume a default size of 1M items
self.default_size = 1e6
size = len(data) if data and len(data) > 0 else self.default_size
self.bloom = BloomFilter.from_error_rate(size)
if data:
self.update(data)
def __setitem__(self, key, value):
"""Set new key/value pair. String keys will be hashed.
key (unicode / int): The key to set.
value: The value to set.
"""
key = get_string_id(key)
OrderedDict.__setitem__(self, key, value)
self.bloom.add(key)
def set(self, key, value):
"""Set new key/value pair. String keys will be hashed.
Same as table[key] = value.
key (unicode / int): The key to set.
value: The value to set.
"""
self[key] = value
def __getitem__(self, key):
"""Get the value for a given key. String keys will be hashed.
key (unicode / int): The key to get.
RETURNS: The value.
"""
key = get_string_id(key)
return OrderedDict.__getitem__(self, key)
def get(self, key, default=None):
"""Get the value for a given key. String keys will be hashed.
key (unicode / int): The key to get.
default: The default value to return.
RETURNS: The value.
"""
key = get_string_id(key)
return OrderedDict.get(self, key, default)
def __contains__(self, key):
"""Check whether a key is in the table. String keys will be hashed.
key (unicode / int): The key to check.
RETURNS (bool): Whether the key is in the table.
"""
key = get_string_id(key)
# This can give a false positive, so we need to check it after
if key not in self.bloom:
return False
return OrderedDict.__contains__(self, key)
def to_bytes(self):
"""Serialize table to a bytestring.
RETURNS (bytes): The serialized table.
DOCS: https://spacy.io/api/lookups#table.to_bytes
"""
data = [
("name", self.name),
("dict", dict(self.items())),
("bloom", self.bloom.to_bytes()),
]
return srsly.msgpack_dumps(OrderedDict(data))
def from_bytes(self, bytes_data):
"""Load a table from a bytestring.
bytes_data (bytes): The data to load.
RETURNS (Table): The loaded table.
DOCS: https://spacy.io/api/lookups#table.from_bytes
"""
loaded = srsly.msgpack_loads(bytes_data)
data = loaded.get("dict", {})
self.name = loaded["name"]
self.bloom = BloomFilter().from_bytes(loaded["bloom"])
self.clear()
self.update(data)
return self