Python 2.7: TypeError: unbound method materials() must be called with Path instance as first argument (got nothing instead)

[MarcoCode23]

Trying to run the template I got the following error message:

Traceback (most recent call last):
File "neuroTest.py", line 10, in
bio = nk.bio_process(ecg=df["ECG"], sampling_rate=100)
File "/home/sisu/anaconda2/lib/python2.7/site-packages/neurokit/bio/bio_meta.py", line 125, in bio_process
ecg = ecg_process(ecg=ecg, rsp=rsp, sampling_rate=sampling_rate, filter_type=ecg_filter_type, filter_band=ecg_filter_band, filter_frequency=ecg_filter_frequency, segmenter=ecg_segmenter, quality_model=ecg_quality_model, hrv_features=ecg_hrv_features, age=age, sex=sex, position=position)
File "/home/sisu/anaconda2/lib/python2.7/site-packages/neurokit/bio/bio_ecg.py", line 119, in ecg_process
quality = ecg_signal_quality(cardiac_cycles=processed_ecg["ECG"]["Cardiac_Cycles"], sampling_rate=sampling_rate, rpeaks=processed_ecg["ECG"]["R_Peaks"], quality_model=quality_model)
File "/home/sisu/anaconda2/lib/python2.7/site-packages/neurokit/bio/bio_ecg.py", line 357, in ecg_signal_quality
model = sklearn.externals.joblib.load(Path.materials() + 'heartbeat_classification.model')
TypeError: unbound method materials() must be called with Path instance as first argument (got nothing instead)

Is python 2.7 fully supported?

[DominiqueMakowski]

@marcofilippi, it seems like this issue is created when neurokit is trying to load the sklearn model (saved using sklearn for python 3). I am not sure that I can fix it, as it seems tied to scikitlearn 😕 Maybe try updating your version of scikit-learn?

The goal is being able to load this file... Does it work if you try only that?
model = sklearn.externals.joblib.load('heartbeat_classification.model')

[MarcoCode23]

@DominiqueMakowski , I updated to scikit-learn-0.20.3 and I tried to load the file with the command you suggested! Now the message I received is the following:

Traceback (most recent call last):
File "classes.py", line 3, in
model = sklearn.externals.joblib.load('./heartbeat_classification.model')
File "/home/sisu/anaconda2/lib/python2.7/site-packages/sklearn/externals/joblib/numpy_pickle.py", line 598, in load
obj = _unpickle(fobj, filename, mmap_mode)
File "/home/sisu/anaconda2/lib/python2.7/site-packages/sklearn/externals/joblib/numpy_pickle.py", line 526, in _unpickle
obj = unpickler.load()
File "/home/sisu/anaconda2/lib/python2.7/pickle.py", line 864, in load
dispatchkey
File "/home/sisu/anaconda2/lib/python2.7/pickle.py", line 892, in load_proto
raise ValueError, "unsupported pickle protocol: %d" % proto
ValueError: unsupported pickle protocol: 3

Which is your scikitlearn version? I suppose I cannot avoid to jump to python3, since scikit-learn website says "Scikit-learn 0.21 will require Python 3.5 or newer."