fix(imperative/python): add the default warning for args descending

GitOrigin-RevId: cb5f065e6ca7e3d18f39e95966316d0a2110d499

imperative/python/megengine/functional/math.py

@@ -22,6 +22,7 @@ from ..core.tensor import amp
 from ..core.tensor.utils import _normalize_axis, cast_tensors, setscalar, subgraph
 from ..jit import exclude_from_trace
 from ..tensor import Tensor
+from ..utils.deprecation import deprecated_kwargs_default
 from .debug_param import get_execution_strategy
 from .elemwise import clip, minimum
 from .tensor import broadcast_to, concat, expand_dims, squeeze
@@ -684,6 +685,7 @@ def sort(inp: Tensor, descending: bool = False) -> Tuple[Tensor, Tensor]:
     return tns, ind
 
 
+@deprecated_kwargs_default("1.12", "descending", 3)
 def topk(
     inp: Tensor,
     k: int,
@@ -712,7 +714,7 @@ def topk(
             import  megengine.functional as F
 
             x = tensor(np.array([2, 4, 6, 8, 7, 5, 3, 1], dtype=np.float32))
-            top, indices = F.topk(x, 5)
+            top, indices = F.topk(x, 5, descending=False)
             print(top.numpy(), indices.numpy())
 
         Outputs:

imperative/python/megengine/utils/deprecation.py

@@ -7,9 +7,12 @@
 # "AS IS" BASIS, WITHOUT ARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 import importlib
 import warnings
+from functools import wraps
 
 from deprecated.sphinx import deprecated
 
+warnings.filterwarnings(action="default", module="megengine")
+
 
 def deprecated_func(version, origin, name, tbd):
     r"""
@@ -27,16 +30,39 @@ def deprecated_func(version, origin, name, tbd):
         module = importlib.import_module(origin)
         func = module.__getattribute__(name)
         if should_warning:
-            with warnings.catch_warnings():
-                warnings.simplefilter(action="always")
+            warnings.warn(
+                "Call to deprecated function {}. (use {}.{} instead) -- Deprecated since version {}.".format(
+                    name, origin, name, version
+                ),
+                category=DeprecationWarning,
+                stacklevel=2,
+            )
+        return func(*args, **kwargs)
+
+    return wrapper
+
+
+def deprecated_kwargs_default(version, kwargs_name, kwargs_pos):
+    r"""
+    Args:
+        version: version to deprecate this default
+        kwargs_name: kwargs name
+        kwargs_pos: kwargs position
+    """
+
+    def deprecated(func):
+        @wraps(func)
+        def wrapper(*args, **kwargs):
+            if len(args) < kwargs_pos and kwargs_name not in kwargs:
                 warnings.warn(
-                    "Call to deprecated function {}. (use {}.{} instead) -- Deprecated since version {}.".format(
-                        name, origin, name, version
+                    "the default behavior for {} will be changed in version {}, please use it in keyword parameter way".format(
+                        kwargs_name, version
                     ),
-                    category=DeprecationWarning,
+                    category=PendingDeprecationWarning,
                     stacklevel=2,
                 )
-            should_warning = False
-        return func(*args, **kwargs)
+            return func(*args, **kwargs)
 
-    return wrapper
+        return wrapper
+
+    return deprecated