Source code for textattack.transformations.word_swaps.word_swap_qwerty

"""
Word Swap by swaps characters with QWERTY adjacent keys
----------------------------------------------------------
"""

import random

from .word_swap import WordSwap


[docs]class WordSwapQWERTY(WordSwap): def __init__( self, random_one=True, skip_first_char=False, skip_last_char=False, **kwargs ): """A transformation that swaps characters with adjacent keys on a QWERTY keyboard, replicating the kind of errors that come from typing too quickly. :param random_one: Whether to return a single (random) swap, or all possible swaps. :param skip_first_char: When True, do not modify the first character of each word. :param skip_last_char: When True, do not modify the last character of each word. >>> from textattack.transformations import WordSwapQWERTY >>> from textattack.augmentation import Augmenter >>> transformation = WordSwapQWERT() >>> augmenter = Augmenter(transformation=transformation) >>> s = 'I am fabulous.' >>> augmenter.augment(s) """ super().__init__(**kwargs) self.random_one = random_one self.skip_first_char = skip_first_char self.skip_last_char = skip_last_char self._keyboard_adjacency = { "q": [ "w", "a", "s", ], "w": ["q", "e", "a", "s", "d"], "e": ["w", "s", "d", "f", "r"], "r": ["e", "d", "f", "g", "t"], "t": ["r", "f", "g", "h", "y"], "y": ["t", "g", "h", "j", "u"], "u": ["y", "h", "j", "k", "i"], "i": ["u", "j", "k", "l", "o"], "o": ["i", "k", "l", "p"], "p": ["o", "l"], "a": ["q", "w", "s", "z", "x"], "s": ["q", "w", "e", "a", "d", "z", "x"], "d": ["w", "e", "r", "f", "c", "x", "s"], "f": ["e", "r", "t", "g", "v", "c", "d"], "g": ["r", "t", "y", "h", "b", "v", "d"], "h": ["t", "y", "u", "g", "j", "b", "n"], "j": ["y", "u", "i", "k", "m", "n", "h"], "k": ["u", "i", "o", "l", "m", "j"], "l": ["i", "o", "p", "k"], "z": ["a", "s", "x"], "x": ["s", "d", "z", "c"], "c": ["x", "d", "f", "v"], "v": ["c", "f", "g", "b"], "b": ["v", "g", "h", "n"], "n": ["b", "h", "j", "m"], "m": ["n", "j", "k"], } def _get_adjacent(self, s): s_lower = s.lower() if s_lower in self._keyboard_adjacency: adjacent_keys = self._keyboard_adjacency.get(s_lower, []) if s.isupper(): return [key.upper() for key in adjacent_keys] else: return adjacent_keys else: return [] def _get_replacement_words(self, word): if len(word) <= 1: return [] candidate_words = [] start_idx = 1 if self.skip_first_char else 0 end_idx = len(word) - (1 + self.skip_last_char) if start_idx >= end_idx: return [] if self.random_one: i = random.randrange(start_idx, end_idx + 1) candidate_word = ( word[:i] + random.choice(self._get_adjacent(word[i])) + word[i + 1 :] ) candidate_words.append(candidate_word) else: for i in range(start_idx, end_idx + 1): for swap_key in self._get_adjacent(word[i]): candidate_word = word[:i] + swap_key + word[i + 1 :] candidate_words.append(candidate_word) return candidate_words @property def deterministic(self): return not self.random_one