[Dy2Stat]Polish for zip in dy2stat (PaddlePaddle#37846)

* polish for zip in dy2stat

* polish comment

* polish is_builtin_len

* fix comment

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

@@ -39,18 +39,19 @@ def _no_need_convert_call(self, node):
         Determines whether a function needs to be transformed by `convert_call`.
         It doesn't need to be transformed when a function satisfies the following conditions:
           1. It's a api of paddle
-          2. It's a python builtin function not include `len`
+          2. It's a python builtin function not include `len` and `zip`
         """
         assert isinstance(node, gast.Call)
         if is_paddle_api(node):
             return True
 
         func_str = ast_to_source_code(node.func).strip()
         try:
-            from paddle.fluid.dygraph.dygraph_to_static.convert_call_func import is_builtin_len, is_builtin
+            from paddle.fluid.dygraph.dygraph_to_static.convert_call_func import is_builtin_len, is_builtin, is_builtin_zip
             is_builtin = eval("is_builtin({})".format(func_str))
             is_builtin_len = eval("is_builtin_len({})".format(func_str))
-            return is_builtin and not is_builtin_len
+            is_builtin_zip = eval("is_builtin_zip({})".format(func_str))
+            return is_builtin and not is_builtin_len and not is_builtin_zip
         except Exception:
             return False
 

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

@@ -27,7 +27,7 @@
 import six
 
 from paddle.fluid.dygraph.container import Sequential
-from paddle.fluid.dygraph.dygraph_to_static.convert_operators import convert_len
+from paddle.fluid.dygraph.dygraph_to_static.convert_operators import convert_len, convert_zip
 from paddle.fluid.dygraph.dygraph_to_static.logging_utils import TranslatorLogger
 from paddle.fluid.dygraph.dygraph_to_static.program_translator import StaticFunction
 from paddle.fluid.dygraph.dygraph_to_static.program_translator import convert_to_static
@@ -79,6 +79,10 @@ def is_builtin_len(func):
     return False
 
 
+def is_builtin_zip(func):
+    return is_builtin(func) and func.__name__ == 'zip'
+
+
 def is_unsupported(func):
     """
     Checks whether the func is supported by dygraph to static graph.
@@ -164,6 +168,9 @@ def dyfunc(x):
     if is_builtin_len(func):
         return convert_len
 
+    if is_builtin_zip(func):
+        return convert_zip
+
     if is_builtin(func) or is_unsupported(func):
         return func
 

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

@@ -298,6 +298,15 @@ def convert_len(var):
         return len(var)
 
 
+def convert_zip(*args):
+    for i, arg in enumerate(args):
+        if isinstance(arg, Variable) and arg.shape[0] == -1:
+            raise RuntimeError(
+                "Not support zip(tensor, ...) when tensor.shape[0] == -1, "
+                "but found args[{}].shape[0] == -1 in 'zip'".format(str(i)))
+    return zip(*args)
+
+
 def convert_var_shape(x, idx=None, in_control_flow=False):
     """
     A function representation of the shape of variable.

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

@@ -20,6 +20,7 @@
 import paddle
 import paddle.fluid as fluid
 from paddle.fluid.dygraph.dygraph_to_static import ProgramTranslator
+from paddle.static import InputSpec
 
 program_translator = ProgramTranslator()
 
@@ -322,6 +323,24 @@ def for_original_tuple():
     return z
 
 
+# 23. for zip error
+@paddle.jit.to_static(
+    input_spec=[InputSpec(shape=[None, 10]), InputSpec(shape=[None, 10])])
+def for_zip_error(x, y):
+    for i, j in zip(x, y):
+        a = i + j
+    return x + y
+
+
+# 24. for zip
+@paddle.jit.to_static(
+    input_spec=[InputSpec(shape=[2, 10]), InputSpec(shape=[2, 10])])
+def for_zip(x, y):
+    for i, j in zip(x, y):
+        a = i + j
+    return x + y
+
+
 class TestTransformBase(unittest.TestCase):
     def setUp(self):
         self.place = fluid.CUDAPlace(0) if fluid.is_compiled_with_cuda(
@@ -512,5 +531,14 @@ def test_transformed_result_compare(self):
         self.transformed_result_compare()
 
 
+class TestForZip(unittest.TestCase):
+    def test_for_zip_error(self):
+        with self.assertRaises(RuntimeError):
+            paddle.jit.save(for_zip_error, './for_zip_error')
+
+    def test_for_zip(self):
+        paddle.jit.save(for_zip, './for_zip')
+
+
 if __name__ == '__main__':
     unittest.main()