Error met when running Notebook-1-FLE-cell_sets-gene_sets.ipynb

[WBY20]

Hi, guys!
After installing wot and its dependencies, i tried to run tutorials. But i met an error when i was running Notebook-1-FLE-cell_sets-gene_sets.ipynb from https://github.com/broadinstitute/wot/blob/master/notebooks/Notebook-1-FLE-cell_sets-gene_sets.ipynb. The error reported as follows:
AttributeError Traceback (most recent call last)
in
11
12 # Read expression matrix, cell days, and 2-d coordinates
---> 13 adata = wot.io.read_dataset(FULL_DS_PATH, obs=[days_df,coord_df])
14 unique_days = adata.obs['day'].unique()
15 unique_days = unique_days[np.isnan(unique_days) == False]

AttributeError: module 'wot' has no attribute 'io'

Even after I import wot.io manually, I got this error again.
But I can run the command line sucessfully like the commands in https://github.com/broadinstitute/wot/blob/master/notebooks/command_line_example.sh.
I don't know why and I'm looking forward to your help.
Thanks in advance!