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craftbeerpi4-pione/venv/lib/python3.8/site-packages/pylint/checkers/utils.py

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# -*- coding: utf-8 -*-
# Copyright (c) 2006-2007, 2009-2014 LOGILAB S.A. (Paris, FRANCE) <contact@logilab.fr>
# Copyright (c) 2009 Mads Kiilerich <mads@kiilerich.com>
# Copyright (c) 2010 Daniel Harding <dharding@gmail.com>
# Copyright (c) 2012-2014 Google, Inc.
# Copyright (c) 2012 FELD Boris <lothiraldan@gmail.com>
# Copyright (c) 2013-2020 Claudiu Popa <pcmanticore@gmail.com>
# Copyright (c) 2014 Brett Cannon <brett@python.org>
# Copyright (c) 2014 Ricardo Gemignani <ricardo.gemignani@gmail.com>
# Copyright (c) 2014 Arun Persaud <arun@nubati.net>
# Copyright (c) 2015 Dmitry Pribysh <dmand@yandex.ru>
# Copyright (c) 2015 Florian Bruhin <me@the-compiler.org>
# Copyright (c) 2015 Radu Ciorba <radu@devrandom.ro>
# Copyright (c) 2015 Ionel Cristian Maries <contact@ionelmc.ro>
# Copyright (c) 2016, 2018-2019 Ashley Whetter <ashley@awhetter.co.uk>
# Copyright (c) 2016-2017 Łukasz Rogalski <rogalski.91@gmail.com>
# Copyright (c) 2016-2017 Moises Lopez <moylop260@vauxoo.com>
# Copyright (c) 2016 Brian C. Lane <bcl@redhat.com>
# Copyright (c) 2017-2018 hippo91 <guillaume.peillex@gmail.com>
# Copyright (c) 2017 ttenhoeve-aa <ttenhoeve@appannie.com>
# Copyright (c) 2018 Alan Chan <achan961117@gmail.com>
# Copyright (c) 2018 Sushobhit <31987769+sushobhit27@users.noreply.github.com>
# Copyright (c) 2018 Yury Gribov <tetra2005@gmail.com>
# Copyright (c) 2018 Caio Carrara <ccarrara@redhat.com>
# Copyright (c) 2018 ssolanki <sushobhitsolanki@gmail.com>
# Copyright (c) 2018 Bryce Guinta <bryce.guinta@protonmail.com>
# Copyright (c) 2018 Bryce Guinta <bryce.paul.guinta@gmail.com>
# Copyright (c) 2018 Ville Skyttä <ville.skytta@iki.fi>
# Copyright (c) 2018 Brian Shaginaw <brian.shaginaw@warbyparker.com>
# Copyright (c) 2019 Matthijs Blom <19817960+MatthijsBlom@users.noreply.github.com>
# Copyright (c) 2019 Djailla <bastien.vallet@gmail.com>
# Copyright (c) 2019 Hugo van Kemenade <hugovk@users.noreply.github.com>
# Copyright (c) 2019 Pierre Sassoulas <pierre.sassoulas@gmail.com>
# Copyright (c) 2019 Nathan Marrow <nmarrow@google.com>
# Copyright (c) 2019 Svet <svet@hyperscience.com>
# Copyright (c) 2019 Pascal Corpet <pcorpet@users.noreply.github.com>
# Copyright (c) 2020 Damien Baty <damien.baty@polyconseil.fr>
# Copyright (c) 2020 Andrew Simmons <anjsimmo@gmail.com>
# Copyright (c) 2020 Ram Rachum <ram@rachum.com>
# Copyright (c) 2020 Slavfox <slavfoxman@gmail.com>
# Copyright (c) 2020 Anthony Sottile <asottile@umich.edu>
# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
# For details: https://github.com/PyCQA/pylint/blob/master/COPYING
"""some functions that may be useful for various checkers
"""
import builtins
import itertools
import numbers
import re
import string
from functools import lru_cache, partial
from typing import Callable, Dict, Iterable, List, Match, Optional, Set, Tuple, Union
import _string
import astroid
from astroid import bases as _bases
from astroid import helpers, scoped_nodes
from astroid.exceptions import _NonDeducibleTypeHierarchy
BUILTINS_NAME = builtins.__name__
COMP_NODE_TYPES = (
astroid.ListComp,
astroid.SetComp,
astroid.DictComp,
astroid.GeneratorExp,
)
EXCEPTIONS_MODULE = "builtins"
ABC_MODULES = {"abc", "_py_abc"}
ABC_METHODS = {
"abc.abstractproperty",
"abc.abstractmethod",
"abc.abstractclassmethod",
"abc.abstractstaticmethod",
}
TYPING_PROTOCOLS = frozenset({"typing.Protocol", "typing_extensions.Protocol"})
ITER_METHOD = "__iter__"
AITER_METHOD = "__aiter__"
NEXT_METHOD = "__next__"
GETITEM_METHOD = "__getitem__"
CLASS_GETITEM_METHOD = "__class_getitem__"
SETITEM_METHOD = "__setitem__"
DELITEM_METHOD = "__delitem__"
CONTAINS_METHOD = "__contains__"
KEYS_METHOD = "keys"
# Dictionary which maps the number of expected parameters a
# special method can have to a set of special methods.
# The following keys are used to denote the parameters restrictions:
#
# * None: variable number of parameters
# * number: exactly that number of parameters
# * tuple: this are the odd ones. Basically it means that the function
# can work with any number of arguments from that tuple,
# although it's best to implement it in order to accept
# all of them.
_SPECIAL_METHODS_PARAMS = {
None: ("__new__", "__init__", "__call__"),
0: (
"__del__",
"__repr__",
"__str__",
"__bytes__",
"__hash__",
"__bool__",
"__dir__",
"__len__",
"__length_hint__",
"__iter__",
"__reversed__",
"__neg__",
"__pos__",
"__abs__",
"__invert__",
"__complex__",
"__int__",
"__float__",
"__index__",
"__trunc__",
"__floor__",
"__ceil__",
"__enter__",
"__aenter__",
"__getnewargs_ex__",
"__getnewargs__",
"__getstate__",
"__reduce__",
"__copy__",
"__unicode__",
"__nonzero__",
"__await__",
"__aiter__",
"__anext__",
"__fspath__",
),
1: (
"__format__",
"__lt__",
"__le__",
"__eq__",
"__ne__",
"__gt__",
"__ge__",
"__getattr__",
"__getattribute__",
"__delattr__",
"__delete__",
"__instancecheck__",
"__subclasscheck__",
"__getitem__",
"__missing__",
"__delitem__",
"__contains__",
"__add__",
"__sub__",
"__mul__",
"__truediv__",
"__floordiv__",
"__rfloordiv__",
"__mod__",
"__divmod__",
"__lshift__",
"__rshift__",
"__and__",
"__xor__",
"__or__",
"__radd__",
"__rsub__",
"__rmul__",
"__rtruediv__",
"__rmod__",
"__rdivmod__",
"__rpow__",
"__rlshift__",
"__rrshift__",
"__rand__",
"__rxor__",
"__ror__",
"__iadd__",
"__isub__",
"__imul__",
"__itruediv__",
"__ifloordiv__",
"__imod__",
"__ilshift__",
"__irshift__",
"__iand__",
"__ixor__",
"__ior__",
"__ipow__",
"__setstate__",
"__reduce_ex__",
"__deepcopy__",
"__cmp__",
"__matmul__",
"__rmatmul__",
"__imatmul__",
"__div__",
),
2: ("__setattr__", "__get__", "__set__", "__setitem__", "__set_name__"),
3: ("__exit__", "__aexit__"),
(0, 1): ("__round__",),
(1, 2): ("__pow__",),
}
SPECIAL_METHODS_PARAMS = {
name: params
for params, methods in _SPECIAL_METHODS_PARAMS.items()
for name in methods # type: ignore
}
PYMETHODS = set(SPECIAL_METHODS_PARAMS)
class NoSuchArgumentError(Exception):
pass
def is_inside_except(node):
"""Returns true if node is inside the name of an except handler."""
current = node
while current and not isinstance(current.parent, astroid.ExceptHandler):
current = current.parent
return current and current is current.parent.name
def is_inside_lambda(node: astroid.node_classes.NodeNG) -> bool:
"""Return true if given node is inside lambda"""
parent = node.parent
while parent is not None:
if isinstance(parent, astroid.Lambda):
return True
parent = parent.parent
return False
def get_all_elements(
node: astroid.node_classes.NodeNG,
) -> Iterable[astroid.node_classes.NodeNG]:
"""Recursively returns all atoms in nested lists and tuples."""
if isinstance(node, (astroid.Tuple, astroid.List)):
for child in node.elts:
yield from get_all_elements(child)
else:
yield node
def clobber_in_except(
node: astroid.node_classes.NodeNG,
) -> Tuple[bool, Optional[Tuple[str, str]]]:
"""Checks if an assignment node in an except handler clobbers an existing
variable.
Returns (True, args for W0623) if assignment clobbers an existing variable,
(False, None) otherwise.
"""
if isinstance(node, astroid.AssignAttr):
return True, (node.attrname, "object %r" % (node.expr.as_string(),))
if isinstance(node, astroid.AssignName):
name = node.name
if is_builtin(name):
return True, (name, "builtins")
stmts = node.lookup(name)[1]
if stmts and not isinstance(
stmts[0].assign_type(),
(astroid.Assign, astroid.AugAssign, astroid.ExceptHandler),
):
return True, (name, "outer scope (line %s)" % stmts[0].fromlineno)
return False, None
def is_super(node: astroid.node_classes.NodeNG) -> bool:
"""return True if the node is referencing the "super" builtin function
"""
if getattr(node, "name", None) == "super" and node.root().name == BUILTINS_NAME:
return True
return False
def is_error(node: astroid.scoped_nodes.FunctionDef) -> bool:
"""Return true if the given function node only raises an exception"""
return len(node.body) == 1 and isinstance(node.body[0], astroid.Raise)
builtins = builtins.__dict__.copy() # type: ignore
SPECIAL_BUILTINS = ("__builtins__",) # '__path__', '__file__')
def is_builtin_object(node: astroid.node_classes.NodeNG) -> bool:
"""Returns True if the given node is an object from the __builtin__ module."""
return node and node.root().name == BUILTINS_NAME
def is_builtin(name: str) -> bool:
"""return true if <name> could be considered as a builtin defined by python
"""
return name in builtins or name in SPECIAL_BUILTINS # type: ignore
def is_defined_in_scope(
var_node: astroid.node_classes.NodeNG,
varname: str,
scope: astroid.node_classes.NodeNG,
) -> bool:
if isinstance(scope, astroid.If):
for node in scope.body:
if (
isinstance(node, astroid.Assign)
and any(
isinstance(target, astroid.AssignName) and target.name == varname
for target in node.targets
)
) or (isinstance(node, astroid.Nonlocal) and varname in node.names):
return True
elif isinstance(scope, (COMP_NODE_TYPES, astroid.For)):
for ass_node in scope.nodes_of_class(astroid.AssignName):
if ass_node.name == varname:
return True
elif isinstance(scope, astroid.With):
for expr, ids in scope.items:
if expr.parent_of(var_node):
break
if ids and isinstance(ids, astroid.AssignName) and ids.name == varname:
return True
elif isinstance(scope, (astroid.Lambda, astroid.FunctionDef)):
if scope.args.is_argument(varname):
# If the name is found inside a default value
# of a function, then let the search continue
# in the parent's tree.
if scope.args.parent_of(var_node):
try:
scope.args.default_value(varname)
scope = scope.parent
is_defined_in_scope(var_node, varname, scope)
except astroid.NoDefault:
pass
return True
if getattr(scope, "name", None) == varname:
return True
elif isinstance(scope, astroid.ExceptHandler):
if isinstance(scope.name, astroid.AssignName):
ass_node = scope.name
if ass_node.name == varname:
return True
return False
def is_defined_before(var_node: astroid.Name) -> bool:
"""Check if the given variable node is defined before
Verify that the variable node is defined by a parent node
(list, set, dict, or generator comprehension, lambda)
or in a previous sibling node on the same line
(statement_defining ; statement_using).
"""
varname = var_node.name
_node = var_node.parent
while _node:
if is_defined_in_scope(var_node, varname, _node):
return True
_node = _node.parent
# possibly multiple statements on the same line using semi colon separator
stmt = var_node.statement()
_node = stmt.previous_sibling()
lineno = stmt.fromlineno
while _node and _node.fromlineno == lineno:
for assign_node in _node.nodes_of_class(astroid.AssignName):
if assign_node.name == varname:
return True
for imp_node in _node.nodes_of_class((astroid.ImportFrom, astroid.Import)):
if varname in [name[1] or name[0] for name in imp_node.names]:
return True
_node = _node.previous_sibling()
return False
def is_default_argument(
node: astroid.node_classes.NodeNG,
scope: Optional[astroid.node_classes.NodeNG] = None,
) -> bool:
"""return true if the given Name node is used in function or lambda
default argument's value
"""
if not scope:
scope = node.scope()
if isinstance(scope, (astroid.FunctionDef, astroid.Lambda)):
for default_node in scope.args.defaults:
for default_name_node in default_node.nodes_of_class(astroid.Name):
if default_name_node is node:
return True
return False
def is_func_decorator(node: astroid.node_classes.NodeNG) -> bool:
"""return true if the name is used in function decorator"""
parent = node.parent
while parent is not None:
if isinstance(parent, astroid.Decorators):
return True
if parent.is_statement or isinstance(
parent,
(astroid.Lambda, scoped_nodes.ComprehensionScope, scoped_nodes.ListComp),
):
break
parent = parent.parent
return False
def is_ancestor_name(
frame: astroid.ClassDef, node: astroid.node_classes.NodeNG
) -> bool:
"""return True if `frame` is an astroid.Class node with `node` in the
subtree of its bases attribute
"""
if not isinstance(frame, astroid.ClassDef):
return False
for base in frame.bases:
if node in base.nodes_of_class(astroid.Name):
return True
return False
def assign_parent(node: astroid.node_classes.NodeNG) -> astroid.node_classes.NodeNG:
"""return the higher parent which is not an AssignName, Tuple or List node
"""
while node and isinstance(node, (astroid.AssignName, astroid.Tuple, astroid.List)):
node = node.parent
return node
def overrides_a_method(class_node: astroid.ClassDef, name: str) -> bool:
"""return True if <name> is a method overridden from an ancestor"""
for ancestor in class_node.ancestors():
if name in ancestor and isinstance(ancestor[name], astroid.FunctionDef):
return True
return False
def check_messages(*messages: str) -> Callable:
"""decorator to store messages that are handled by a checker method"""
def store_messages(func):
func.checks_msgs = messages
return func
return store_messages
class IncompleteFormatString(Exception):
"""A format string ended in the middle of a format specifier."""
class UnsupportedFormatCharacter(Exception):
"""A format character in a format string is not one of the supported
format characters."""
def __init__(self, index):
Exception.__init__(self, index)
self.index = index
def parse_format_string(
format_string: str,
) -> Tuple[Set[str], int, Dict[str, str], List[str]]:
"""Parses a format string, returning a tuple of (keys, num_args), where keys
is the set of mapping keys in the format string, and num_args is the number
of arguments required by the format string. Raises
IncompleteFormatString or UnsupportedFormatCharacter if a
parse error occurs."""
keys = set()
key_types = dict()
pos_types = []
num_args = 0
def next_char(i):
i += 1
if i == len(format_string):
raise IncompleteFormatString
return (i, format_string[i])
i = 0
while i < len(format_string):
char = format_string[i]
if char == "%":
i, char = next_char(i)
# Parse the mapping key (optional).
key = None
if char == "(":
depth = 1
i, char = next_char(i)
key_start = i
while depth != 0:
if char == "(":
depth += 1
elif char == ")":
depth -= 1
i, char = next_char(i)
key_end = i - 1
key = format_string[key_start:key_end]
# Parse the conversion flags (optional).
while char in "#0- +":
i, char = next_char(i)
# Parse the minimum field width (optional).
if char == "*":
num_args += 1
i, char = next_char(i)
else:
while char in string.digits:
i, char = next_char(i)
# Parse the precision (optional).
if char == ".":
i, char = next_char(i)
if char == "*":
num_args += 1
i, char = next_char(i)
else:
while char in string.digits:
i, char = next_char(i)
# Parse the length modifier (optional).
if char in "hlL":
i, char = next_char(i)
# Parse the conversion type (mandatory).
flags = "diouxXeEfFgGcrs%a"
if char not in flags:
raise UnsupportedFormatCharacter(i)
if key:
keys.add(key)
key_types[key] = char
elif char != "%":
num_args += 1
pos_types.append(char)
i += 1
return keys, num_args, key_types, pos_types
def split_format_field_names(format_string) -> Tuple[str, Iterable[Tuple[bool, str]]]:
try:
return _string.formatter_field_name_split(format_string)
except ValueError as e:
raise IncompleteFormatString() from e
def collect_string_fields(format_string) -> Iterable[Optional[str]]:
""" Given a format string, return an iterator
of all the valid format fields. It handles nested fields
as well.
"""
formatter = string.Formatter()
try:
parseiterator = formatter.parse(format_string)
for result in parseiterator:
if all(item is None for item in result[1:]):
# not a replacement format
continue
name = result[1]
nested = result[2]
yield name
if nested:
yield from collect_string_fields(nested)
except ValueError as exc:
# Probably the format string is invalid.
if exc.args[0].startswith("cannot switch from manual"):
# On Jython, parsing a string with both manual
# and automatic positions will fail with a ValueError,
# while on CPython it will simply return the fields,
# the validation being done in the interpreter (?).
# We're just returning two mixed fields in order
# to trigger the format-combined-specification check.
yield ""
yield "1"
return
raise IncompleteFormatString(format_string) from exc
def parse_format_method_string(
format_string: str,
) -> Tuple[List[Tuple[str, List[Tuple[bool, str]]]], int, int]:
"""
Parses a PEP 3101 format string, returning a tuple of
(keyword_arguments, implicit_pos_args_cnt, explicit_pos_args),
where keyword_arguments is the set of mapping keys in the format string, implicit_pos_args_cnt
is the number of arguments required by the format string and
explicit_pos_args is the number of arguments passed with the position.
"""
keyword_arguments = []
implicit_pos_args_cnt = 0
explicit_pos_args = set()
for name in collect_string_fields(format_string):
if name and str(name).isdigit():
explicit_pos_args.add(str(name))
elif name:
keyname, fielditerator = split_format_field_names(name)
if isinstance(keyname, numbers.Number):
explicit_pos_args.add(str(keyname))
try:
keyword_arguments.append((keyname, list(fielditerator)))
except ValueError as e:
raise IncompleteFormatString() from e
else:
implicit_pos_args_cnt += 1
return keyword_arguments, implicit_pos_args_cnt, len(explicit_pos_args)
def is_attr_protected(attrname: str) -> bool:
"""return True if attribute name is protected (start with _ and some other
details), False otherwise.
"""
return (
attrname[0] == "_"
and attrname != "_"
and not (attrname.startswith("__") and attrname.endswith("__"))
)
def node_frame_class(node: astroid.node_classes.NodeNG) -> Optional[astroid.ClassDef]:
"""Return the class that is wrapping the given node
The function returns a class for a method node (or a staticmethod or a
classmethod), otherwise it returns `None`.
"""
klass = node.frame()
nodes_to_check = (
astroid.node_classes.NodeNG,
astroid.UnboundMethod,
astroid.BaseInstance,
)
while (
klass
and isinstance(klass, nodes_to_check)
and not isinstance(klass, astroid.ClassDef)
):
if klass.parent is None:
klass = None
else:
klass = klass.parent.frame()
return klass
def is_attr_private(attrname: str) -> Optional[Match[str]]:
"""Check that attribute name is private (at least two leading underscores,
at most one trailing underscore)
"""
regex = re.compile("^_{2,}.*[^_]+_?$")
return regex.match(attrname)
def get_argument_from_call(
call_node: astroid.Call, position: int = None, keyword: str = None
) -> astroid.Name:
"""Returns the specified argument from a function call.
:param astroid.Call call_node: Node representing a function call to check.
:param int position: position of the argument.
:param str keyword: the keyword of the argument.
:returns: The node representing the argument, None if the argument is not found.
:rtype: astroid.Name
:raises ValueError: if both position and keyword are None.
:raises NoSuchArgumentError: if no argument at the provided position or with
the provided keyword.
"""
if position is None and keyword is None:
raise ValueError("Must specify at least one of: position or keyword.")
if position is not None:
try:
return call_node.args[position]
except IndexError:
pass
if keyword and call_node.keywords:
for arg in call_node.keywords:
if arg.arg == keyword:
return arg.value
raise NoSuchArgumentError
def inherit_from_std_ex(node: astroid.node_classes.NodeNG) -> bool:
"""
Return true if the given class node is subclass of
exceptions.Exception.
"""
ancestors = node.ancestors() if hasattr(node, "ancestors") else []
for ancestor in itertools.chain([node], ancestors):
if (
ancestor.name in ("Exception", "BaseException")
and ancestor.root().name == EXCEPTIONS_MODULE
):
return True
return False
def error_of_type(handler: astroid.ExceptHandler, error_type) -> bool:
"""
Check if the given exception handler catches
the given error_type.
The *handler* parameter is a node, representing an ExceptHandler node.
The *error_type* can be an exception, such as AttributeError,
the name of an exception, or it can be a tuple of errors.
The function will return True if the handler catches any of the
given errors.
"""
def stringify_error(error):
if not isinstance(error, str):
return error.__name__
return error
if not isinstance(error_type, tuple):
error_type = (error_type,) # type: ignore
expected_errors = {stringify_error(error) for error in error_type} # type: ignore
if not handler.type:
return False
return handler.catch(expected_errors)
def decorated_with_property(node: astroid.FunctionDef) -> bool:
"""Detect if the given function node is decorated with a property. """
if not node.decorators:
return False
for decorator in node.decorators.nodes:
try:
if _is_property_decorator(decorator):
return True
except astroid.InferenceError:
pass
return False
def _is_property_kind(node, *kinds):
if not isinstance(node, (astroid.UnboundMethod, astroid.FunctionDef)):
return False
if node.decorators:
for decorator in node.decorators.nodes:
if isinstance(decorator, astroid.Attribute) and decorator.attrname in kinds:
return True
return False
def is_property_setter(node: astroid.FunctionDef) -> bool:
"""Check if the given node is a property setter"""
return _is_property_kind(node, "setter")
def is_property_deleter(node: astroid.FunctionDef) -> bool:
"""Check if the given node is a property deleter"""
return _is_property_kind(node, "deleter")
def is_property_setter_or_deleter(node: astroid.FunctionDef) -> bool:
"""Check if the given node is either a property setter or a deleter"""
return _is_property_kind(node, "setter", "deleter")
def _is_property_decorator(decorator: astroid.Name) -> bool:
for inferred in decorator.infer():
if isinstance(inferred, astroid.ClassDef):
if inferred.root().name == BUILTINS_NAME and inferred.name == "property":
return True
for ancestor in inferred.ancestors():
if (
ancestor.name == "property"
and ancestor.root().name == BUILTINS_NAME
):
return True
return False
def decorated_with(
func: Union[astroid.FunctionDef, astroid.BoundMethod, astroid.UnboundMethod],
qnames: Iterable[str],
) -> bool:
"""Determine if the `func` node has a decorator with the qualified name `qname`."""
decorators = func.decorators.nodes if func.decorators else []
for decorator_node in decorators:
if isinstance(decorator_node, astroid.Call):
# We only want to infer the function name
decorator_node = decorator_node.func
try:
if any(
i is not None and i.qname() in qnames or i.name in qnames
for i in decorator_node.infer()
):
return True
except astroid.InferenceError:
continue
return False
@lru_cache(maxsize=1024)
def unimplemented_abstract_methods(
node: astroid.ClassDef, is_abstract_cb: astroid.FunctionDef = None
) -> Dict[str, astroid.node_classes.NodeNG]:
"""
Get the unimplemented abstract methods for the given *node*.
A method can be considered abstract if the callback *is_abstract_cb*
returns a ``True`` value. The check defaults to verifying that
a method is decorated with abstract methods.
The function will work only for new-style classes. For old-style
classes, it will simply return an empty dictionary.
For the rest of them, it will return a dictionary of abstract method
names and their inferred objects.
"""
if is_abstract_cb is None:
is_abstract_cb = partial(decorated_with, qnames=ABC_METHODS)
visited = {} # type: Dict[str, astroid.node_classes.NodeNG]
try:
mro = reversed(node.mro())
except NotImplementedError:
# Old style class, it will not have a mro.
return {}
except astroid.ResolveError:
# Probably inconsistent hierarchy, don'try
# to figure this out here.
return {}
for ancestor in mro:
for obj in ancestor.values():
inferred = obj
if isinstance(obj, astroid.AssignName):
inferred = safe_infer(obj)
if not inferred:
# Might be an abstract function,
# but since we don't have enough information
# in order to take this decision, we're taking
# the *safe* decision instead.
if obj.name in visited:
del visited[obj.name]
continue
if not isinstance(inferred, astroid.FunctionDef):
if obj.name in visited:
del visited[obj.name]
if isinstance(inferred, astroid.FunctionDef):
# It's critical to use the original name,
# since after inferring, an object can be something
# else than expected, as in the case of the
# following assignment.
#
# class A:
# def keys(self): pass
# __iter__ = keys
abstract = is_abstract_cb(inferred)
if abstract:
visited[obj.name] = inferred
elif not abstract and obj.name in visited:
del visited[obj.name]
return visited
def find_try_except_wrapper_node(
node: astroid.node_classes.NodeNG,
) -> Optional[Union[astroid.ExceptHandler, astroid.TryExcept]]:
"""Return the ExceptHandler or the TryExcept node in which the node is."""
current = node
ignores = (astroid.ExceptHandler, astroid.TryExcept)
while current and not isinstance(current.parent, ignores):
current = current.parent
if current and isinstance(current.parent, ignores):
return current.parent
return None
def find_except_wrapper_node_in_scope(
node: astroid.node_classes.NodeNG,
) -> Optional[Union[astroid.ExceptHandler, astroid.TryExcept]]:
"""Return the ExceptHandler in which the node is, without going out of scope."""
current = node
while current.parent is not None:
current = current.parent
if isinstance(current, astroid.scoped_nodes.LocalsDictNodeNG):
# If we're inside a function/class definition, we don't want to keep checking
# higher ancestors for `except` clauses, because if these exist, it means our
# function/class was defined in an `except` clause, rather than the current code
# actually running in an `except` clause.
return None
if isinstance(current, astroid.ExceptHandler):
return current
return None
def is_from_fallback_block(node: astroid.node_classes.NodeNG) -> bool:
"""Check if the given node is from a fallback import block."""
context = find_try_except_wrapper_node(node)
if not context:
return False
if isinstance(context, astroid.ExceptHandler):
other_body = context.parent.body
handlers = context.parent.handlers
else:
other_body = itertools.chain.from_iterable(
handler.body for handler in context.handlers
)
handlers = context.handlers
has_fallback_imports = any(
isinstance(import_node, (astroid.ImportFrom, astroid.Import))
for import_node in other_body
)
ignores_import_error = _except_handlers_ignores_exception(handlers, ImportError)
return ignores_import_error or has_fallback_imports
def _except_handlers_ignores_exception(
handlers: astroid.ExceptHandler, exception
) -> bool:
func = partial(error_of_type, error_type=(exception,))
return any(map(func, handlers))
def get_exception_handlers(
node: astroid.node_classes.NodeNG, exception=Exception
) -> Optional[List[astroid.ExceptHandler]]:
"""Return the collections of handlers handling the exception in arguments.
Args:
node (astroid.NodeNG): A node that is potentially wrapped in a try except.
exception (builtin.Exception or str): exception or name of the exception.
Returns:
list: the collection of handlers that are handling the exception or None.
"""
context = find_try_except_wrapper_node(node)
if isinstance(context, astroid.TryExcept):
return [
handler for handler in context.handlers if error_of_type(handler, exception)
]
return []
def is_node_inside_try_except(node: astroid.Raise) -> bool:
"""Check if the node is directly under a Try/Except statement.
(but not under an ExceptHandler!)
Args:
node (astroid.Raise): the node raising the exception.
Returns:
bool: True if the node is inside a try/except statement, False otherwise.
"""
context = find_try_except_wrapper_node(node)
return isinstance(context, astroid.TryExcept)
def node_ignores_exception(
node: astroid.node_classes.NodeNG, exception=Exception
) -> bool:
"""Check if the node is in a TryExcept which handles the given exception.
If the exception is not given, the function is going to look for bare
excepts.
"""
managing_handlers = get_exception_handlers(node, exception)
if not managing_handlers:
return False
return any(managing_handlers)
def class_is_abstract(node: astroid.ClassDef) -> bool:
"""return true if the given class node should be considered as an abstract
class
"""
# Only check for explicit metaclass=ABCMeta on this specific class
meta = node.declared_metaclass()
if meta is not None:
if meta.name == "ABCMeta" and meta.root().name in ABC_MODULES:
return True
for ancestor in node.ancestors():
if ancestor.name == "ABC" and ancestor.root().name in ABC_MODULES:
# abc.ABC inheritance
return True
for method in node.methods():
if method.parent.frame() is node:
if method.is_abstract(pass_is_abstract=False):
return True
return False
def _supports_protocol_method(value: astroid.node_classes.NodeNG, attr: str) -> bool:
try:
attributes = value.getattr(attr)
except astroid.NotFoundError:
return False
first = attributes[0]
if isinstance(first, astroid.AssignName):
if isinstance(first.parent.value, astroid.Const):
return False
return True
def is_comprehension(node: astroid.node_classes.NodeNG) -> bool:
comprehensions = (
astroid.ListComp,
astroid.SetComp,
astroid.DictComp,
astroid.GeneratorExp,
)
return isinstance(node, comprehensions)
def _supports_mapping_protocol(value: astroid.node_classes.NodeNG) -> bool:
return _supports_protocol_method(
value, GETITEM_METHOD
) and _supports_protocol_method(value, KEYS_METHOD)
def _supports_membership_test_protocol(value: astroid.node_classes.NodeNG) -> bool:
return _supports_protocol_method(value, CONTAINS_METHOD)
def _supports_iteration_protocol(value: astroid.node_classes.NodeNG) -> bool:
return _supports_protocol_method(value, ITER_METHOD) or _supports_protocol_method(
value, GETITEM_METHOD
)
def _supports_async_iteration_protocol(value: astroid.node_classes.NodeNG) -> bool:
return _supports_protocol_method(value, AITER_METHOD)
def _supports_getitem_protocol(value: astroid.node_classes.NodeNG) -> bool:
return _supports_protocol_method(value, GETITEM_METHOD)
def _supports_setitem_protocol(value: astroid.node_classes.NodeNG) -> bool:
return _supports_protocol_method(value, SETITEM_METHOD)
def _supports_delitem_protocol(value: astroid.node_classes.NodeNG) -> bool:
return _supports_protocol_method(value, DELITEM_METHOD)
def _is_abstract_class_name(name: str) -> bool:
lname = name.lower()
is_mixin = lname.endswith("mixin")
is_abstract = lname.startswith("abstract")
is_base = lname.startswith("base") or lname.endswith("base")
return is_mixin or is_abstract or is_base
def is_inside_abstract_class(node: astroid.node_classes.NodeNG) -> bool:
while node is not None:
if isinstance(node, astroid.ClassDef):
if class_is_abstract(node):
return True
name = getattr(node, "name", None)
if name is not None and _is_abstract_class_name(name):
return True
node = node.parent
return False
def _supports_protocol(
value: astroid.node_classes.NodeNG, protocol_callback: astroid.FunctionDef
) -> bool:
if isinstance(value, astroid.ClassDef):
if not has_known_bases(value):
return True
# classobj can only be iterable if it has an iterable metaclass
meta = value.metaclass()
if meta is not None:
if protocol_callback(meta):
return True
if isinstance(value, astroid.BaseInstance):
if not has_known_bases(value):
return True
if value.has_dynamic_getattr():
return True
if protocol_callback(value):
return True
if (
isinstance(value, _bases.Proxy)
and isinstance(value._proxied, astroid.BaseInstance)
and has_known_bases(value._proxied)
):
value = value._proxied
return protocol_callback(value)
return False
def is_iterable(value: astroid.node_classes.NodeNG, check_async: bool = False) -> bool:
if check_async:
protocol_check = _supports_async_iteration_protocol
else:
protocol_check = _supports_iteration_protocol
return _supports_protocol(value, protocol_check)
def is_mapping(value: astroid.node_classes.NodeNG) -> bool:
return _supports_protocol(value, _supports_mapping_protocol)
def supports_membership_test(value: astroid.node_classes.NodeNG) -> bool:
supported = _supports_protocol(value, _supports_membership_test_protocol)
return supported or is_iterable(value)
def supports_getitem(value: astroid.node_classes.NodeNG) -> bool:
if isinstance(value, astroid.ClassDef):
if _supports_protocol_method(value, CLASS_GETITEM_METHOD):
return True
return _supports_protocol(value, _supports_getitem_protocol)
def supports_setitem(value: astroid.node_classes.NodeNG) -> bool:
return _supports_protocol(value, _supports_setitem_protocol)
def supports_delitem(value: astroid.node_classes.NodeNG) -> bool:
return _supports_protocol(value, _supports_delitem_protocol)
def _get_python_type_of_node(node):
pytype = getattr(node, "pytype", None)
if callable(pytype):
return pytype()
return None
@lru_cache(maxsize=1024)
def safe_infer(
node: astroid.node_classes.NodeNG, context=None
) -> Optional[astroid.node_classes.NodeNG]:
"""Return the inferred value for the given node.
Return None if inference failed or if there is some ambiguity (more than
one node has been inferred of different types).
"""
inferred_types = set()
try:
infer_gen = node.infer(context=context)
value = next(infer_gen)
except astroid.InferenceError:
return None
if value is not astroid.Uninferable:
inferred_types.add(_get_python_type_of_node(value))
try:
for inferred in infer_gen:
inferred_type = _get_python_type_of_node(inferred)
if inferred_type not in inferred_types:
return None # If there is ambiguity on the inferred node.
except astroid.InferenceError:
return None # There is some kind of ambiguity
except StopIteration:
return value
return value if len(inferred_types) <= 1 else None
def has_known_bases(klass: astroid.ClassDef, context=None) -> bool:
"""Return true if all base classes of a class could be inferred."""
try:
return klass._all_bases_known
except AttributeError:
pass
for base in klass.bases:
result = safe_infer(base, context=context)
if (
not isinstance(result, astroid.ClassDef)
or result is klass
or not has_known_bases(result, context=context)
):
klass._all_bases_known = False
return False
klass._all_bases_known = True
return True
def is_none(node: astroid.node_classes.NodeNG) -> bool:
return (
node is None
or (isinstance(node, astroid.Const) and node.value is None)
or (isinstance(node, astroid.Name) and node.name == "None")
)
def node_type(node: astroid.node_classes.NodeNG) -> Optional[type]:
"""Return the inferred type for `node`
If there is more than one possible type, or if inferred type is Uninferable or None,
return None
"""
# check there is only one possible type for the assign node. Else we
# don't handle it for now
types = set()
try:
for var_type in node.infer():
if var_type == astroid.Uninferable or is_none(var_type):
continue
types.add(var_type)
if len(types) > 1:
return None
except astroid.InferenceError:
return None
return types.pop() if types else None
def is_registered_in_singledispatch_function(node: astroid.FunctionDef) -> bool:
"""Check if the given function node is a singledispatch function."""
singledispatch_qnames = (
"functools.singledispatch",
"singledispatch.singledispatch",
)
if not isinstance(node, astroid.FunctionDef):
return False
decorators = node.decorators.nodes if node.decorators else []
for decorator in decorators:
# func.register are function calls
if not isinstance(decorator, astroid.Call):
continue
func = decorator.func
if not isinstance(func, astroid.Attribute) or func.attrname != "register":
continue
try:
func_def = next(func.expr.infer())
except astroid.InferenceError:
continue
if isinstance(func_def, astroid.FunctionDef):
# pylint: disable=redundant-keyword-arg; some flow inference goes wrong here
return decorated_with(func_def, singledispatch_qnames)
return False
def get_node_last_lineno(node: astroid.node_classes.NodeNG) -> int:
"""
Get the last lineno of the given node. For a simple statement this will just be node.lineno,
but for a node that has child statements (e.g. a method) this will be the lineno of the last
child statement recursively.
"""
# 'finalbody' is always the last clause in a try statement, if present
if getattr(node, "finalbody", False):
return get_node_last_lineno(node.finalbody[-1])
# For if, while, and for statements 'orelse' is always the last clause.
# For try statements 'orelse' is the last in the absence of a 'finalbody'
if getattr(node, "orelse", False):
return get_node_last_lineno(node.orelse[-1])
# try statements have the 'handlers' last if there is no 'orelse' or 'finalbody'
if getattr(node, "handlers", False):
return get_node_last_lineno(node.handlers[-1])
# All compound statements have a 'body'
if getattr(node, "body", False):
return get_node_last_lineno(node.body[-1])
# Not a compound statement
return node.lineno
def is_postponed_evaluation_enabled(node: astroid.node_classes.NodeNG) -> bool:
"""Check if the postponed evaluation of annotations is enabled"""
name = "annotations"
module = node.root()
stmt = module.locals.get(name)
return (
stmt
and isinstance(stmt[0], astroid.ImportFrom)
and stmt[0].modname == "__future__"
)
def is_subclass_of(child: astroid.ClassDef, parent: astroid.ClassDef) -> bool:
"""
Check if first node is a subclass of second node.
:param child: Node to check for subclass.
:param parent: Node to check for superclass.
:returns: True if child is derived from parent. False otherwise.
"""
if not all(isinstance(node, astroid.ClassDef) for node in (child, parent)):
return False
for ancestor in child.ancestors():
try:
if helpers.is_subtype(ancestor, parent):
return True
except _NonDeducibleTypeHierarchy:
continue
return False
@lru_cache(maxsize=1024)
def is_overload_stub(node: astroid.node_classes.NodeNG) -> bool:
"""Check if a node if is a function stub decorated with typing.overload.
:param node: Node to check.
:returns: True if node is an overload function stub. False otherwise.
"""
decorators = getattr(node, "decorators", None)
return bool(decorators and decorated_with(node, ["typing.overload", "overload"]))
def is_protocol_class(cls: astroid.node_classes.NodeNG) -> bool:
"""Check if the given node represents a protocol class
:param cls: The node to check
:returns: True if the node is a typing protocol class, false otherwise.
"""
if not isinstance(cls, astroid.ClassDef):
return False
# Use .ancestors() since not all protocol classes can have
# their mro deduced.
return any(parent.qname() in TYPING_PROTOCOLS for parent in cls.ancestors())
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