Python 3.x Pybrain:'；监控数据集'；对象没有属性'_convertToOneOfMany'；

我正在努力理解pybrain文档。有一个分类演示

from pybrain.datasets            import ClassificationDataSet
from pybrain.utilities           import percentError
from pybrain.tools.shortcuts     import buildNetwork
from pybrain.supervised.trainers import BackpropTrainer
from pybrain.structure.modules   import SoftmaxLayer

from pylab import ion, ioff, figure, draw, contourf, clf, show, 
hold, plot
from scipy import diag, arange, meshgrid, where
from numpy.random import multivariate_normal

means = [(-1,0),(2,4),(3,1)]
cov = [diag([1,1]), diag([0.5,1.2]), diag([1.5,0.7])]
alldata = ClassificationDataSet(2, 1, nb_classes=3)
for n in range(400):
    for klass in range(3):
        input = multivariate_normal(means[klass],cov[klass])
        alldata.addSample(input, [klass])


alldata._convertToOneOfMany()
tstdata, trndata = alldata.splitWithProportion( 0.25 )

trndata._convertToOneOfMany( )
tstdata._convertToOneOfMany( )

print("Number of training patterns: ", len(trndata))
print("Input and output dimensions: ", trndata.indim, trndata.outdim)
print("First sample (input, target, class):")
print(trndata['input'][0], trndata['target'][0], 
trndata['class'][0])

fnn = buildNetwork( trndata.indim, 5, trndata.outdim, 
outclass=SoftmaxLayer )

trainer = BackpropTrainer( fnn, dataset=trndata, momentum=0.1, 
verbose=True, weightdecay=0.01)

错误消息显示trnda和tstdata没有属性“\u convertToOneOfMany”。有人知道如何解决这个问题吗

谢谢