IndexError: list index out of range

[ankush3597]

While training the model I am getting error of:

Traceback (most recent call last):
File "assimilate-train.py", line 42, in
data = data.append(blr.dataFrameFromDirectory(opts.normaldata, 'good'))
File "/Users/XXXXX/anaconda3/lib/python3.7/site-packages/pandas/core/frame.py", line 6680, in append
elif isinstance(other, list) and not isinstance(other[0], DataFrame):
IndexError: list index out of range