# Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
# For details: https://github.com/PyCQA/astroid/blob/main/LICENSE
# Copyright (c) https://github.com/PyCQA/astroid/blob/main/CONTRIBUTORS.txt
"""This module contains some base nodes that can be inherited for the different nodes.
Previously these were called Mixin nodes.
"""
from __future__ import annotations
import itertools
import sys
from collections.abc import Iterator
from typing import TYPE_CHECKING, ClassVar
from astroid import decorators
from astroid.exceptions import AttributeInferenceError
from astroid.nodes.node_ng import NodeNG
if TYPE_CHECKING:
from astroid import nodes
if sys.version_info >= (3, 8):
from functools import cached_property
else:
from astroid.decorators import cachedproperty as cached_property
[docs]class Statement(NodeNG):
"""Statement node adding a few attributes
NOTE: This class is part of the public API of 'astroid.nodes'.
"""
is_statement = True
"""Whether this node indicates a statement."""
[docs] def next_sibling(self):
"""The next sibling statement node.
:returns: The next sibling statement node.
:rtype: NodeNG or None
"""
stmts = self.parent.child_sequence(self)
index = stmts.index(self)
try:
return stmts[index + 1]
except IndexError:
return None
[docs] def previous_sibling(self):
"""The previous sibling statement.
:returns: The previous sibling statement node.
:rtype: NodeNG or None
"""
stmts = self.parent.child_sequence(self)
index = stmts.index(self)
if index >= 1:
return stmts[index - 1]
return None
class NoChildrenNode(NodeNG):
"""Base nodes for nodes with no children, e.g. Pass."""
def get_children(self) -> Iterator[NodeNG]:
yield from ()
class FilterStmtsBaseNode(NodeNG):
"""Base node for statement filtering and assignment type"""
def _get_filtered_stmts(self, _, node, _stmts, mystmt: Statement | None):
"""method used in _filter_stmts to get statements and trigger break"""
if self.statement(future=True) is mystmt:
# original node's statement is the assignment, only keep
# current node (gen exp, list comp)
return [node], True
return _stmts, False
def assign_type(self):
return self
class AssignTypeNode(NodeNG):
"""Base node for nodes that can 'assign' such as AnnAssign."""
def assign_type(self):
return self
def _get_filtered_stmts(self, lookup_node, node, _stmts, mystmt: Statement | None):
"""method used in filter_stmts"""
if self is mystmt:
return _stmts, True
if self.statement(future=True) is mystmt:
# original node's statement is the assignment, only keep
# current node (gen exp, list comp)
return [node], True
return _stmts, False
class ParentAssignNode(AssignTypeNode):
"""Base node for nodes whose assign_type is determined by the parent node."""
def assign_type(self):
return self.parent.assign_type()
class ImportNode(FilterStmtsBaseNode, NoChildrenNode, Statement):
"""Base node for From and Import Nodes"""
modname: str | None
"""The module that is being imported from.
This is ``None`` for relative imports.
"""
names: list[tuple[str, str | None]]
"""What is being imported from the module.
Each entry is a :class:`tuple` of the name being imported,
and the alias that the name is assigned to (if any).
"""
def _infer_name(self, frame, name):
return name
def do_import_module(self, modname: str | None = None) -> nodes.Module:
"""return the ast for a module whose name is <modname> imported by <self>"""
# handle special case where we are on a package node importing a module
# using the same name as the package, which may end in an infinite loop
# on relative imports
# XXX: no more needed ?
mymodule = self.root()
level = getattr(self, "level", None) # Import as no level
if modname is None:
modname = self.modname
# XXX we should investigate deeper if we really want to check
# importing itself: modname and mymodule.name be relative or absolute
# pylint: disable-next=no-member # pylint doesn't recognize type of mymodule
if mymodule.relative_to_absolute_name(modname, level) == mymodule.name:
# FIXME: we used to raise InferenceError here, but why ?
return mymodule
# pylint: disable-next=no-member # pylint doesn't recognize type of mymodule
return mymodule.import_module(
modname, level=level, relative_only=level and level >= 1
)
def real_name(self, asname):
"""get name from 'as' name"""
for name, _asname in self.names:
if name == "*":
return asname
if not _asname:
name = name.split(".", 1)[0]
_asname = name
if asname == _asname:
return name
raise AttributeInferenceError(
"Could not find original name for {attribute} in {target!r}",
target=self,
attribute=asname,
)
class MultiLineBlockNode(NodeNG):
"""Base node for multi-line blocks, e.g. For and FunctionDef.
Note that this does not apply to every node with a `body` field.
For instance, an If node has a multi-line body, but the body of an
IfExpr is not multi-line, and hence cannot contain Return nodes,
Assign nodes, etc.
"""
_multi_line_block_fields: ClassVar[tuple[str, ...]] = ()
@cached_property
def _multi_line_blocks(self):
return tuple(getattr(self, field) for field in self._multi_line_block_fields)
def _get_return_nodes_skip_functions(self):
for block in self._multi_line_blocks:
for child_node in block:
if child_node.is_function:
continue
yield from child_node._get_return_nodes_skip_functions()
def _get_yield_nodes_skip_lambdas(self):
for block in self._multi_line_blocks:
for child_node in block:
if child_node.is_lambda:
continue
yield from child_node._get_yield_nodes_skip_lambdas()
@decorators.cached
def _get_assign_nodes(self):
children_assign_nodes = (
child_node._get_assign_nodes()
for block in self._multi_line_blocks
for child_node in block
)
return list(itertools.chain.from_iterable(children_assign_nodes))
class MultiLineWithElseBlockNode(MultiLineBlockNode):
"""Base node for multi-line blocks that can have else statements."""
@cached_property
def blockstart_tolineno(self):
return self.lineno
def _elsed_block_range(self, lineno, orelse, last=None):
"""handle block line numbers range for try/finally, for, if and while
statements
"""
if lineno == self.fromlineno:
return lineno, lineno
if orelse:
if lineno >= orelse[0].fromlineno:
return lineno, orelse[-1].tolineno
return lineno, orelse[0].fromlineno - 1
return lineno, last or self.tolineno