[eager Tensor] Update type hint for Tensor.__format__ and add unittest (#68694)

HydrogenSulfate · web-flow · commit fbc6cf3a7a35 · 2024-10-15T10:11:22.000+08:00
diff --git a/python/paddle/base/dygraph/tensor_patch_methods.py b/python/paddle/base/dygraph/tensor_patch_methods.py
@@ -913,7 +913,7 @@ def __str__(self: Tensor) -> str:
 
         return tensor_to_string(self)
 
-    def __format__(self, format_spec):
+    def __format__(self, format_spec: str) -> str:
         if self.ndim == 0:
             return self.item().__format__(format_spec)
 
diff --git a/test/legacy_test/test_eager_tensor.py b/test/legacy_test/test_eager_tensor.py
@@ -1301,6 +1301,12 @@ def test_tensor__format__(self):
                 numpy_scalar.__format__(format_spec),
             )
 
+            format_spec = "{:.{}f}"
+            self.assertEqual(
+                format_spec.format(paddle_scalar, width),
+                format_spec.format(numpy_scalar, width),
+            )
+
         # test for integer scalar
         for width in range(0, 5):
             paddle_scalar = paddle.uniform([], min=-100, max=100).to("int64")
@@ -1321,6 +1327,12 @@ def test_tensor__format__(self):
                 numpy_scalar.__format__(format_spec),
             )
 
+            format_spec = "{:{}d}"
+            self.assertEqual(
+                format_spec.format(paddle_scalar, width),
+                format_spec.format(numpy_scalar, width),
+            )
+
         # test for tensor that ndim > 0, expected to raise TypeError
         paddle_scalar = paddle.uniform([1], min=-100, max=100)
         self.assertRaises(TypeError, paddle_scalar.__format__, ".3f")
