seaching for a library: nondeterministic letter manipulation in sentences

[Myron]

I'm looking for a non-deterministic python library for:
Given a sentence string, manipulate it such that its meaning is not changed but the letters are. (My use case is English sentences). I'm not looking for a paraphrasing library.

Eg:
- meaningful typos (not randomly changing Levenshtein distance)
--> maybe common typos on a qwerty keyboard
- different letter case
--> maybe capital first letter


Say the sentence consists of 100 letters. I want it to change from 2 to 5 letters.

I've googled but couldn't find anything. Maybe someone here knows one.

[Larz60+]

searching https://pypi.org for paraphrasing returns https://pypi.org/search/?q=paraphrasing
with a list of 88 packages matching.

[Myron]

I'm not looking for a paraphrasing library.