Create typo_mutator.py

prompt_injection/mutators/typo_mutator.py

@@ -0,0 +1,33 @@
+
+import random
+import math
+import string
+from prompt_injection.mutators.base import PromptMutator
+
+
+class TypoPromptMutator(PromptMutator):
+  def __init__(self,percentage=0.05):
+    self.percentage=percentage
+
+  def mutate(self,sample:str)->str:
+      return self.__add_typos_to_text(sample,self.percentage)
+
+  def get_name(self):
+      return f'TypoPromptMutator-{self.percentage}'
+
+  def __introduce_typos(self,word):
+      char_list = list(word)
+      i = random.randint(0, len(char_list) - 1)
+      char_list[i] = random.choice(string.ascii_lowercase)
+      return ''.join(char_list)
+
+  def __add_typos_to_text(self,text,  change_percentage=0.05):
+      words = text.split()
+      num_words = len(words)
+      num_changes = math.ceil(num_words * change_percentage)
+      words_to_change = random.sample(words, min(num_changes, num_words))
+      for i, word in enumerate(words):
+          if word in words_to_change:
+              words[i] = self.__introduce_typos(word)
+
+      return ' '.join(words)