I am under anaconda notebook.
I have recently installed xgboost but I cannot access XGBClassifier :
from xgboost import XGBClassifier
When I import only xgboost and write xgboost it prints that the module is here ..
The issue was that I did not install xgboost for anaconda, so writing :
conda install -c conda-forge xgboost=0.6a2
solved my problem, thank you