bow.py running error

[buaalyx]

Hello ，when I run bow.py I got this error in line 25 x_train = [each for each in zip(x_train, y_train) if each[0] != None]

ValueError: The truth value of an array with more than one element is ambiguous.Use a.any() or a.all()

Because each[0] here has more than one element and if I use each[0].any() or each[0].all() ，In the condition that each is None, It will get error also because None doesn't have the attribute any() or all()

Could you please tell me how can I solve this problem?Thanks a lot