bpo-36540: PEP 570 -- Implementation (GH-12701)

This commit contains the implementation of PEP570: Python positional-only parameters.

* Update Grammar/Grammar with new typedarglist and varargslist

* Regenerate grammar files

* Update and regenerate AST related files

* Update code object

* Update marshal.c

* Update compiler and symtable

* Regenerate importlib files

* Update callable objects

* Implement positional-only args logic in ceval.c

* Regenerate frozen data

* Update standard library to account for positional-only args

* Add test file for positional-only args

* Update other test files to account for positional-only args

* Add News entry

* Update inspect module and related tests

1 files changed, 6 insertions, 2 deletions

diff --git a/Tools/parser/unparse.py b/Tools/parser/unparse.py
index 70b47a1..385902e 100644
--- a/Tools/parser/unparse.py
+++ b/Tools/parser/unparse.py
@@ -592,14 +592,18 @@ class Unparser:
     def _arguments(self, t):
         first = True
         # normal arguments
-        defaults = [None] * (len(t.args) - len(t.defaults)) + t.defaults
-        for a, d in zip(t.args, defaults):
+        all_args = t.posonlyargs + t.args
+        defaults = [None] * (len(all_args) - len(t.defaults)) + t.defaults
+        for index, elements in enumerate(zip(all_args, defaults), 1):
+            a, d = elements
             if first:first = False
             else: self.write(", ")
             self.dispatch(a)
             if d:
                 self.write("=")
                 self.dispatch(d)
+            if index == len(t.posonlyargs):
+                self.write(", /")
 
         # varargs, or bare '*' if no varargs but keyword-only arguments present
         if t.vararg or t.kwonlyargs: