title: ValueError: data type must provide an itemsize?
body: <p>My code as follows, every time when I run it , it has an error;</p>
  
  <p>"ValueError: data type must provide an itemsize"</p>
  
  <p>I can't find the reason why it doesn;t work.</p>
  
  <p>I don't know why?</p>
  
  <pre><code>from sklearn.linear_model import LogisticRegression
  trainX = [('2', '0.455', '0.365', '0.095', '0.514', '0.2245', '0.101', '0.15'), ('2', '0.35', '0.265', '0.09', '0.2255', '0.0995', '0.0485', '0.07'), ('1', '0.53', '0.42', '0.135', '0.677', '0.2565', '0.1415', '0.21'), ('2', '0.44', '0.365', '0.125', '0.516', '0.2155', '0.114', '0.155'), ('3', '0.33', '0.255', '0.08', '0.205', '0.0895', '0.0395', '0.055')]
  trainY = ['15', '7', '9', '10', '7']
  testX = [('3', '0.475', '0.36', '0.11', '0.452', '0.191', '0.099', '0.13'), ('3', '0.485', '0.37', '0.14', '0.5065', '0.2425', '0.088', '0.1465')]
  model = LogisticRegression()
  model.fit(trainX,trainY)
  predict = model.predict(testX[0:2])#error
  print predict
  </code></pre>