Viewing file:  typing.py (19.91 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
# For details: https://github.com/PyCQA/pylint/blob/main/LICENSE
# Copyright (c) https://github.com/PyCQA/pylint/blob/main/CONTRIBUTORS.txt
from __future__ import annotations
from typing import TYPE_CHECKING, NamedTuple
import astroid.bases
from astroid import nodes
from pylint.checkers import BaseChecker
from pylint.checkers.utils import (
in_type_checking_block,
is_node_in_type_annotation_context,
is_postponed_evaluation_enabled,
only_required_for_messages,
safe_infer,
)
from pylint.constants import TYPING_NORETURN
from pylint.interfaces import HIGH, INFERENCE
if TYPE_CHECKING:
from pylint.lint import PyLinter
class TypingAlias(NamedTuple):
name: str
name_collision: bool
DEPRECATED_TYPING_ALIASES: dict[str, TypingAlias] = {
"typing.Tuple": TypingAlias("tuple", False),
"typing.List": TypingAlias("list", False),
"typing.Dict": TypingAlias("dict", False),
"typing.Set": TypingAlias("set", False),
"typing.FrozenSet": TypingAlias("frozenset", False),
"typing.Type": TypingAlias("type", False),
"typing.Deque": TypingAlias("collections.deque", True),
"typing.DefaultDict": TypingAlias("collections.defaultdict", True),
"typing.OrderedDict": TypingAlias("collections.OrderedDict", True),
"typing.Counter": TypingAlias("collections.Counter", True),
"typing.ChainMap": TypingAlias("collections.ChainMap", True),
"typing.Awaitable": TypingAlias("collections.abc.Awaitable", True),
"typing.Coroutine": TypingAlias("collections.abc.Coroutine", True),
"typing.AsyncIterable": TypingAlias("collections.abc.AsyncIterable", True),
"typing.AsyncIterator": TypingAlias("collections.abc.AsyncIterator", True),
"typing.AsyncGenerator": TypingAlias("collections.abc.AsyncGenerator", True),
"typing.Iterable": TypingAlias("collections.abc.Iterable", True),
"typing.Iterator": TypingAlias("collections.abc.Iterator", True),
"typing.Generator": TypingAlias("collections.abc.Generator", True),
"typing.Reversible": TypingAlias("collections.abc.Reversible", True),
"typing.Container": TypingAlias("collections.abc.Container", True),
"typing.Collection": TypingAlias("collections.abc.Collection", True),
"typing.Callable": TypingAlias("collections.abc.Callable", True),
"typing.AbstractSet": TypingAlias("collections.abc.Set", False),
"typing.MutableSet": TypingAlias("collections.abc.MutableSet", True),
"typing.Mapping": TypingAlias("collections.abc.Mapping", True),
"typing.MutableMapping": TypingAlias("collections.abc.MutableMapping", True),
"typing.Sequence": TypingAlias("collections.abc.Sequence", True),
"typing.MutableSequence": TypingAlias("collections.abc.MutableSequence", True),
"typing.ByteString": TypingAlias("collections.abc.ByteString", True),
"typing.MappingView": TypingAlias("collections.abc.MappingView", True),
"typing.KeysView": TypingAlias("collections.abc.KeysView", True),
"typing.ItemsView": TypingAlias("collections.abc.ItemsView", True),
"typing.ValuesView": TypingAlias("collections.abc.ValuesView", True),
"typing.ContextManager": TypingAlias("contextlib.AbstractContextManager", False),
"typing.AsyncContextManager": TypingAlias(
"contextlib.AbstractAsyncContextManager", False
),
"typing.Pattern": TypingAlias("re.Pattern", True),
"typing.Match": TypingAlias("re.Match", True),
"typing.Hashable": TypingAlias("collections.abc.Hashable", True),
"typing.Sized": TypingAlias("collections.abc.Sized", True),
}
ALIAS_NAMES = frozenset(key.split(".")[1] for key in DEPRECATED_TYPING_ALIASES)
UNION_NAMES = ("Optional", "Union")
class DeprecatedTypingAliasMsg(NamedTuple):
node: nodes.Name | nodes.Attribute
qname: str
alias: str
parent_subscript: bool = False
class TypingChecker(BaseChecker):
"""Find issue specifically related to type annotations."""
name = "typing"
msgs = {
"W6001": (
"'%s' is deprecated, use '%s' instead",
"deprecated-typing-alias",
"Emitted when a deprecated typing alias is used.",
),
"R6002": (
"'%s' will be deprecated with PY39, consider using '%s' instead%s",
"consider-using-alias",
"Only emitted if 'runtime-typing=no' and a deprecated "
"typing alias is used in a type annotation context in "
"Python 3.7 or 3.8.",
),
"R6003": (
"Consider using alternative Union syntax instead of '%s'%s",
"consider-alternative-union-syntax",
"Emitted when 'typing.Union' or 'typing.Optional' is used "
"instead of the alternative Union syntax 'int | None'.",
),
"E6004": (
"'NoReturn' inside compound types is broken in 3.7.0 / 3.7.1",
"broken-noreturn",
"``typing.NoReturn`` inside compound types is broken in "
"Python 3.7.0 and 3.7.1. If not dependent on runtime introspection, "
"use string annotation instead. E.g. "
"``Callable[..., 'NoReturn']``. https://bugs.python.org/issue34921",
),
"E6005": (
"'collections.abc.Callable' inside Optional and Union is broken in "
"3.9.0 / 3.9.1 (use 'typing.Callable' instead)",
"broken-collections-callable",
"``collections.abc.Callable`` inside Optional and Union is broken in "
"Python 3.9.0 and 3.9.1. Use ``typing.Callable`` for these cases instead. "
"https://bugs.python.org/issue42965",
),
"R6006": (
"Type `%s` is used more than once in union type annotation. Remove redundant typehints.",
"redundant-typehint-argument",
"Duplicated type arguments will be skipped by `mypy` tool, therefore should be "
"removed to avoid confusion.",
),
}
options = (
(
"runtime-typing",
{
"default": True,
"type": "yn",
"metavar": "<y or n>",
"help": (
"Set to ``no`` if the app / library does **NOT** need to "
"support runtime introspection of type annotations. "
"If you use type annotations **exclusively** for type checking "
"of an application, you're probably fine. For libraries, "
"evaluate if some users want to access the type hints "
"at runtime first, e.g., through ``typing.get_type_hints``. "
"Applies to Python versions 3.7 - 3.9"
),
},
),
)
_should_check_typing_alias: bool
"""The use of type aliases (PEP 585) requires Python 3.9
or Python 3.7+ with postponed evaluation.
"""
_should_check_alternative_union_syntax: bool
"""The use of alternative union syntax (PEP 604) requires Python 3.10
or Python 3.7+ with postponed evaluation.
"""
def __init__(self, linter: PyLinter) -> None:
"""Initialize checker instance."""
super().__init__(linter=linter)
self._found_broken_callable_location: bool = False
self._alias_name_collisions: set[str] = set()
self._deprecated_typing_alias_msgs: list[DeprecatedTypingAliasMsg] = []
self._consider_using_alias_msgs: list[DeprecatedTypingAliasMsg] = []
def open(self) -> None:
py_version = self.linter.config.py_version
self._py37_plus = py_version >= (3, 7)
self._py39_plus = py_version >= (3, 9)
self._py310_plus = py_version >= (3, 10)
self._should_check_typing_alias = self._py39_plus or (
self._py37_plus and self.linter.config.runtime_typing is False
)
self._should_check_alternative_union_syntax = self._py310_plus or (
self._py37_plus and self.linter.config.runtime_typing is False
)
self._should_check_noreturn = py_version < (3, 7, 2)
self._should_check_callable = py_version < (3, 9, 2)
def _msg_postponed_eval_hint(self, node: nodes.NodeNG) -> str:
"""Message hint if postponed evaluation isn't enabled."""
if self._py310_plus or "annotations" in node.root().future_imports:
return ""
return ". Add 'from __future__ import annotations' as well"
@only_required_for_messages(
"deprecated-typing-alias",
"consider-using-alias",
"consider-alternative-union-syntax",
"broken-noreturn",
"broken-collections-callable",
)
def visit_name(self, node: nodes.Name) -> None:
if self._should_check_typing_alias and node.name in ALIAS_NAMES:
self._check_for_typing_alias(node)
if self._should_check_alternative_union_syntax and node.name in UNION_NAMES:
self._check_for_alternative_union_syntax(node, node.name)
if self._should_check_noreturn and node.name == "NoReturn":
self._check_broken_noreturn(node)
if self._should_check_callable and node.name == "Callable":
self._check_broken_callable(node)
@only_required_for_messages(
"deprecated-typing-alias",
"consider-using-alias",
"consider-alternative-union-syntax",
"broken-noreturn",
"broken-collections-callable",
)
def visit_attribute(self, node: nodes.Attribute) -> None:
if self._should_check_typing_alias and node.attrname in ALIAS_NAMES:
self._check_for_typing_alias(node)
if self._should_check_alternative_union_syntax and node.attrname in UNION_NAMES:
self._check_for_alternative_union_syntax(node, node.attrname)
if self._should_check_noreturn and node.attrname == "NoReturn":
self._check_broken_noreturn(node)
if self._should_check_callable and node.attrname == "Callable":
self._check_broken_callable(node)
@only_required_for_messages("redundant-typehint-argument")
def visit_annassign(self, node: nodes.AnnAssign) -> None:
annotation = node.annotation
if self._is_deprecated_union_annotation(annotation, "Optional"):
if self._is_optional_none_annotation(annotation):
self.add_message(
"redundant-typehint-argument",
node=annotation,
args="None",
confidence=HIGH,
)
return
if self._is_deprecated_union_annotation(annotation, "Union") and isinstance(
annotation.slice, nodes.Tuple
):
types = annotation.slice.elts
elif self._is_binop_union_annotation(annotation):
types = self._parse_binops_typehints(annotation)
else:
return
self._check_union_types(types, node)
@staticmethod
def _is_deprecated_union_annotation(
annotation: nodes.NodeNG, union_name: str
) -> bool:
return (
isinstance(annotation, nodes.Subscript)
and isinstance(annotation.value, nodes.Name)
and annotation.value.name == union_name
)
def _is_binop_union_annotation(self, annotation: nodes.NodeNG) -> bool:
return self._should_check_alternative_union_syntax and isinstance(
annotation, nodes.BinOp
)
@staticmethod
def _is_optional_none_annotation(annotation: nodes.Subscript) -> bool:
return (
isinstance(annotation.slice, nodes.Const) and annotation.slice.value is None
)
def _parse_binops_typehints(
self, binop_node: nodes.BinOp, typehints_list: list[nodes.NodeNG] | None = None
) -> list[nodes.NodeNG]:
typehints_list = typehints_list or []
if isinstance(binop_node.left, nodes.BinOp):
typehints_list.extend(
self._parse_binops_typehints(binop_node.left, typehints_list)
)
else:
typehints_list.append(binop_node.left)
typehints_list.append(binop_node.right)
return typehints_list
def _check_union_types(
self, types: list[nodes.NodeNG], annotation: nodes.NodeNG
) -> None:
types_set = set()
for typehint in types:
typehint_str = typehint.as_string()
if typehint_str in types_set:
self.add_message(
"redundant-typehint-argument",
node=annotation,
args=(typehint_str),
confidence=HIGH,
)
else:
types_set.add(typehint_str)
def _check_for_alternative_union_syntax(
self,
node: nodes.Name | nodes.Attribute,
name: str,
) -> None:
"""Check if alternative union syntax could be used.
Requires
- Python 3.10
- OR: Python 3.7+ with postponed evaluation in
a type annotation context
"""
inferred = safe_infer(node)
if not (
isinstance(inferred, nodes.FunctionDef)
and inferred.qname() in {"typing.Optional", "typing.Union"}
or isinstance(inferred, astroid.bases.Instance)
and inferred.qname() == "typing._SpecialForm"
):
return
if not (self._py310_plus or is_node_in_type_annotation_context(node)):
return
self.add_message(
"consider-alternative-union-syntax",
node=node,
args=(name, self._msg_postponed_eval_hint(node)),
confidence=INFERENCE,
)
def _check_for_typing_alias(
self,
node: nodes.Name | nodes.Attribute,
) -> None:
"""Check if typing alias is deprecated or could be replaced.
Requires
- Python 3.9
- OR: Python 3.7+ with postponed evaluation in
a type annotation context
For Python 3.7+: Only emit message if change doesn't create
any name collisions, only ever used in a type annotation
context, and can safely be replaced.
"""
inferred = safe_infer(node)
if not isinstance(inferred, nodes.ClassDef):
return
alias = DEPRECATED_TYPING_ALIASES.get(inferred.qname(), None)
if alias is None:
return
if self._py39_plus:
if inferred.qname() == "typing.Callable" and self._broken_callable_location(
node
):
self._found_broken_callable_location = True
self._deprecated_typing_alias_msgs.append(
DeprecatedTypingAliasMsg(
node,
inferred.qname(),
alias.name,
)
)
return
# For PY37+, check for type annotation context first
if not is_node_in_type_annotation_context(node) and isinstance(
node.parent, nodes.Subscript
):
if alias.name_collision is True:
self._alias_name_collisions.add(inferred.qname())
return
self._consider_using_alias_msgs.append(
DeprecatedTypingAliasMsg(
node,
inferred.qname(),
alias.name,
isinstance(node.parent, nodes.Subscript),
)
)
@only_required_for_messages("consider-using-alias", "deprecated-typing-alias")
def leave_module(self, node: nodes.Module) -> None:
"""After parsing of module is complete, add messages for
'consider-using-alias' check.
Make sure results are safe to recommend / collision free.
"""
if self._py39_plus:
for msg in self._deprecated_typing_alias_msgs:
if (
self._found_broken_callable_location
and msg.qname == "typing.Callable"
):
continue
self.add_message(
"deprecated-typing-alias",
node=msg.node,
args=(msg.qname, msg.alias),
confidence=INFERENCE,
)
elif self._py37_plus:
msg_future_import = self._msg_postponed_eval_hint(node)
for msg in self._consider_using_alias_msgs:
if msg.qname in self._alias_name_collisions:
continue
self.add_message(
"consider-using-alias",
node=msg.node,
args=(
msg.qname,
msg.alias,
msg_future_import if msg.parent_subscript else "",
),
confidence=INFERENCE,
)
# Clear all module cache variables
self._found_broken_callable_location = False
self._deprecated_typing_alias_msgs.clear()
self._alias_name_collisions.clear()
self._consider_using_alias_msgs.clear()
def _check_broken_noreturn(self, node: nodes.Name | nodes.Attribute) -> None:
"""Check for 'NoReturn' inside compound types."""
if not isinstance(node.parent, nodes.BaseContainer):
# NoReturn not part of a Union or Callable type
return
if (
in_type_checking_block(node)
or is_postponed_evaluation_enabled(node)
and is_node_in_type_annotation_context(node)
):
return
for inferred in node.infer():
# To deal with typing_extensions, don't use safe_infer
if (
isinstance(inferred, (nodes.FunctionDef, nodes.ClassDef))
and inferred.qname() in TYPING_NORETURN
# In Python 3.7 - 3.8, NoReturn is alias of '_SpecialForm'
or isinstance(inferred, astroid.bases.BaseInstance)
and isinstance(inferred._proxied, nodes.ClassDef)
and inferred._proxied.qname() == "typing._SpecialForm"
):
self.add_message("broken-noreturn", node=node, confidence=INFERENCE)
break
def _check_broken_callable(self, node: nodes.Name | nodes.Attribute) -> None:
"""Check for 'collections.abc.Callable' inside Optional and Union."""
inferred = safe_infer(node)
if not (
isinstance(inferred, nodes.ClassDef)
and inferred.qname() == "_collections_abc.Callable"
and self._broken_callable_location(node)
):
return
self.add_message("broken-collections-callable", node=node, confidence=INFERENCE)
def _broken_callable_location(self, node: nodes.Name | nodes.Attribute) -> bool:
"""Check if node would be a broken location for collections.abc.Callable."""
if (
in_type_checking_block(node)
or is_postponed_evaluation_enabled(node)
and is_node_in_type_annotation_context(node)
):
return False
# Check first Callable arg is a list of arguments -> Callable[[int], None]
if not (
isinstance(node.parent, nodes.Subscript)
and isinstance(node.parent.slice, nodes.Tuple)
and len(node.parent.slice.elts) == 2
and isinstance(node.parent.slice.elts[0], nodes.List)
):
return False
# Check nested inside Optional or Union
parent_subscript = node.parent.parent
if isinstance(parent_subscript, nodes.BaseContainer):
parent_subscript = parent_subscript.parent
if not (
isinstance(parent_subscript, nodes.Subscript)
and isinstance(parent_subscript.value, (nodes.Name, nodes.Attribute))
):
return False
inferred_parent = safe_infer(parent_subscript.value)
if not (
isinstance(inferred_parent, nodes.FunctionDef)
and inferred_parent.qname() in {"typing.Optional", "typing.Union"}
or isinstance(inferred_parent, astroid.bases.Instance)
and inferred_parent.qname() == "typing._SpecialForm"
):
return False
return True
def register(linter: PyLinter) -> None:
linter.register_checker(TypingChecker(linter))
|