error when ploting interpolated electronic band structure for the selected exciton state

[Dean]

Dear all,
I want to plot interpolated |A(v,c,k)| on the interpolated electronic band structure for the selected exciton state following, https://www.yambo-code.eu/wiki/index.ph ... _databases.
But, by using exc_kspace_plot.py, it shows an error:
"Traceback (most recent call last):
File "exc_kspace_plot.py", line 90, in <module>
exc_on_bands = yexc.interpolate(yel,path,states,lpratio=50,f=None,size=0.5,verbose=True)
File "/public/home/ding/.conda/envs/yampy/lib/python3.7/site-packages/yambopy-0.2.0-py3.7.egg/yambopy/dbs/excitondb.py", line 1068, in interpolate
from abipy.core.skw import SkwInterpolator
File "/public/home/ding/.conda/envs/yampy/lib/python3.7/site-packages/abipy/__init__.py", line 18, in <module>
from abipy.core import release
File "/public/home/ding/.conda/envs/yampy/lib/python3.7/site-packages/abipy/core/__init__.py", line 3, in <module>
from .kpoints import *
File "/public/home/ding/.conda/envs/yampy/lib/python3.7/site-packages/abipy/core/kpoints.py", line 17, in <module>
from abipy.iotools import ETSF_Reader
File "/public/home/ding/.conda/envs/yampy/lib/python3.7/site-packages/abipy/iotools/__init__.py", line 9, in <module>
from .visualizer import *
File "/public/home/ding/.conda/envs/yampy/lib/python3.7/site-packages/abipy/iotools/visualizer.py", line 8, in <module>
from monty.os.path import which
ImportError: cannot import name 'which' from 'monty.os.path' (/public/home/ding/.conda/envs/yampy/lib/python3.7/site-packages/monty/os/path.py)"
I think it is caulsed by abipy, but I did install it successfully.
By the way, the DFT code is QE(pw.x) and the uninterpolated electronic band structure with the selected exciton state is plotted successfully.
The exc_kspace_plot.py file is attached.
Any sugesstion is appreciated.
Best,