The root cause of this sudden up rise in " Error: No module named ‘bcolz’.” but bcolz is already installed " is jupyter_contrib_nbextensions
Look at open issue here =>
Solution:
under fastai repo =>
git pull
yes | jupyter kernelspec remove fastai
conda env remove -y -n fastai
conda env update
source activate fastai
python -m ipykernel install --user --name fastai --display-name "fastai"
source deactivate fastai
jupyter lab &