in the notebook I explain how I turned an epub file into a list of text, of each chapter. check out the notebook for mmore info, I recommend to open it in colab : https://github.com/ZA3karia/PDF2TEXT/blob/master/ebook_to_text.ipynb
here is a simple text extracter, followed by some basic NLP functionalities, easy to manupulate : https://github.com/ZA3karia/PDF2TEXT/blob/master/pdf_to_text.ipynb