Use panda.concat instead

[Mannilab]

When running df, info = nk.bio_process I got an error like -.DataFrame.append () and Series.append () have been deprecated and will be removed in a future version. Use pandas.concat () instead (GH35407)..etc.etc.
So I went to line 128 of epochs_create.py and replaced this
data = data.append (buffer, ignore_index = True, sort = False)
data = buffer.append (data, ignore_index = True, sort = False)
with:

data = data.concat (buffer, ignore_index = True, sort = False)
 data = buffer.concat (data, ignore_index = True, sort = False). 

The error of using concat instead of append is gone, however now, it gives the following error:
AttributeError: 'DataFrame' object has no attribute 'concat'.
Can anyone help me out? Thank you .