allow keyword args to be passed in after *args #3473

diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst
index 867074a28264809cbd2f1b8ca92c1bbedfe3a64b..1566a99a23a3124b10ca5c7a1eacfe825daed890 100644 (file)
--- a/Doc/reference/expressions.rst
+++ b/Doc/reference/expressions.rst
@@ -625,11 +625,11 @@ of arguments:
    call: `primary` "(" [`argument_list` [","]
        : | `expression` `genexpr_for`] ")"
    argument_list: `positional_arguments` ["," `keyword_arguments`]
-                : ["," "*" `expression`]
-                : ["," "**" `expression`]
+                :   ["," "*" `expression`] ["," `keyword_arguments`]
+                :   ["," "**" `expression`]
                 : | `keyword_arguments` ["," "*" `expression`]
-                : ["," "**" `expression`]
-                : | "*" `expression` ["," "**" `expression`]
+                :   ["," "**" `expression`]
+                : | "*" `expression` ["," "*" `expression`] ["," "**" `expression`]
                 : | "**" `expression`
    positional_arguments: `expression` ("," `expression`)*
    keyword_arguments: `keyword_item` ("," `keyword_item`)*
@@ -686,12 +686,13 @@ there were no excess keyword arguments.
 
 If the syntax ``*expression`` appears in the function call, ``expression`` must
 evaluate to a sequence.  Elements from this sequence are treated as if they were
-additional positional arguments; if there are positional arguments *x1*,...,*xN*
-, and ``expression`` evaluates to a sequence *y1*,...,*yM*, this is equivalent
-to a call with M+N positional arguments *x1*,...,*xN*,*y1*,...,*yM*.
+additional positional arguments; if there are positional arguments *x1*,...,
+*xN*, and ``expression`` evaluates to a sequence *y1*, ..., *yM*, this is
+equivalent to a call with M+N positional arguments *x1*, ..., *xN*, *y1*, ...,
+*yM*.
 
-A consequence of this is that although the ``*expression`` syntax appears
-*after* any keyword arguments, it is processed *before* the keyword arguments
+A consequence of this is that although the ``*expression`` syntax may appear
+*after* some keyword arguments, it is processed *before* the keyword arguments
 (and the ``**expression`` argument, if any -- see below).  So::
 
    >>> def f(a, b):

diff --git a/Grammar/Grammar b/Grammar/Grammar
index b014c72e8dfa3615e4147b7f4b967c9d3be6dde8..865d44c19d1ffd8bfa901138e4998dee3fe0c24c 100644 (file)
--- a/Grammar/Grammar
+++ b/Grammar/Grammar
@@ -130,7 +130,9 @@ dictmaker: test ':' test (',' test ':' test)* [',']
 
 classdef: 'class' NAME ['(' [testlist] ')'] ':' suite
 
-arglist: (argument ',')* (argument [',']| '*' test [',' '**' test] | '**' test)
+arglist: (argument ',')* (argument [',']
+                         |'*' test (',' argument)* [',' '**' test] 
+                         |'**' test)
 argument: test [gen_for] | test '=' test  # Really [keyword '='] test
 
 list_iter: list_for | list_if

diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py
index e749e440ca159df0bc7b963f9b64c3f878bea033..f8cef6ac94fd6697d8f0bf94066ea8d5f8270966 100644 (file)
--- a/Lib/test/test_grammar.py
+++ b/Lib/test/test_grammar.py
@@ -282,6 +282,14 @@ class GrammarTests(unittest.TestCase):
         def d32v((x,)): pass
         d32v((1,))
 
+        # keyword arguments after *arglist
+        def f(*args, **kwargs):
+            return args, kwargs
+        self.assertEquals(f(1, x=2, *[3, 4], y=5), ((1, 3, 4),
+                                                    {'x':2, 'y':5}))
+        self.assertRaises(SyntaxError, eval, "f(1, *(2,3), 4)")
+        self.assertRaises(SyntaxError, eval, "f(1, x=2, *(3,4), x=5)")
+
         # Check ast errors in *args and *kwargs
         check_syntax_error(self, "f(*g(1=2))")
         check_syntax_error(self, "f(**g(1=2))")

diff --git a/Python/ast.c b/Python/ast.c
index b6a5e0f546f4881b1513a18a59b40825482c3209..8414c7448081832f8431f87c78b4b487b635501f 100644 (file)
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -1898,6 +1898,11 @@ ast_for_call(struct compiling *c, const node *n, expr_ty func)
                               "non-keyword arg after keyword arg");
                     return NULL;
                 }
+                if (vararg) {
+                    ast_error(CHILD(ch, 0),
+                              "only named arguments may follow *expression");
+                    return NULL;
+                }
                 e = ast_for_expr(c, CHILD(ch, 0));
                 if (!e)
                     return NULL;

diff --git a/Python/graminit.c b/Python/graminit.c
index 14a41d1b2ea948f6aab86300b93accf0b231ee14..e65a992a648585fc43a64985f0d73e27c6eee7bb 100644 (file)
--- a/Python/graminit.c
+++ b/Python/graminit.c
@@ -1609,7 +1609,8 @@ static arc arcs_74_5[2] = {
 static arc arcs_74_6[1] = {
        {0, 6},
 };
-static arc arcs_74_7[1] = {
+static arc arcs_74_7[2] = {
+       {162, 5},
        {31, 3},
 };
 static state states_74[8] = {
@@ -1620,7 +1621,7 @@ static state states_74[8] = {
        {4, arcs_74_4},
        {2, arcs_74_5},
        {1, arcs_74_6},
-       {1, arcs_74_7},
+       {2, arcs_74_7},
 };
 static arc arcs_75_0[1] = {
        {28, 1},