inspect: Support generators/async functions in inspect.signature.

Signed-off-by: Damien George <damien@micropython.org>

Author: dpgeorge

python-stdlib/inspect/inspect.py

@@ -111,7 +111,7 @@ def signature(f):
     elif t is type(setattr):
         # A three-parameter built-in.
         num_args = 3
-    elif t is type(signature):
+    elif t is type(signature) or t is type(_g):
         # A bytecode function, work out the number of arguments by inspecting the bytecode data.
         fun_obj = uctypes.struct(id(f), (uctypes.ARRAY | 0, uctypes.LONG | 4))
         bytecode = uctypes.bytearray_at(fun_obj[3], 8)

python-stdlib/inspect/manifest.py

@@ -1,3 +1,3 @@
-metadata(version="0.2.0")
+metadata(version="0.2.1")
 
 module("inspect.py")

python-stdlib/inspect/test_inspect.py

@@ -71,3 +71,4 @@ def test_signature(self):
         self.assertEqual(len(inspect.signature(lambda x, y: 0).parameters), 2)
         self.assertEqual(len(inspect.signature(lambda x, y, z: 0).parameters), 3)
         self.assertEqual(len(inspect.signature(lambda x, y, *, z: 0).parameters), 3)
+        self.assertEqual(len(inspect.signature(gen).parameters), 0)