Source code for forte.processors.data_augment.algorithms.character_flip_op

# Copyright 2020 The Forte Authors. All Rights Reserved.
# 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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import random
import json
from typing import Tuple, Any, Dict, Union

from import Annotation
from forte.common.configuration import Config
from forte.processors.data_augment.algorithms.single_annotation_op import (
from forte.utils import create_import_error_msg

__all__ = ["CharacterFlipOp"]

[docs]class CharacterFlipOp(SingleAnnotationAugmentOp): r""" A uniform generator that randomly flips a character with a similar looking character from a predefined dictionary imported from `"" + "augly/text/augmenters/"`. (For example: the cat drank milk -> t/-/3 c@t d12@nk m!|_1<). Args: string: input string whose characters need to be replaced, dict_path: the `url` or the path to the pre-defined typo json file, configs: prob(float): The probability of replacement, should fall in [0, 1]. """ def __init__(self, configs: Union[Config, Dict[str, Any]]) -> None: try: import requests # pylint: disable=import-outside-toplevel except ImportError as e: raise ImportError( create_import_error_msg( "requests", "data_aug", "data augment support" ) ) from e super().__init__(configs) self.dict_path = self.configs["dict_path"] try: r = requests.get(self.dict_path, timeout=30) = r.json() except requests.exceptions.RequestException: with open(self.dict_path, encoding="utf8") as json_file: = json.load(json_file) def _flip(self, char: str): r""" Flips character with similar character from input dictionary. Args: char: input character. Returns: the modified character. """ if char in return random.choice([char]) else: return char
[docs] def single_annotation_augment( self, input_anno: Annotation ) -> Tuple[bool, str]: r""" Takes in the annotated string and performs the character flip operation on it that randomly augments few characters from it based on the probability value in the configs. Args: input_anno: the input annotation. Returns: A tuple with the first element being a boolean value indicating whether the replacement happens, and the second element is the final augmented string. """ augmented_string = "" for char in input_anno.text: if char == " " or random.random() > self.configs["prob"]: augmented_string += char else: augmented_string += self._flip(char) return True, augmented_string
[docs] @classmethod def default_configs(cls) -> Dict[str, Any]: """ Returns: A dictionary with the default config for this processor. Following are the keys for this dictionary: - dict_path (str): the `url` or the path to the pre-defined typo `json` file. One example dictionary is provided at `` `/temporaryJson/main/character_flip.json` as a default value. - prob (float): The probability of replacement. This value should fall in [0, 1]. Default value is 0.1 """ return { "dict_path": ( "" + "temporaryJson/main/character_flip.json" ), "prob": 0.1, }