Not working code

[anakreonod]

Hello.
Why doesn't the code part work for the same logging data?
TypeErrorTraceback (most recent call last)
in ()
12 return labels[row['Lith_Section']-1]
13
---> 14 training_data.loc[:,'FaciesLabels'] = training_data.apply(lambda row: label_facies(row, facies_labels), axis=1)
15 training_data.describe()

5 frames
in label_facies(row, labels)
10
11 def label_facies(row, labels):
---> 12 return labels[row['Lith_Section']-1]
13
14 training_data.loc[:,'FaciesLabels'] = training_data.apply(lambda row: label_facies(row, facies_labels), axis=1)

TypeError: ('list indices must be integers, not float', u'occurred at index 0')

Thank you