bpo-34890: Make iscoroutinefunction, isgeneratorfunction and isasyncgenfunction work with functools.partial

Lib/inspect.py

@@ -59,6 +59,11 @@
 # See Include/object.h
 TPFLAGS_IS_ABSTRACT = 1 << 20
 
+def _unwrap_partial(func):
+    while isinstance(func, functools.partial):
+        func = func.func
+    return func
+
 # ----------------------------------------------------------- type-checking
 def ismodule(object):
     """Return true if the object is a module.
@@ -168,30 +173,33 @@ def isfunction(object):
         __kwdefaults__  dict of keyword only parameters with defaults"""
     return isinstance(object, types.FunctionType)
 
-def isgeneratorfunction(object):
+def isgeneratorfunction(obj):
     """Return true if the object is a user-defined generator function.
 
     Generator function objects provide the same attributes as functions.
     See help(isfunction) for a list of attributes."""
-    return bool((isfunction(object) or ismethod(object)) and
-                object.__code__.co_flags & CO_GENERATOR)
+    obj = _unwrap_partial(obj)
+    return bool((isfunction(obj) or ismethod(obj)) and
+                obj.__code__.co_flags & CO_GENERATOR)
 
-def iscoroutinefunction(object):
+def iscoroutinefunction(obj):
     """Return true if the object is a coroutine function.
 
     Coroutine functions are defined with "async def" syntax.
     """
-    return bool((isfunction(object) or ismethod(object)) and
-                object.__code__.co_flags & CO_COROUTINE)
+    obj = _unwrap_partial(obj)
+    return bool(((isfunction(obj) or ismethod(obj)) and
+                obj.__code__.co_flags & CO_COROUTINE))
 
-def isasyncgenfunction(object):
+def isasyncgenfunction(obj):
     """Return true if the object is an asynchronous generator function.
 
     Asynchronous generator functions are defined with "async def"
     syntax and have "yield" expressions in their body.
     """
-    return bool((isfunction(object) or ismethod(object)) and
-                object.__code__.co_flags & CO_ASYNC_GENERATOR)
+    obj = _unwrap_partial(obj)
+    return bool((isfunction(obj) or ismethod(obj)) and
+                obj.__code__.co_flags & CO_ASYNC_GENERATOR)
 
 def isasyncgen(object):
     """Return true if the object is an asynchronous generator."""

Lib/test/test_inspect.py

@@ -166,26 +166,51 @@ def test_excluding_predicates(self):
             self.assertFalse(inspect.ismemberdescriptor(datetime.timedelta.days))
 
     def test_iscoroutine(self):
+        async_gen_coro = async_generator_function_example(1)
         gen_coro = gen_coroutine_function_example(1)
         coro = coroutine_function_example(1)
 
         self.assertFalse(
             inspect.iscoroutinefunction(gen_coroutine_function_example))
+        self.assertFalse(
+            inspect.iscoroutinefunction(
+                functools.partial(functools.partial(
+                    gen_coroutine_function_example))))
         self.assertFalse(inspect.iscoroutine(gen_coro))
 
         self.assertTrue(
             inspect.isgeneratorfunction(gen_coroutine_function_example))
+        self.assertTrue(
+            inspect.isgeneratorfunction(
+                functools.partial(functools.partial(
+                    gen_coroutine_function_example))))
         self.assertTrue(inspect.isgenerator(gen_coro))
 
         self.assertTrue(
             inspect.iscoroutinefunction(coroutine_function_example))
+        self.assertTrue(
+            inspect.iscoroutinefunction(
+                functools.partial(functools.partial(
+                    coroutine_function_example))))
         self.assertTrue(inspect.iscoroutine(coro))
 
         self.assertFalse(
             inspect.isgeneratorfunction(coroutine_function_example))
+        self.assertFalse(
+            inspect.isgeneratorfunction(
+                functools.partial(functools.partial(
+                    coroutine_function_example))))
         self.assertFalse(inspect.isgenerator(coro))
 
-        coro.close(); gen_coro.close() # silence warnings
+        self.assertTrue(
+            inspect.isasyncgenfunction(async_generator_function_example))
+        self.assertTrue(
+            inspect.isasyncgenfunction(
+                functools.partial(functools.partial(
+                    async_generator_function_example))))
+        self.assertTrue(inspect.isasyncgen(async_gen_coro))
+
+        coro.close(); gen_coro.close(); # silence warnings
 
     def test_isawaitable(self):
         def gen(): yield

Misc/NEWS.d/next/Library/2018-10-15-23-10-41.bpo-34890.77E770.rst

@@ -0,0 +1,3 @@
+Make :func:`inspect.iscoroutinefunction`,
+:func:`inspect.isgeneratorfunction` and :func:`inspect.isasyncgenfunction`
+work with :func:`functools.partial`. Patch by Pablo Galindo.