title: Issue defining KneighborsClassifier in Jupyter Notebooks
body: <p>I am attempting to utilize KNN on the Iris data set as a "Hello World" of Machine Learning.  I am using a Jupyter Notebook from Anaconda and have been clearly documenting each step. A "NameError: name 'knn' is not defined" exception is currently being thrown when I attempt to use <code>knn.fit(X,Y)</code>  What am I missing here?  I attempted to test the definition of knn by calling <code>print(knn)</code> and I get the following output: </p>
  
  <pre><code>KNeighborsClassifier(algorithm='auto', leaf_size=30, metric='minkowski',
             metric_params=None, n_jobs=1, n_neighbors=1, p=2,
             weights='uniform')
  </code></pre>
  
  <p>Code below:</p>
  
  <pre><code>#import the load_iris dataset
  from sklearn.datasets import load_iris
  #save "bunch" object containing iris dataset and its attributes
  iris = load_iris()
  X = iris.data
  Y = iris.target
  
  #import class you plan to use
  from sklearn.neighbors import KNeighborsClassifier
  knn = KNeighborsClassifier(n_neighbors = 1)
  
  #Fit the model with data (aka "model training")
  knn.fit(X,Y)
  </code></pre>