array mismatch in stacked_generalization.py

[cosmos2006]

While executing stacked_generalization, following error appears:

Iteration [0]
Traceback (most recent call last):
File "stacked_generalization.py", line 179, in
score = run(data)
File "stacked_generalization.py", line 95, in run
X = np.array([ i[:-1] for i in data ], dtype=float)

ValueError: setting an array element with a sequence.

How to remove this error( I am a new user of python)?