Add repr for SymbolBlock

python/mxnet/gluon/block.py

@@ -1024,6 +1024,14 @@ def imports(symbol_file, input_names, param_file=None, ctx=None):
             ret.collect_params().load(param_file, ctx=ctx)
         return ret
 
+    def __repr__(self):
+        s = '{name}(\n{modstr}\n)'
+        modstr = '\n'.join(['{block} : {numinputs} -> {numoutputs}'.format(block=self._cached_graph[1],
+                                                                           numinputs=len(self._cached_graph[0]),
+                                                                           numoutputs=len(self._cached_graph[1].
+                                                                                          list_outputs()))])
+        return s.format(name=self.__class__.__name__,
+                        modstr=modstr)
 
     def __init__(self, outputs, inputs, params=None):
         super(SymbolBlock, self).__init__(prefix=None, params=None)

tests/python/unittest/test_gluon.py

@@ -882,8 +882,13 @@ def test_import():
     net2 = gluon.SymbolBlock.imports(
         'net1-symbol.json', ['data'], 'net1-0001.params', ctx)
     out2 = net2(data)
+    lines = str(net2).splitlines()
 
     assert_almost_equal(out1.asnumpy(), out2.asnumpy())
+    assert lines[0] == 'SymbolBlock('
+    assert lines[1]
+    assert lines[2] == ')'
+
 
 @with_seed()
 def test_hybrid_stale_cache():