text: import unittest
  import tempfile
  import os
  import six
  
  import caffe
  
  
  class SimpleLayer(caffe.Layer):
      """A layer that just multiplies by ten"""
  
      def setup(self, bottom, top):
          pass
  
      def reshape(self, bottom, top):
          top[0].reshape(*bottom[0].data.shape)
  
      def forward(self, bottom, top):
          top[0].data[...] = 10 * bottom[0].data
  
      def backward(self, top, propagate_down, bottom):
          bottom[0].diff[...] = 10 * top[0].diff
  
  
  class ExceptionLayer(caffe.Layer):
      """A layer for checking exceptions from Python"""
  
      def setup(self, bottom, top):
          raise RuntimeError
  
  class ParameterLayer(caffe.Layer):
      """A layer that just multiplies by ten"""
  
      def setup(self, bottom, top):
          self.blobs.add_blob(1)
          self.blobs[0].data[0] = 0
  
      def reshape(self, bottom, top):
          top[0].reshape(*bottom[0].data.shape)
  
      def forward(self, bottom, top):
          pass
  
      def backward(self, top, propagate_down, bottom):
          self.blobs[0].diff[0] = 1
  
  def python_net_file():
      with tempfile.NamedTemporaryFile(mode='w+', delete=False) as f:
          f.write("""name: 'pythonnet' force_backward: true
          input: 'data' input_shape { dim: 10 dim: 9 dim: 8 }
          layer { type: 'Python' name: 'one' bottom: 'data' top: 'one'
            python_param { module: 'test_python_layer' layer: 'SimpleLayer' } }
          layer { type: 'Python' name: 'two' bottom: 'one' top: 'two'
            python_param { module: 'test_python_layer' layer: 'SimpleLayer' } }
          layer { type: 'Python' name: 'three' bottom: 'two' top: 'three'
            python_param { module: 'test_python_layer' layer: 'SimpleLayer' } }""")
          return f.name
  
  
  def exception_net_file():
      with tempfile.NamedTemporaryFile(mode='w+', delete=False) as f:
          f.write("""name: 'pythonnet' force_backward: true
          input: 'data' input_shape { dim: 10 dim: 9 dim: 8 }
          layer { type: 'Python' name: 'layer' bottom: 'data' top: 'top'
            python_param { module: 'test_python_layer' layer: 'ExceptionLayer' } }
            """)
          return f.name
  
  
  def parameter_net_file():
      with tempfile.NamedTemporaryFile(mode='w+', delete=False) as f:
          f.write("""name: 'pythonnet' force_backward: true
          input: 'data' input_shape { dim: 10 dim: 9 dim: 8 }
          layer { type: 'Python' name: 'layer' bottom: 'data' top: 'top'
            python_param { module: 'test_python_layer' layer: 'ParameterLayer' } }
            """)
          return f.name
  
  
  @unittest.skipIf('Python' not in caffe.layer_type_list(),
      'Caffe built without Python layer support')
  class TestPythonLayer(unittest.TestCase):
      def setUp(self):
          net_file = python_net_file()
          self.net = caffe.Net(net_file, caffe.TRAIN)
          os.remove(net_file)
  
      def test_forward(self):
          x = 8
          self.net.blobs['data'].data[...] = x
          self.net.forward()
          for y in self.net.blobs['three'].data.flat:
              self.assertEqual(y, 10**3 * x)
  
      def test_backward(self):
          x = 7
          self.net.blobs['three'].diff[...] = x
          self.net.backward()
          for y in self.net.blobs['data'].diff.flat:
              self.assertEqual(y, 10**3 * x)
  
      def test_reshape(self):
          s = 4
          self.net.blobs['data'].reshape(s, s, s, s)
          self.net.forward()
          for blob in six.itervalues(self.net.blobs):
              for d in blob.data.shape:
                  self.assertEqual(s, d)
  
      def test_exception(self):
          net_file = exception_net_file()
          self.assertRaises(RuntimeError, caffe.Net, net_file, caffe.TEST)
          os.remove(net_file)
  
      def test_parameter(self):
          net_file = parameter_net_file()
          net = caffe.Net(net_file, caffe.TRAIN)
          # Test forward and backward
          net.forward()
          net.backward()
          layer = net.layers[list(net._layer_names).index('layer')]
          self.assertEqual(layer.blobs[0].data[0], 0)
          self.assertEqual(layer.blobs[0].diff[0], 1)
          layer.blobs[0].data[0] += layer.blobs[0].diff[0]
          self.assertEqual(layer.blobs[0].data[0], 1)
  
          # Test saving and loading
          h, caffemodel_file = tempfile.mkstemp()
          net.save(caffemodel_file)
          layer.blobs[0].data[0] = -1
          self.assertEqual(layer.blobs[0].data[0], -1)
          net.copy_from(caffemodel_file)
          self.assertEqual(layer.blobs[0].data[0], 1)
          if os.name == 'nt':
          # On Windows, attempting to remove a file that is in use
          # causes an exception to be raised."
            os.close(h)
          os.remove(caffemodel_file)
          
          # Test weight sharing
          net2 = caffe.Net(net_file, caffe.TRAIN)
          net2.share_with(net)
          layer = net.layers[list(net2._layer_names).index('layer')]
          self.assertEqual(layer.blobs[0].data[0], 1)
  
          os.remove(net_file)
  