# 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
[docs]
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 = [",", ".", "!", "?", ":", ";", "-"]
[docs]
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)
[docs]
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()
[docs]
def output_supported(self, output_type: PromptDataType) -> bool:
return output_type == "text"
