Move 2.7 to 2 (#635)

Closes #579.

stdlib/2/ast.pyi

@@ -0,0 +1,45 @@
+# Python 2.7 ast
+
+import typing
+from typing import Any, Iterator, Union
+
+from _ast import (
+    Add, alias, And, arguments, Assert, Assign, AST, Attribute, AugAssign,
+    AugLoad, AugStore, BinOp, BitAnd, BitOr, BitXor, BoolOp, boolop, Break,
+    Call, ClassDef, cmpop, Compare, comprehension, Continue, Del, Delete, Dict,
+    DictComp, Div, Ellipsis, Eq, ExceptHandler, Exec, Expr, expr, Expression,
+    expr_context, ExtSlice, FloorDiv, For, FunctionDef, GeneratorExp, Global,
+    Gt, GtE, If, IfExp, Import, ImportFrom, In, Index, Interactive, Invert, Is,
+    IsNot, keyword, Lambda, List, ListComp, Load, LShift, Lt, LtE, Mod, mod,
+    Module, Mult, Name, Not, NotEq, NotIn, Num, operator, Or, Param, Pass, Pow,
+    Print, Raise, Repr, Return, RShift, Set, SetComp, Slice, slice, stmt,
+    Store, Str, Sub, Subscript, Suite, TryExcept, TryFinally, Tuple, UAdd,
+    UnaryOp, unaryop, USub, While, With, Yield
+)
+
+__version__ = ...  # type: str
+PyCF_ONLY_AST = ...  # type: int
+
+
+def parse(source: Union[str, bytes], filename: Union[str, bytes] = ..., mode: str = ...) -> AST: ...
+def copy_location(new_node: AST, old_node: AST) -> AST: ...
+def dump(node: AST, annotate_fields: bool = ..., include_attributes: bool = ...) -> str: ...
+def fix_missing_locations(node: AST) -> AST: ...
+def get_docstring(node: AST, clean: bool = ...) -> str: ...
+def increment_lineno(node: AST, n: int = ...) -> AST: ...
+def iter_child_nodes(node: AST) -> Iterator[AST]: ...
+def iter_fields(node: AST) -> Iterator[typing.Tuple[str, Any]]: ...
+def literal_eval(node_or_string: Union[str, AST]) -> Any: ...
+def walk(node: AST) -> Iterator[AST]: ...
+
+class NodeVisitor():
+    __doc__ = ...  # type: str
+    def visit(self, node: AST) -> Any: ...
+    def generic_visit(self, node: AST) -> None: ...
+
+class NodeTransformer(NodeVisitor):
+    __doc__ = ...  # type: str
+    def generic_visit(self, node: AST) -> None: ...
+
+
+