Source code for pyrit.prompt_converter.first_letter_converter

# Copyright (c) Microsoft Corporation.
# Licensed under the MIT license.

import re
from typing import List, Optional, Union

from pyrit.prompt_converter.word_level_converter import WordLevelConverter




class FirstLetterConverter(WordLevelConverter):
    """
    Replaces each word of the prompt with its first letter (or digit).
    Whitespace and words that do not contain any letter or digit are ignored.
    """



    def __init__(
        self,
        *,
        letter_separator=" ",
        indices: Optional[List[int]] = None,
        keywords: Optional[List[str]] = None,
        proportion: Optional[float] = None,
        regex: Optional[Union[str, re.Pattern]] = None,
    ):
        """
        Initializes the converter with the specified join value and selection parameters.

        This class allows for selection of words to convert based on various criteria.
        Only one selection parameter may be provided at a time (indices, keywords, proportion, or regex).
        If no selection parameter is provided, all words will be converted.

        Args:
            join_value (str): The string used to join characters of each word.
            indices (Optional[List[int]]): Specific indices of words to convert.
            keywords (Optional[List[str]]): Keywords to select words for conversion.
            proportion (Optional[float]): Proportion of randomly selected words to convert [0.0-1.0].
            regex (Optional[Union[str, re.Pattern]]): Regex pattern to match words for conversion.
        """
        super().__init__(
            indices=indices, keywords=keywords, proportion=proportion, regex=regex, word_split_separator=None
        )
        self.letter_separator = letter_separator




    async def convert_word_async(self, word: str) -> str:
        stripped_word = "".join(filter(str.isalnum, word))
        return stripped_word[:1]




    def join_words(self, words: list[str]) -> str:
        cleaned_words = list(filter(None, words))
        return self.letter_separator.join(cleaned_words)