SF patch #1438387, PEP 328: relative and absolute imports.

 - IMPORT_NAME takes an extra argument from the stack: the relativeness of
   the import. Only passed to __import__ when it's not -1.

 - __import__() takes an optional 5th argument for the same thing; it
   __defaults to -1 (old semantics: try relative, then absolute)

 - 'from . import name' imports name (be it module or regular attribute)
   from the current module's *package*. Likewise, 'from .module import name'
   will import name from a sibling to the current module.

 - Importing from outside a package is not allowed; 'from . import sys' in a
   toplevel module will not work, nor will 'from .. import sys' in a
   (single-level) package.

 - 'from __future__ import absolute_import' will turn on the new semantics
   for import and from-import: imports will be absolute, except for
   from-import with dots.

Includes tests for regular imports and importhooks, parser changes and a
NEWS item, but no compiler-package changes or documentation changes.

1 files changed, 3 insertions, 2 deletions

diff --git a/Include/Python-ast.h b/Include/Python-ast.h
index 3c5677c..7aef19b 100644
--- a/Include/Python-ast.h
+++ b/Include/Python-ast.h
@@ -159,6 +159,7 @@ struct _stmt {
                 struct {
                         identifier module;
                         asdl_seq *names;
+                        int level;
                 } ImportFrom;
                 
                 struct {
@@ -371,8 +372,8 @@ stmt_ty TryFinally(asdl_seq * body, asdl_seq * finalbody, int lineno, PyArena
                    *arena);
 stmt_ty Assert(expr_ty test, expr_ty msg, int lineno, PyArena *arena);
 stmt_ty Import(asdl_seq * names, int lineno, PyArena *arena);
-stmt_ty ImportFrom(identifier module, asdl_seq * names, int lineno, PyArena
-                   *arena);
+stmt_ty ImportFrom(identifier module, asdl_seq * names, int level, int lineno,
+                   PyArena *arena);
 stmt_ty Exec(expr_ty body, expr_ty globals, expr_ty locals, int lineno, PyArena
              *arena);
 stmt_ty Global(asdl_seq * names, int lineno, PyArena *arena);