Source code for pyrit.prompt_converter.random_capital_letters_converter

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

import logging
import random

from pyrit.models import PromptDataType
from pyrit.prompt_converter import ConverterResult, PromptConverter

logger = logging.getLogger(__name__)




class RandomCapitalLettersConverter(PromptConverter):
    """Takes a prompt and randomly capitalizes it by a percentage of the total characters."""



    def __init__(self, percentage: float = 100.0) -> None:
        """
        Initializes the converter with the specified percentage of randomization.

        Args:
            percentage (float): The percentage of characters to capitalize in the prompt. Must be between 1 and 100.
                Defaults to 100.0. This includes decimal points in that range.
        """
        self.percentage = percentage




    def input_supported(self, input_type: PromptDataType) -> bool:
        return input_type == "text"




    def output_supported(self, output_type: PromptDataType) -> bool:
        return output_type == "text"




    def is_lowercase_letter(self, char):
        """Checks if the given character is a lowercase letter."""
        return char.islower()




    def is_percentage(self, input_string):
        """Checks if the input string is a valid percentage between 1 and 100."""
        try:
            number = float(input_string)
            return 1 <= number <= 100
        except ValueError:
            return False




    def generate_random_positions(self, total_length, set_number):
        """Generates a list of unique random positions within the range of `total_length`."""
        # Ensure the set number is not greater than the total length
        if set_number > total_length:
            logger.error(f"Set number {set_number} cannot be greater than the total length which is {total_length}.")
            raise ValueError(
                f"Set number {set_number} cannot be greater than the total length which is {total_length}."
            )

        # Generate a list of unique random positions
        random_positions = random.sample(range(total_length), set_number)

        return random_positions




    def string_to_upper_case_by_percentage(self, percentage, prompt):
        """Converts a string by randomly capitalizing a percentage of its characters."""
        if not self.is_percentage(percentage):
            logger.error(f"Percentage number {percentage} cannot be higher than 100 and lower than 1.")
            raise ValueError(f"Percentage number {percentage} cannot be higher than 100 and lower than 1.")
        target_count = int(len(prompt) * (percentage / 100))
        random_positions = self.generate_random_positions(len(prompt), target_count)
        output = list(prompt)
        for pos in random_positions:
            if self.is_lowercase_letter(prompt[pos]):
                output[pos] = prompt[pos].upper()
        return "".join(output)




    async def convert_async(self, *, prompt: str, input_type: PromptDataType = "text") -> ConverterResult:
        """
        Converts the given prompt by randomly capitalizing a percentage of its characters.
        """
        if not self.input_supported(input_type):
            raise ValueError("Input type not supported")

        output = self.string_to_upper_case_by_percentage(self.percentage, prompt)
        return ConverterResult(output_text=output, output_type="text")