commit 2085bd0877e17ad4d98a4586d5eabb6faecbb190
author Serhiy Storchaka <storchaka@gmail.com> Sat Jun 01 11:00:15 2019 +0300
committer GitHub <noreply@github.com> Sat Jun 01 11:00:15 2019 +0300
tree c25b20d33ebf4d64a28abb8591f4ff7acf90614c
parent 4a686504eb2bbf69adf78077458508a7ba131667

bpo-37116: Use PEP 570 syntax for positional-only parameters. (GH-13700)

Lib/functools.py

diff --git a/Lib/functools.py b/Lib/functools.py
index 30964a6..64d1201 100644
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -273,15 +273,9 @@
 
     __slots__ = "func", "args", "keywords", "__dict__", "__weakref__"
 
-    def __new__(*args, **keywords):
-        if not args:
-            raise TypeError("descriptor '__new__' of partial needs an argument")
-        if len(args) < 2:
-            raise TypeError("type 'partial' takes at least one argument")
-        cls, func, *args = args
+    def __new__(cls, func, /, *args, **keywords):
         if not callable(func):
             raise TypeError("the first argument must be callable")
-        args = tuple(args)
 
         if hasattr(func, "func"):
             args = func.args + args
@@ -295,10 +289,7 @@
         self.keywords = keywords
         return self
 
-    def __call__(*args, **keywords):
-        if not args:
-            raise TypeError("descriptor '__call__' of partial needs an argument")
-        self, *args = args
+    def __call__(self, /, *args, **keywords):
         keywords = {**self.keywords, **keywords}
         return self.func(*self.args, *args, **keywords)
 
@@ -402,8 +393,7 @@
                                     keywords=keywords)
 
     def _make_unbound_method(self):
-        def _method(*args, **keywords):
-            cls_or_self, *args = args
+        def _method(cls_or_self, /, *args, **keywords):
             keywords = {**self.keywords, **keywords}
             return self.func(cls_or_self, *self.args, *args, **keywords)
         _method.__isabstractmethod__ = self.__isabstractmethod__