Source code for astroid.exceptions

# Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
# For details: https://github.com/pylint-dev/astroid/blob/main/LICENSE
# Copyright (c) https://github.com/pylint-dev/astroid/blob/main/CONTRIBUTORS.txt

"""This module contains exceptions used in the astroid library."""

from __future__ import annotations

from collections.abc import Iterable, Iterator
from typing import TYPE_CHECKING, Any

from astroid.typing import InferenceResult, SuccessfulInferenceResult

if TYPE_CHECKING:
    from astroid import arguments, bases, nodes, objects
    from astroid.context import InferenceContext

__all__ = (
    "AstroidBuildingError",
    "AstroidError",
    "AstroidImportError",
    "AstroidIndexError",
    "AstroidSyntaxError",
    "AstroidTypeError",
    "AstroidValueError",
    "AttributeInferenceError",
    "DuplicateBasesError",
    "InconsistentMroError",
    "InferenceError",
    "InferenceOverwriteError",
    "MroError",
    "NameInferenceError",
    "NoDefault",
    "NotFoundError",
    "ParentMissingError",
    "ResolveError",
    "StatementMissing",
    "SuperArgumentTypeError",
    "SuperError",
    "TooManyLevelsError",
    "UnresolvableName",
    "UseInferenceDefault",
)


[docs] class AstroidError(Exception): """Base exception class for all astroid related exceptions. AstroidError and its subclasses are structured, intended to hold objects representing state when the exception is thrown. Field values are passed to the constructor as keyword-only arguments. Each subclass has its own set of standard fields, but use your best judgment to decide whether a specific exception instance needs more or fewer fields for debugging. Field values may be used to lazily generate the error message: self.message.format() will be called with the field names and values supplied as keyword arguments. """ def __init__(self, message: str = "", **kws: Any) -> None: super().__init__(message) self.message = message for key, value in kws.items(): setattr(self, key, value) def __str__(self) -> str: return self.message.format(**vars(self))
[docs] class AstroidBuildingError(AstroidError): """Exception class when we are unable to build an astroid representation. Standard attributes: modname: Name of the module that AST construction failed for. error: Exception raised during construction. """ def __init__( self, message: str = "Failed to import module {modname}.", modname: str | None = None, error: Exception | None = None, source: str | None = None, path: str | None = None, cls: type | None = None, class_repr: str | None = None, **kws: Any, ) -> None: self.modname = modname self.error = error self.source = source self.path = path self.cls = cls self.class_repr = class_repr super().__init__(message, **kws)
[docs] class AstroidImportError(AstroidBuildingError): """Exception class used when a module can't be imported by astroid."""
[docs] class TooManyLevelsError(AstroidImportError): """Exception class which is raised when a relative import was beyond the top-level. Standard attributes: level: The level which was attempted. name: the name of the module on which the relative import was attempted. """ def __init__( self, message: str = "Relative import with too many levels " "({level}) for module {name!r}", level: int | None = None, name: str | None = None, **kws: Any, ) -> None: self.level = level self.name = name super().__init__(message, **kws)
[docs] class AstroidSyntaxError(AstroidBuildingError): """Exception class used when a module can't be parsed.""" def __init__( self, message: str, modname: str | None, error: Exception, path: str | None, source: str | None = None, ) -> None: super().__init__(message, modname, error, source, path)
[docs] class NoDefault(AstroidError): """Raised by function's `default_value` method when an argument has no default value. Standard attributes: func: Function node. name: Name of argument without a default. """ def __init__( self, message: str = "{func!r} has no default for {name!r}.", func: nodes.FunctionDef | None = None, name: str | None = None, **kws: Any, ) -> None: self.func = func self.name = name super().__init__(message, **kws)
[docs] class ResolveError(AstroidError): """Base class of astroid resolution/inference error. ResolveError is not intended to be raised. Standard attributes: context: InferenceContext object. """ def __init__( self, message: str = "", context: InferenceContext | None = None, **kws: Any ) -> None: self.context = context super().__init__(message, **kws)
[docs] class MroError(ResolveError): """Error raised when there is a problem with method resolution of a class. Standard attributes: mros: A sequence of sequences containing ClassDef nodes. cls: ClassDef node whose MRO resolution failed. context: InferenceContext object. """ def __init__( self, message: str, mros: Iterable[Iterable[nodes.ClassDef]], cls: nodes.ClassDef, context: InferenceContext | None = None, **kws: Any, ) -> None: self.mros = mros self.cls = cls self.context = context super().__init__(message, **kws) def __str__(self) -> str: mro_names = ", ".join(f"({', '.join(b.name for b in m)})" for m in self.mros) return self.message.format(mros=mro_names, cls=self.cls)
[docs] class DuplicateBasesError(MroError): """Error raised when there are duplicate bases in the same class bases."""
[docs] class InconsistentMroError(MroError): """Error raised when a class's MRO is inconsistent."""
[docs] class SuperError(ResolveError): """Error raised when there is a problem with a *super* call. Standard attributes: *super_*: The Super instance that raised the exception. context: InferenceContext object. """ def __init__(self, message: str, super_: objects.Super, **kws: Any) -> None: self.super_ = super_ super().__init__(message, **kws) def __str__(self) -> str: return self.message.format(**vars(self.super_))
[docs] class InferenceError(ResolveError): # pylint: disable=too-many-instance-attributes """Raised when we are unable to infer a node. Standard attributes: node: The node inference was called on. context: InferenceContext object. """ def __init__( # pylint: disable=too-many-arguments, too-many-positional-arguments self, message: str = "Inference failed for {node!r}.", node: InferenceResult | None = None, context: InferenceContext | None = None, target: InferenceResult | None = None, targets: InferenceResult | None = None, attribute: str | None = None, unknown: InferenceResult | None = None, assign_path: list[int] | None = None, caller: SuccessfulInferenceResult | None = None, stmts: Iterator[InferenceResult] | None = None, frame: InferenceResult | None = None, call_site: arguments.CallSite | None = None, func: InferenceResult | None = None, arg: str | None = None, positional_arguments: list | None = None, unpacked_args: list | None = None, keyword_arguments: dict | None = None, unpacked_kwargs: dict | None = None, **kws: Any, ) -> None: self.node = node self.context = context self.target = target self.targets = targets self.attribute = attribute self.unknown = unknown self.assign_path = assign_path self.caller = caller self.stmts = stmts self.frame = frame self.call_site = call_site self.func = func self.arg = arg self.positional_arguments = positional_arguments self.unpacked_args = unpacked_args self.keyword_arguments = keyword_arguments self.unpacked_kwargs = unpacked_kwargs super().__init__(message, **kws)
# Why does this inherit from InferenceError rather than ResolveError? # Changing it causes some inference tests to fail.
[docs] class NameInferenceError(InferenceError): """Raised when a name lookup fails, corresponds to NameError. Standard attributes: name: The name for which lookup failed, as a string. scope: The node representing the scope in which the lookup occurred. context: InferenceContext object. """ def __init__( self, message: str = "{name!r} not found in {scope!r}.", name: str | None = None, scope: nodes.LocalsDictNodeNG | None = None, context: InferenceContext | None = None, **kws: Any, ) -> None: self.name = name self.scope = scope self.context = context super().__init__(message, **kws)
[docs] class AttributeInferenceError(ResolveError): """Raised when an attribute lookup fails, corresponds to AttributeError. Standard attributes: target: The node for which lookup failed. attribute: The attribute for which lookup failed, as a string. context: InferenceContext object. """ def __init__( self, message: str = "{attribute!r} not found on {target!r}.", attribute: str = "", target: nodes.NodeNG | bases.BaseInstance | None = None, context: InferenceContext | None = None, mros: list[nodes.ClassDef] | None = None, super_: nodes.ClassDef | None = None, cls: nodes.ClassDef | None = None, **kws: Any, ) -> None: self.attribute = attribute self.target = target self.context = context self.mros = mros self.super_ = super_ self.cls = cls super().__init__(message, **kws)
[docs] class UseInferenceDefault(Exception): """Exception to be raised in custom inference function to indicate that it should go back to the default behaviour. """
class _NonDeducibleTypeHierarchy(Exception): """Raised when is_subtype / is_supertype can't deduce the relation between two types. """
[docs] class AstroidIndexError(AstroidError): """Raised when an Indexable / Mapping does not have an index / key.""" def __init__( self, message: str = "", node: nodes.NodeNG | bases.Instance | None = None, index: nodes.Subscript | None = None, context: InferenceContext | None = None, **kws: Any, ) -> None: self.node = node self.index = index self.context = context super().__init__(message, **kws)
[docs] class AstroidTypeError(AstroidError): """Raised when a TypeError would be expected in Python code.""" def __init__( self, message: str = "", node: nodes.NodeNG | bases.Instance | None = None, index: nodes.Subscript | None = None, context: InferenceContext | None = None, **kws: Any, ) -> None: self.node = node self.index = index self.context = context super().__init__(message, **kws)
[docs] class AstroidValueError(AstroidError): """Raised when a ValueError would be expected in Python code."""
[docs] class InferenceOverwriteError(AstroidError): """Raised when an inference tip is overwritten. Currently only used for debugging. """
[docs] class ParentMissingError(AstroidError): """Raised when a node which is expected to have a parent attribute is missing one. Standard attributes: target: The node for which the parent lookup failed. """ def __init__(self, target: nodes.NodeNG) -> None: self.target = target super().__init__(message=f"Parent not found on {target!r}.")
[docs] class StatementMissing(ParentMissingError): """Raised when a call to node.statement() does not return a node. This is because a node in the chain does not have a parent attribute and therefore does not return a node for statement(). Standard attributes: target: The node for which the parent lookup failed. """ def __init__(self, target: nodes.NodeNG) -> None: super(ParentMissingError, self).__init__( message=f"Statement not found on {target!r}" )
SuperArgumentTypeError = SuperError UnresolvableName = NameInferenceError NotFoundError = AttributeInferenceError