[Dy2stat] Add Tuple as Assign Target for Tensor Shape (#28775)

Add support for using tuple as tensor.shape (For example: a, b, c, d = x.shape)

python/paddle/fluid/dygraph/dygraph_to_static/tensor_shape_transformer.py

@@ -17,6 +17,7 @@ from __future__ import print_function
 import copy
 import gast
 
+from paddle.fluid.dygraph.dygraph_to_static.utils import ast_to_source_code
 from paddle.fluid.dygraph.dygraph_to_static.utils import is_paddle_api
 from paddle.fluid.dygraph.dygraph_to_static.utils import SplitAssignTransformer
 from paddle.fluid.dygraph.dygraph_to_static.static_analysis import AstNodeWrapper
@@ -192,12 +193,39 @@ class TensorShapeTransformer(gast.NodeTransformer):
     def _update_name_to_var_shape(self, node):
         assert isinstance(node, gast.Assign)
         target_node = node.targets[0]
-        try:
-            target_id = target_node.id
-        except AttributeError:
-            return False
         value_node = node.value
 
+        if isinstance(target_node, gast.Tuple):
+            has_updated = False
+            for idx, element in enumerate(target_node.elts):
+                target_id = ast_to_source_code(element).strip()
+
+                if isinstance(value_node, gast.Name):
+                    if value_node.id in self.name_to_var_shape:
+                        index_value_node = gast.Constant(value=idx, kind=None)
+                        slice_index_node = gast.Index(value=index_value_node)
+                        var_shape_node = self.name_to_var_shape[value_node.id]
+                        sub_node = gast.Subscript(
+                            value=var_shape_node,
+                            slice=slice_index_node,
+                            ctx=gast.Load())
+                        self.name_to_var_shape[target_id] = sub_node
+                        has_updated = True
+                if isinstance(value_node, gast.Attribute):
+                    if self.is_var_shape(value_node):  # eg: x.shape
+                        index_value_node = gast.Constant(value=idx, kind=None)
+                        slice_index_node = gast.Index(value=index_value_node)
+                        sub_node = gast.Subscript(
+                            value=value_node,
+                            slice=slice_index_node,
+                            ctx=gast.Load())
+                        self.name_to_var_shape[target_id] = sub_node
+                        has_updated = True
+
+            return has_updated
+        else:
+            target_id = ast_to_source_code(target_node).strip()
+
             if isinstance(value_node, gast.Name):
                 if value_node.id in self.name_to_var_shape:
                     self.name_to_var_shape[target_id] = self.name_to_var_shape[

python/paddle/fluid/tests/unittests/dygraph_to_static/test_tensor_shape.py

@@ -17,6 +17,7 @@ from __future__ import print_function
 import numpy
 
 import unittest
+import paddle
 import paddle.fluid as fluid
 from paddle.fluid.dygraph.jit import declarative
 
@@ -59,6 +60,21 @@ def dyfunc_tensor_shape_5(x):
     return res
 
 
+def dyfunc_tuple_shape_1(x):
+    x = paddle.to_tensor(x)
+    a, b = x.shape
+    res = paddle.reshape(x, shape=(b, a))
+    return res
+
+
+def dyfunc_tuple_shape_2(x):
+    x = paddle.to_tensor(x)
+    shape = x.shape
+    a, b = shape
+    res = paddle.reshape(x, shape=(b, a))
+    return res
+
+
 def dyfunc_with_if_1(x):
     x = fluid.dygraph.to_variable(x)
     res = fluid.layers.reshape(x, [-1, 1])
@@ -224,6 +240,18 @@ class TestTensorShapeBasic5(TestTensorShapeBasic):
         self.dygraph_func = dyfunc_tensor_shape_5
 
 
+class TestTupleShape1(TestTensorShapeBasic):
+    def init_test_func(self):
+        self.input = numpy.ones((5, 7)).astype("int32")
+        self.dygraph_func = dyfunc_tuple_shape_1
+
+
+class TestTupleShape2(TestTensorShapeBasic):
+    def init_test_func(self):
+        self.input = numpy.ones((5, 7)).astype("int32")
+        self.dygraph_func = dyfunc_tuple_shape_2
+
+
 # 2. Tests with control flow if
 class TestTensorShapeInIf1(TestTensorShapeBasic):
     def init_test_func(self):