Fixed an issue where using partial on a generator function in python 3.5 was raising a SyntaxError. Fixed #79

Author: Sylvain MARIE

src/makefun/_main_latest_py.py src/makefun/_main_py35_and_higher.pysrc/makefun/_main_latest_py.py renamed to src/makefun/_main_py35_and_higher.py

@@ -22,22 +22,3 @@ def partial_f(*args, **kwargs):
         kwargs.update(preset_kwargs)  # for python 3.4: explicit dict update
         yield from f(*chain(preset_pos_args, args), **kwargs)
     return partial_f
-
-
-def make_partial_using_async_for_in_yield(new_sig, f, *preset_pos_args, **preset_kwargs):
-    """
-    Makes a 'partial' when f is a async generator and python is new enough to support `async for v in f(): yield v`
-
-    :param new_sig:
-    :param f:
-    :param presets:
-    :return:
-    """
-
-    @wraps(f, new_sig=new_sig)
-    async def partial_f(*args, **kwargs):
-        kwargs.update(preset_kwargs)
-        async for v in f(*chain(preset_pos_args, args), **kwargs):
-            yield v
-
-    return partial_f

src/makefun/_main_py36_and_higher.py

@@ -0,0 +1,26 @@
+# Authors: Sylvain MARIE <[email protected]>
+#          + All contributors to <https://github.com/smarie/python-makefun>
+#
+# License: 3-clause BSD, <https://github.com/smarie/python-makefun/blob/master/LICENSE>
+from itertools import chain
+
+from makefun.main import wraps
+
+
+def make_partial_using_async_for_in_yield(new_sig, f, *preset_pos_args, **preset_kwargs):
+    """
+    Makes a 'partial' when f is a async generator and python is new enough to support `async for v in f(): yield v`
+
+    :param new_sig:
+    :param f:
+    :param presets:
+    :return:
+    """
+
+    @wraps(f, new_sig=new_sig)
+    async def partial_f(*args, **kwargs):
+        kwargs.update(preset_kwargs)
+        async for v in f(*chain(preset_pos_args, args), **kwargs):
+            yield v
+
+    return partial_f

src/makefun/main.py

@@ -1127,13 +1127,13 @@ def partial(f,                 # type: Callable
 
     if _is_generator_func(f):
         if sys.version_info >= (3, 3):
-            from makefun._main_latest_py import make_partial_using_yield_from
+            from makefun._main_py35_and_higher import make_partial_using_yield_from
             partial_f = make_partial_using_yield_from(new_sig, f, *preset_pos_args, **preset_kwargs)
         else:
             from makefun._main_legacy_py import make_partial_using_yield
             partial_f = make_partial_using_yield(new_sig, f, *preset_pos_args, **preset_kwargs)
     elif isasyncgenfunction(f) and sys.version_info >= (3, 6):
-        from makefun._main_latest_py import make_partial_using_async_for_in_yield
+        from makefun._main_py36_and_higher import make_partial_using_async_for_in_yield
         partial_f = make_partial_using_async_for_in_yield(new_sig, f, *preset_pos_args, **preset_kwargs)
     else:
         @wraps(f, new_sig=new_sig)

tests/test_partial_and_macros.py

@@ -174,10 +174,19 @@ def f(a, b, c, **d):
         # assert str(signature(fp_ref)) == str(signature(fp))
 
 
-def test_simple_partial_copy():
-    """Test that when not providing any argument to partial, it is equivalent to wraps with new sig = None"""
-    def f1(a):
-        return a + 1
+@pytest.mark.parametrize("is_generator", [False, True])
+def test_simple_partial_copy(is_generator):
+    """Test that when not providing any argument to partial, it is equivalent to wraps with new sig = None
+
+    This test was extended to cover issue 79.
+    """
+
+    if is_generator:
+        def f1(a):
+            yield a + 1
+    else:
+        def f1(a):
+            return a + 1
 
     f2 = makefun.partial(f1)
 
@@ -188,7 +197,10 @@ def f1(a):
     f3 = makefun.wraps(f1)(f1)
     assert f3.__wrapped__ == f1
 
-    assert f2(1) == f3(1) == 2
+    if is_generator:
+        assert next(f2(1)) == next(f3(1)) == 2
+    else:
+        assert f2(1) == f3(1) == 2
 
     # the func attribute is there too
     f4 = functools.partial(f1)