from sklearn import datasets
iris = datasets.load_iris()

X = iris.data
y = iris.target

from sklearn.cross_validation import train_test_split
X_train, X_test, y_train, y_test = train_test_split( X, y, test_size=.5 )

#from sklearn import tree
#my_classifier = tree.DecisionTreeClassifier()

from sklearn.neighbors import KNeighborsClassifier
my_classifier = KNeighborsClassifier()

my_classifier.fit( X_train, y_train )

predictions = my_classifier.predict( X_test )

from sklearn.metrics import accuracy_score
print accuracy_score( y_test, predictions )
