Fastai.text NameError: Name 'BaseTokenizer' Is Not Defined

I am a beginner of fastai and trying to build a model referring to Using RoBERTa with fast.ai for NLP. I was trying to customize the tokenizer (as the code below): from fastai.text

Solution 1:

Oh, I finally figure out that I should change from fastai.text import * to from fastai.text.all import *. There is no error message NameError: name 'BaseTokenizer' is not defined left.