Preprocessing example.

Preprocessing of the excerpt “It is difficult to live up to this kind of thing, and my thoughts drift to the auld schule-house and Domsie.”, obtained from the book Beside the Bonnie Brier Bush, by Ian Maclaren. In the column titled Initial is the original excerpt; in the next, the phrase without capital letters and stopwords; finally, in the last, the extract after tokenization and lemmatization processes.