Source code for lambeq.text2diagram.web_parser

# Copyright 2021-2023 Cambridge Quantum Computing Ltd.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
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Web parser
A parser that retrieves parses from a web server, thus forgoes the need
to have a parser installed locally.


from __future__ import annotations

__all__ = ['WebParser', 'WebParseError']

import sys

from import tqdm

from lambeq.core.globals import VerbosityLevel
from lambeq.core.utils import (SentenceBatchType, tokenised_batch_type_check,
from lambeq.text2diagram.ccg_parser import CCGParser
from lambeq.text2diagram.ccg_tree import CCGTree

    'depccg': ''

[docs]class WebParseError(OSError):
[docs] def __init__(self, sentence: str) -> None: self.sentence = sentence
def __str__(self) -> str: return (f'Web parser could not parse {repr(self.sentence)}')
[docs]class WebParser(CCGParser): """Wrapper that allows passing parser queries to an online service."""
[docs] def __init__( self, parser: str = 'depccg', verbose: str = VerbosityLevel.SUPPRESS.value) -> None: """Initialise a web parser. Parameters ---------- parser : str, optional The web parser to use. By default, this is depccg parser. verbose : str, default: 'suppress', See :py:class:`VerbosityLevel` for options. """ if parser.lower() not in SERVICE_URLS: raise ValueError(f'Unknown web parser: {parser}') self.service_url = SERVICE_URLS[parser] if not VerbosityLevel.has_value(verbose): raise ValueError(f'`{verbose}` is not a valid verbose value for ' 'WebParser.') self.verbose = verbose
[docs] def sentences2trees(self, sentences: SentenceBatchType, tokenised: bool = False, suppress_exceptions: bool = False, verbose: str | None = None) -> list[CCGTree | None]: """Parse multiple sentences into a list of :py:class:`.CCGTree` s. Parameters ---------- sentences : list of str, or list of list of str The sentences to be parsed. suppress_exceptions : bool, default: False Whether to suppress exceptions. If :py:obj:`True`, then if a sentence fails to parse, instead of raising an exception, its return entry is :py:obj:`None`. verbose : str, optional See :py:class:`VerbosityLevel` for options. If set, it takes priority over the :py:attr:`verbose` attribute of the parser. Returns ------- list of :py:class:`CCGTree` or None The parsed trees. May contain :py:obj:`None` if exceptions are suppressed. Raises ------ URLError If the service URL is not well formed. ValueError If a sentence is blank or type of the sentence does not match `tokenised` flag. WebParseError If the parser fails to obtain a parse tree from the server. """ import requests if verbose is None: verbose = self.verbose if not VerbosityLevel.has_value(verbose): raise ValueError(f'`{verbose}` is not a valid verbose value for ' 'WebParser.') if tokenised: if not tokenised_batch_type_check(sentences): raise ValueError('`tokenised` set to `True`, but variable ' '`sentences` does not have type ' '`list[list[str]]`.') sentences = [' '.join(sentence) for sentence in sentences] else: if not untokenised_batch_type_check(sentences): raise ValueError('`tokenised` set to `False`, but variable ' '`sentences` does not have type ' '`list[str]`.') sent_list: list[str] = [str(s) for s in sentences] sentences = [' '.join(sentence.split()) for sentence in sent_list] empty_indices = [] for i, sentence in enumerate(sentences): if not sentence: if suppress_exceptions: empty_indices.append(i) else: raise ValueError(f'Sentence at index {i} is blank.') for i in reversed(empty_indices): del sentences[i] trees: list[CCGTree | None] = [] if verbose == VerbosityLevel.TEXT.value: print('Parsing sentences.', file=sys.stderr) for sentence in tqdm( sentences, desc='Parsing sentences', leave=False, disable=verbose != VerbosityLevel.PROGRESS.value): params = {'sentence': sentence} try: data = requests.get(self.service_url, params=params).json() except requests.RequestException as e: if suppress_exceptions: tree = None elif type(e) == requests.JSONDecodeError: raise WebParseError(str(sentence)) from e else: raise e else: tree = CCGTree.from_json(data) trees.append(tree) for i in empty_indices: trees.insert(i, None) return trees