# Copyright (c) Microsoft Corporation. # Licensed under the MIT license. import random import re import string from typing import List, Optional from pyrit.models import PromptDataType from pyrit.prompt_converter import ConverterResult, PromptConverter class InsertPunctuationConverter(PromptConverter): """ Inserts punctuation into a prompt to test robustness. Punctuation insertion: inserting single punctuations in string.punctuation. Words in a prompt: a word does not contain any punctuation and space. "a1b2c3" is a word; "a1 2" are 2 words; "a1,b,3" are 3 words. """ default_punctuation_list = [",", ".", "!", "?", ":", ";", "-"] def __init__(self, word_swap_ratio: float = 0.2, between_words: bool = True) -> None: """ Initialize the converter with optional and word swap ratio. Args: word_swap_ratio (float): Percentage of words to perturb. Defaults to 0.2. between_words (bool): If True, insert punctuation only between words. If False, insert punctuation within words. Defaults to True. """ # Swap ratio cannot be 0 or larger than 1 if not 0 < word_swap_ratio <= 1: raise ValueError("word_swap_ratio must be between 0 to 1, as (0, 1].") self._word_swap_ratio = word_swap_ratio self._between_words = between_words def _is_valid_punctuation(self, punctuation_list: List[str]) -> bool: """ Check if all items in the list are valid punctuation characters in string.punctuation. Space, letters, numbers, double punctuations are all invalid. Args: punctuation_list (List[str]): List of punctuations to validate. Returns: bool: valid list and valid punctuations """ return all(str in string.punctuation for str in punctuation_list) async def convert_async( self, *, prompt: str, input_type: PromptDataType = "text", punctuation_list: Optional[List[str]] = None ) -> ConverterResult: """ Convert the given prompt by inserting punctuation. Args: prompt (str): The text to convert. input_type (PromptDataType): The type of input data. punctuation_list (Optional[List[str]]): List of punctuations to use for insertion. Returns: ConverterResult: A ConverterResult containing a interation of modified prompts. """ if not self.input_supported(input_type): raise ValueError("Input type not supported") # Initialize default punctuation list # If not specified, defaults to default_punctuation_list if punctuation_list is None: punctuation_list = self.default_punctuation_list elif not self._is_valid_punctuation(punctuation_list): raise ValueError( f"Invalid punctuations: {punctuation_list}." f" Only single characters from {string.punctuation} are allowed." ) modified_prompt = self._insert_punctuation(prompt, punctuation_list) return ConverterResult(output_text=modified_prompt, output_type="text") def _insert_punctuation(self, prompt: str, punctuation_list: List[str]) -> str: """ Insert punctuation into the prompt. Args: prompt (str): The text to modify. punctuation_list (List[str]): List of punctuations for insertion. Returns: str: The modified prompt with inserted punctuation from helper method. """ # Words list contains single spaces, single word without punctuations, single punctuations words = re.findall(r"\w+|[^\w\s]|\s", prompt) # Maintains indices for actual "words", i.e. letters and numbers not divided by punctuations word_indices = [i for i in range(0, len(words)) if not re.match(r"\W", words[i])] # Calculate the number of insertions num_insertions = max( 1, round(len(word_indices) * self._word_swap_ratio) ) # Ensure at least one punctuation is inserted # If there's no actual word without punctuations in the list, insert random punctuation at position 0 if not word_indices: return random.choice(punctuation_list) + prompt if self._between_words: return self._insert_between_words(words, word_indices, num_insertions, punctuation_list) else: return self._insert_within_words(prompt, num_insertions, punctuation_list) def _insert_between_words( self, words: List[str], word_indices: List[int], num_insertions: int, punctuation_list: List[str] ) -> str: """ Insert punctuation between words in the prompt. Args: words (List[str]): List of words and punctuations. word_indices (List[int]): Indices of the actual words without punctuations in words list. num_insertions (int): Number of punctuations to insert. punctuation_list (List[str]): punctuations for insertion. Returns: str: The modified prompt with inserted punctuation. """ insert_indices = random.sample(word_indices, num_insertions) # Randomly choose num_insertions indices from actual word indices. INSERT_BEFORE = 0 INSERT_AFTER = 1 for index in insert_indices: if random.randint(INSERT_BEFORE, INSERT_AFTER) == INSERT_AFTER: words[index] += random.choice(punctuation_list) else: words[index] = random.choice(punctuation_list) + words[index] # Join the words list and return a modified prompt return "".join(words).strip() def _insert_within_words(self, prompt: str, num_insertions: int, punctuation_list: List[str]) -> str: """ Insert punctuation at any indices in the prompt, can insert into a word. Args: promp str: The prompt string num_insertions (int): Number of punctuations to insert. punctuation_list (List[str]): punctuations for insertion. Returns: str: The modified prompt with inserted punctuation. """ # List of chars in the prompt string prompt_list = list(prompt) # Store random indices of prompt_list into insert_indices # If the prompt has only 0 or 1 chars, insert at the end of the prompt insert_indices = ( [1] if len(prompt_list) <= num_insertions else random.sample(range(0, len(prompt_list) - 1), num_insertions) ) for index in insert_indices: # Insert into prompt_list at the insert_indices with random punctuation from the punctuation_list prompt_list.insert(index, random.choice(punctuation_list)) return "".join(prompt_list).strip() def input_supported(self, input_type: PromptDataType) -> bool: return input_type == "text" def output_supported(self, output_type: PromptDataType) -> bool: return output_type == "text"