use inspect.signature instead of getcallargs. also improve argscope with this

tensorpack/models/common.py

@@ -3,6 +3,7 @@
 # Author: Yuxin Wu <ppwwyyxx@gmail.com>
 
 import tensorflow as tf
+import inspect
 from functools import wraps
 import six
 import re
@@ -14,7 +15,7 @@ from ..utils import logger
 
 # make sure each layer is only logged once
 _LAYER_LOGGED = set()
-_LAYER_REGISTERED = {}
+_LAYER_REGISTRY = {}
 
 __all__ = ['layer_register']
 
@@ -53,11 +54,11 @@ class VariableHolder(object):
 
 
 def _register(name, func):
-    if name in _LAYER_REGISTERED:
+    if name in _LAYER_REGISTRY:
         raise ValueError("Layer named {} is already registered!".format(name))
     if name in ['tf']:
         raise ValueError(logger.error("A layer cannot be named {}".format(name)))
-    _LAYER_REGISTERED[name] = func
+    _LAYER_REGISTRY[name] = func
 
 
 def get_registered_layer(name):
@@ -67,7 +68,7 @@ def get_registered_layer(name):
     Returns:
         the wrapped layer function, or None if not registered.
     """
-    return _LAYER_REGISTERED.get(name, None)
+    return _LAYER_REGISTRY.get(name, None)
 
 
 def disable_layer_logging():
@@ -124,10 +125,18 @@ def layer_register(
                         isinstance(inputs[0], (tf.Tensor, tf.Variable)))):
                 raise ValueError("Invalid inputs to layer: " + str(inputs))
 
-            # TODO use inspect.getcallargs to enhance?
-            # update from current argument scope
+            # use kwargs from current argument scope
             actual_args = copy.copy(get_arg_scope()[func.__name__])
+            # explicit kwargs overwrite argscope
             actual_args.update(kwargs)
+            # explicit positional args also override argscope
+            if six.PY2:
+                posargmap = inspect.getcallargs(func, *args)
+            else:
+                posargmap = inspect.signature(func).bind_partial(*args).arguments
+            for k in six.iterkeys(posargmap):
+                if k in actual_args:
+                    del actual_args[k]
 
             if name is not None:        # use scope
                 with tf.variable_scope(name) as scope:

tensorpack/utils/argtools.py

@@ -20,12 +20,17 @@ def map_arg(**maps):
     Apply a mapping on certains argument before calling the original function.
 
     Args:
-        maps (dict): {key: map_func}
+        maps (dict): {argument_name: map_func}
     """
     def deco(func):
         @functools.wraps(func)
         def wrapper(*args, **kwargs):
-            argmap = inspect.getcallargs(func, *args, **kwargs)
+            if six.PY2:
+                argmap = inspect.getcallargs(func, *args, **kwargs)
+            else:
+                # getcallargs was deprecated since 3.5
+                sig = inspect.signature(func)
+                argmap = sig.bind_partial(*args, **kwargs).arguments
             for k, map_func in six.iteritems(maps):
                 if k in argmap:
                     argmap[k] = map_func(argmap[k])