HybridBlock.export() to return created filenames (#17758)

* [Gluon] Return filenames from HybridBlock.export (#1579)

* [Gluon] Unittest filenames from HybridBlock.export (#1579)

* [Gluon] Perl HybridBlock.export return filenames (#1579)

* [Gluon] HybridBlock.export docstring grammar fix

* Linting - fix trailing whitespace

perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Block.pm

@@ -1254,7 +1254,8 @@ method export(Str $path, :$epoch=0)
         );
     }
     my $sym = $self->_cached_graph->[1];
-    $sym->save("$path-symbol.json");
+    my $sym_filename = "$path-symbol.json";
+    $sym->save($sym_filename);
 
     my %arg_names = map { $_ => 1 } @{ $sym->list_arguments };
     my %aux_names = map { $_ => 1 } @{ $sym->list_auxiliary_states };
@@ -1273,7 +1274,9 @@ method export(Str $path, :$epoch=0)
             $arg_dict{ "aux:$name" } = $param->_reduce;
         }
     }
-    AI::MXNet::NDArray->save(sprintf('%s-%04d.params', $path, $epoch), \%arg_dict);
+    my $params_filename = sprintf('%s-%04d.params', $path, $epoch);
+    AI::MXNet::NDArray->save($params_filename, \%arg_dict);
+    return ($sym_filename, $params_filename);
 }
 
 __PACKAGE__->register('AI::MXNet::Gluon');

python/mxnet/gluon/block.py

@@ -1133,13 +1133,21 @@ def export(self, path, epoch=0, remove_amp_cast=True):
             will be created, where xxxx is the 4 digits epoch number.
         epoch : int
             Epoch number of saved model.
+
+        Returns
+        -------
+        symbol_filename : str
+            Filename to which model symbols were saved, including `path` prefix.
+        params_filename : str
+            Filename to which model parameters were saved, including `path` prefix.
         """
         if not self._cached_graph:
             raise RuntimeError(
                 "Please first call block.hybridize() and then run forward with "
                 "this block at least once before calling export.")
         sym = self._cached_graph[1]
-        sym.save('%s-symbol.json'%path, remove_amp_cast=remove_amp_cast)
+        sym_filename = '%s-symbol.json'%path
+        sym.save(sym_filename, remove_amp_cast=remove_amp_cast)
 
         arg_names = set(sym.list_arguments())
         aux_names = set(sym.list_auxiliary_states())
@@ -1151,7 +1159,9 @@ def export(self, path, epoch=0, remove_amp_cast=True):
                 assert name in aux_names
                 arg_dict['aux:%s'%name] = param._reduce()
         save_fn = _mx_npx.save if is_np_array() else ndarray.save
-        save_fn('%s-%04d.params'%(path, epoch), arg_dict)
+        params_filename = '%s-%04d.params'%(path, epoch)
+        save_fn(params_filename, arg_dict)
+        return (sym_filename, params_filename)
 
     def register_op_hook(self, callback, monitor_all=False):
         """Install op hook for block recursively.

tests/python/unittest/test_gluon.py

@@ -1191,7 +1191,9 @@ def test_export():
     data = mx.nd.random.normal(shape=(1, 3, 32, 32))
     out = model(data)
 
-    model.export('gluon')
+    symbol_filename, params_filename = model.export('gluon')
+    assert symbol_filename == 'gluon-symbol.json'
+    assert params_filename == 'gluon-0000.params'
 
     module = mx.mod.Module.load('gluon', 0, label_names=None, context=ctx)
     module.bind(data_shapes=[('data', data.shape)])