fastai 下载了也用不了

from fastai.structured import add_datepart
add_datepart(new_data, 'Date')
new_data.drop('Elapsed', axis=1, inplace=True) #elapsed will be the time stamp

ModuleNotFoundError Traceback (most recent call last)
in
1 #create features
----> 2 from fastai.structured import add_datepart
3 add_datepart(new_data, 'Date')
4 new_data.drop('Elapsed', axis=1, inplace=True) #elapsed will be the time stamp

ModuleNotFoundError: No module named 'fastai.structured'