""" Main module. Implement the central Checker class. Also, it models the Bindings and Scopes. """ import __future__ import builtins import ast import bisect import collections import contextlib import doctest import functools import os import re import string import sys import tokenize from pyflakes import messages PY38_PLUS = sys.version_info >= (3, 8) PYPY = hasattr(sys, 'pypy_version_info') builtin_vars = dir(builtins) parse_format_string = string.Formatter().parse def getAlternatives(n): if isinstance(n, ast.If): return [n.body] if isinstance(n, ast.Try): return [n.body + n.orelse] + [[hdl] for hdl in n.handlers] FOR_TYPES = (ast.For, ast.AsyncFor) if PY38_PLUS: def _is_singleton(node): # type: (ast.AST) -> bool return ( isinstance(node, ast.Constant) and isinstance(node.value, (bool, type(Ellipsis), type(None))) ) else: def _is_singleton(node): # type: (ast.AST) -> bool return isinstance(node, (ast.NameConstant, ast.Ellipsis)) def _is_tuple_constant(node): # type: (ast.AST) -> bool return ( isinstance(node, ast.Tuple) and all(_is_constant(elt) for elt in node.elts) ) if PY38_PLUS: def _is_constant(node): return isinstance(node, ast.Constant) or _is_tuple_constant(node) else: def _is_constant(node): return ( isinstance(node, (ast.Str, ast.Num, ast.Bytes)) or _is_singleton(node) or _is_tuple_constant(node) ) def _is_const_non_singleton(node): # type: (ast.AST) -> bool return _is_constant(node) and not _is_singleton(node) def _is_name_or_attr(node, name): # type: (ast.AST, str) -> bool return ( (isinstance(node, ast.Name) and node.id == name) or (isinstance(node, ast.Attribute) and node.attr == name) ) # https://github.com/python/typed_ast/blob/1.4.0/ast27/Parser/tokenizer.c#L102-L104 TYPE_COMMENT_RE = re.compile(r'^#\s*type:\s*') # https://github.com/python/typed_ast/blob/1.4.0/ast27/Parser/tokenizer.c#L1408-L1413 ASCII_NON_ALNUM = ''.join([chr(i) for i in range(128) if not chr(i).isalnum()]) TYPE_IGNORE_RE = re.compile( TYPE_COMMENT_RE.pattern + fr'ignore([{ASCII_NON_ALNUM}]|$)') # https://github.com/python/typed_ast/blob/1.4.0/ast27/Grammar/Grammar#L147 TYPE_FUNC_RE = re.compile(r'^(\(.*?\))\s*->\s*(.*)$') MAPPING_KEY_RE = re.compile(r'\(([^()]*)\)') CONVERSION_FLAG_RE = re.compile('[#0+ -]*') WIDTH_RE = re.compile(r'(?:\*|\d*)') PRECISION_RE = re.compile(r'(?:\.(?:\*|\d*))?') LENGTH_RE = re.compile('[hlL]?') # https://docs.python.org/3/library/stdtypes.html#old-string-formatting VALID_CONVERSIONS = frozenset('diouxXeEfFgGcrsa%') def _must_match(regex, string, pos): match = regex.match(string, pos) assert match is not None return match def parse_percent_format(s): """Parses the string component of a `'...' % ...` format call Copied from https://github.com/asottile/pyupgrade at v1.20.1 """ def _parse_inner(): string_start = 0 string_end = 0 in_fmt = False i = 0 while i < len(s): if not in_fmt: try: i = s.index('%', i) except ValueError: # no more % fields! yield s[string_start:], None return else: string_end = i i += 1 in_fmt = True else: key_match = MAPPING_KEY_RE.match(s, i) if key_match: key = key_match.group(1) i = key_match.end() else: key = None conversion_flag_match = _must_match(CONVERSION_FLAG_RE, s, i) conversion_flag = conversion_flag_match.group() or None i = conversion_flag_match.end() width_match = _must_match(WIDTH_RE, s, i) width = width_match.group() or None i = width_match.end() precision_match = _must_match(PRECISION_RE, s, i) precision = precision_match.group() or None i = precision_match.end() # length modifier is ignored i = _must_match(LENGTH_RE, s, i).end() try: conversion = s[i] except IndexError: raise ValueError('end-of-string while parsing format') i += 1 fmt = (key, conversion_flag, width, precision, conversion) yield s[string_start:string_end], fmt in_fmt = False string_start = i if in_fmt: raise ValueError('end-of-string while parsing format') return tuple(_parse_inner()) class _FieldsOrder(dict): """Fix order of AST node fields.""" def _get_fields(self, node_class): # handle iter before target, and generators before element fields = node_class._fields if 'iter' in fields: key_first = 'iter'.find elif 'generators' in fields: key_first = 'generators'.find else: key_first = 'value'.find return tuple(sorted(fields, key=key_first, reverse=True)) def __missing__(self, node_class): self[node_class] = fields = self._get_fields(node_class) return fields def counter(items): """ Simplest required implementation of collections.Counter. Required as 2.6 does not have Counter in collections. """ results = {} for item in items: results[item] = results.get(item, 0) + 1 return results def iter_child_nodes(node, omit=None, _fields_order=_FieldsOrder()): """ Yield all direct child nodes of *node*, that is, all fields that are nodes and all items of fields that are lists of nodes. :param node: AST node to be iterated upon :param omit: String or tuple of strings denoting the attributes of the node to be omitted from further parsing :param _fields_order: Order of AST node fields """ for name in _fields_order[node.__class__]: if omit and name in omit: continue field = getattr(node, name, None) if isinstance(field, ast.AST): yield field elif isinstance(field, list): for item in field: if isinstance(item, ast.AST): yield item def convert_to_value(item): if isinstance(item, ast.Str): return item.s elif hasattr(ast, 'Bytes') and isinstance(item, ast.Bytes): return item.s elif isinstance(item, ast.Tuple): return tuple(convert_to_value(i) for i in item.elts) elif isinstance(item, ast.Num): return item.n elif isinstance(item, ast.Name): result = VariableKey(item=item) constants_lookup = { 'True': True, 'False': False, 'None': None, } return constants_lookup.get( result.name, result, ) elif isinstance(item, ast.NameConstant): return item.value else: return UnhandledKeyType() def is_notimplemented_name_node(node): return isinstance(node, ast.Name) and getNodeName(node) == 'NotImplemented' class Binding: """ Represents the binding of a value to a name. The checker uses this to keep track of which names have been bound and which names have not. See L{Assignment} for a special type of binding that is checked with stricter rules. @ivar used: pair of (L{Scope}, node) indicating the scope and the node that this binding was last used. """ def __init__(self, name, source): self.name = name self.source = source self.used = False def __str__(self): return self.name def __repr__(self): return '<{} object {!r} from line {!r} at 0x{:x}>'.format( self.__class__.__name__, self.name, self.source.lineno, id(self), ) def redefines(self, other): return isinstance(other, Definition) and self.name == other.name class Definition(Binding): """ A binding that defines a function or a class. """ class Builtin(Definition): """A definition created for all Python builtins.""" def __init__(self, name): super().__init__(name, None) def __repr__(self): return '<{} object {!r} at 0x{:x}>'.format( self.__class__.__name__, self.name, id(self) ) class UnhandledKeyType: """ A dictionary key of a type that we cannot or do not check for duplicates. """ class VariableKey: """ A dictionary key which is a variable. @ivar item: The variable AST object. """ def __init__(self, item): self.name = item.id def __eq__(self, compare): return ( compare.__class__ == self.__class__ and compare.name == self.name ) def __hash__(self): return hash(self.name) class Importation(Definition): """ A binding created by an import statement. @ivar fullName: The complete name given to the import statement, possibly including multiple dotted components. @type fullName: C{str} """ def __init__(self, name, source, full_name=None): self.fullName = full_name or name self.redefined = [] super().__init__(name, source) def redefines(self, other): if isinstance(other, SubmoduleImportation): # See note in SubmoduleImportation about RedefinedWhileUnused return self.fullName == other.fullName return isinstance(other, Definition) and self.name == other.name def _has_alias(self): """Return whether importation needs an as clause.""" return not self.fullName.split('.')[-1] == self.name @property def source_statement(self): """Generate a source statement equivalent to the import.""" if self._has_alias(): return f'import {self.fullName} as {self.name}' else: return 'import %s' % self.fullName def __str__(self): """Return import full name with alias.""" if self._has_alias(): return self.fullName + ' as ' + self.name else: return self.fullName class SubmoduleImportation(Importation): """ A binding created by a submodule import statement. A submodule import is a special case where the root module is implicitly imported, without an 'as' clause, and the submodule is also imported. Python does not restrict which attributes of the root module may be used. This class is only used when the submodule import is without an 'as' clause. pyflakes handles this case by registering the root module name in the scope, allowing any attribute of the root module to be accessed. RedefinedWhileUnused is suppressed in `redefines` unless the submodule name is also the same, to avoid false positives. """ def __init__(self, name, source): # A dot should only appear in the name when it is a submodule import assert '.' in name and (not source or isinstance(source, ast.Import)) package_name = name.split('.')[0] super().__init__(package_name, source) self.fullName = name def redefines(self, other): if isinstance(other, Importation): return self.fullName == other.fullName return super().redefines(other) def __str__(self): return self.fullName @property def source_statement(self): return 'import ' + self.fullName class ImportationFrom(Importation): def __init__(self, name, source, module, real_name=None): self.module = module self.real_name = real_name or name if module.endswith('.'): full_name = module + self.real_name else: full_name = module + '.' + self.real_name super().__init__(name, source, full_name) def __str__(self): """Return import full name with alias.""" if self.real_name != self.name: return self.fullName + ' as ' + self.name else: return self.fullName @property def source_statement(self): if self.real_name != self.name: return f'from {self.module} import {self.real_name} as {self.name}' else: return f'from {self.module} import {self.name}' class StarImportation(Importation): """A binding created by a 'from x import *' statement.""" def __init__(self, name, source): super().__init__('*', source) # Each star importation needs a unique name, and # may not be the module name otherwise it will be deemed imported self.name = name + '.*' self.fullName = name @property def source_statement(self): return 'from ' + self.fullName + ' import *' def __str__(self): # When the module ends with a ., avoid the ambiguous '..*' if self.fullName.endswith('.'): return self.source_statement else: return self.name class FutureImportation(ImportationFrom): """ A binding created by a from `__future__` import statement. `__future__` imports are implicitly used. """ def __init__(self, name, source, scope): super().__init__(name, source, '__future__') self.used = (scope, source) class Argument(Binding): """ Represents binding a name as an argument. """ class Assignment(Binding): """ Represents binding a name with an explicit assignment. The checker will raise warnings for any Assignment that isn't used. Also, the checker does not consider assignments in tuple/list unpacking to be Assignments, rather it treats them as simple Bindings. """ class NamedExprAssignment(Assignment): """ Represents binding a name with an assignment expression. """ class Annotation(Binding): """ Represents binding a name to a type without an associated value. As long as this name is not assigned a value in another binding, it is considered undefined for most purposes. One notable exception is using the name as a type annotation. """ def redefines(self, other): """An Annotation doesn't define any name, so it cannot redefine one.""" return False class FunctionDefinition(Definition): pass class ClassDefinition(Definition): pass class ExportBinding(Binding): """ A binding created by an C{__all__} assignment. If the names in the list can be determined statically, they will be treated as names for export and additional checking applied to them. The only recognized C{__all__} assignment via list/tuple concatenation is in the following format: __all__ = ['a'] + ['b'] + ['c'] Names which are imported and not otherwise used but appear in the value of C{__all__} will not have an unused import warning reported for them. """ def __init__(self, name, source, scope): if '__all__' in scope and isinstance(source, ast.AugAssign): self.names = list(scope['__all__'].names) else: self.names = [] def _add_to_names(container): for node in container.elts: if isinstance(node, ast.Str): self.names.append(node.s) if isinstance(source.value, (ast.List, ast.Tuple)): _add_to_names(source.value) # If concatenating lists or tuples elif isinstance(source.value, ast.BinOp): currentValue = source.value while isinstance(currentValue.right, (ast.List, ast.Tuple)): left = currentValue.left right = currentValue.right _add_to_names(right) # If more lists are being added if isinstance(left, ast.BinOp): currentValue = left # If just two lists are being added elif isinstance(left, (ast.List, ast.Tuple)): _add_to_names(left) # All lists accounted for - done break # If not list concatenation else: break super().__init__(name, source) class Scope(dict): importStarred = False # set to True when import * is found def __repr__(self): scope_cls = self.__class__.__name__ return f'<{scope_cls} at 0x{id(self):x} {dict.__repr__(self)}>' class ClassScope(Scope): pass class FunctionScope(Scope): """ I represent a name scope for a function. @ivar globals: Names declared 'global' in this function. """ usesLocals = False alwaysUsed = {'__tracebackhide__', '__traceback_info__', '__traceback_supplement__'} def __init__(self): super().__init__() # Simplify: manage the special locals as globals self.globals = self.alwaysUsed.copy() self.returnValue = None # First non-empty return self.isGenerator = False # Detect a generator def unusedAssignments(self): """ Return a generator for the assignments which have not been used. """ for name, binding in self.items(): if (not binding.used and name != '_' and # see issue #202 name not in self.globals and not self.usesLocals and isinstance(binding, Assignment)): yield name, binding class GeneratorScope(Scope): pass class ModuleScope(Scope): """Scope for a module.""" _futures_allowed = True _annotations_future_enabled = False class DoctestScope(ModuleScope): """Scope for a doctest.""" class DummyNode: """Used in place of an `ast.AST` to set error message positions""" def __init__(self, lineno, col_offset): self.lineno = lineno self.col_offset = col_offset class DetectClassScopedMagic: names = dir() # Globally defined names which are not attributes of the builtins module, or # are only present on some platforms. _MAGIC_GLOBALS = ['__file__', '__builtins__', '__annotations__', 'WindowsError'] def getNodeName(node): # Returns node.id, or node.name, or None if hasattr(node, 'id'): # One of the many nodes with an id return node.id if hasattr(node, 'name'): # an ExceptHandler node return node.name if hasattr(node, 'rest'): # a MatchMapping node return node.rest TYPING_MODULES = frozenset(('typing', 'typing_extensions')) def _is_typing_helper(node, is_name_match_fn, scope_stack): """ Internal helper to determine whether or not something is a member of a typing module. This is used as part of working out whether we are within a type annotation context. Note: you probably don't want to use this function directly. Instead see the utils below which wrap it (`_is_typing` and `_is_any_typing_member`). """ def _bare_name_is_attr(name): for scope in reversed(scope_stack): if name in scope: return ( isinstance(scope[name], ImportationFrom) and scope[name].module in TYPING_MODULES and is_name_match_fn(scope[name].real_name) ) return False def _module_scope_is_typing(name): for scope in reversed(scope_stack): if name in scope: return ( isinstance(scope[name], Importation) and scope[name].fullName in TYPING_MODULES ) return False return ( ( isinstance(node, ast.Name) and _bare_name_is_attr(node.id) ) or ( isinstance(node, ast.Attribute) and isinstance(node.value, ast.Name) and _module_scope_is_typing(node.value.id) and is_name_match_fn(node.attr) ) ) def _is_typing(node, typing_attr, scope_stack): """ Determine whether `node` represents the member of a typing module specified by `typing_attr`. This is used as part of working out whether we are within a type annotation context. """ return _is_typing_helper(node, lambda x: x == typing_attr, scope_stack) def _is_any_typing_member(node, scope_stack): """ Determine whether `node` represents any member of a typing module. This is used as part of working out whether we are within a type annotation context. """ return _is_typing_helper(node, lambda x: True, scope_stack) def is_typing_overload(value, scope_stack): return ( isinstance(value.source, (ast.FunctionDef, ast.AsyncFunctionDef)) and any( _is_typing(dec, 'overload', scope_stack) for dec in value.source.decorator_list ) ) class AnnotationState: NONE = 0 STRING = 1 BARE = 2 def in_annotation(func): @functools.wraps(func) def in_annotation_func(self, *args, **kwargs): with self._enter_annotation(): return func(self, *args, **kwargs) return in_annotation_func def in_string_annotation(func): @functools.wraps(func) def in_annotation_func(self, *args, **kwargs): with self._enter_annotation(AnnotationState.STRING): return func(self, *args, **kwargs) return in_annotation_func def make_tokens(code): # PY3: tokenize.tokenize requires readline of bytes if not isinstance(code, bytes): code = code.encode('UTF-8') lines = iter(code.splitlines(True)) # next(lines, b'') is to prevent an error in pypy3 return tuple(tokenize.tokenize(lambda: next(lines, b''))) class _TypeableVisitor(ast.NodeVisitor): """Collect the line number and nodes which are deemed typeable by PEP 484 https://www.python.org/dev/peps/pep-0484/#type-comments """ def __init__(self): self.typeable_lines = [] self.typeable_nodes = {} def _typeable(self, node): # if there is more than one typeable thing on a line last one wins self.typeable_lines.append(node.lineno) self.typeable_nodes[node.lineno] = node self.generic_visit(node) visit_Assign = visit_For = visit_FunctionDef = visit_With = _typeable visit_AsyncFor = visit_AsyncFunctionDef = visit_AsyncWith = _typeable def _collect_type_comments(tree, tokens): visitor = _TypeableVisitor() visitor.visit(tree) type_comments = collections.defaultdict(list) for tp, text, start, _, _ in tokens: if ( tp != tokenize.COMMENT or # skip non comments not TYPE_COMMENT_RE.match(text) or # skip non-type comments TYPE_IGNORE_RE.match(text) # skip ignores ): continue # search for the typeable node at or before the line number of the # type comment. # if the bisection insertion point is before any nodes this is an # invalid type comment which is ignored. lineno, _ = start idx = bisect.bisect_right(visitor.typeable_lines, lineno) if idx == 0: continue node = visitor.typeable_nodes[visitor.typeable_lines[idx - 1]] type_comments[node].append((start, text)) return type_comments class Checker: """ I check the cleanliness and sanity of Python code. @ivar _deferredFunctions: Tracking list used by L{deferFunction}. Elements of the list are two-tuples. The first element is the callable passed to L{deferFunction}. The second element is a copy of the scope stack at the time L{deferFunction} was called. @ivar _deferredAssignments: Similar to C{_deferredFunctions}, but for callables which are deferred assignment checks. """ _ast_node_scope = { ast.Module: ModuleScope, ast.ClassDef: ClassScope, ast.FunctionDef: FunctionScope, ast.AsyncFunctionDef: FunctionScope, ast.Lambda: FunctionScope, ast.ListComp: GeneratorScope, ast.SetComp: GeneratorScope, ast.GeneratorExp: GeneratorScope, ast.DictComp: GeneratorScope, } nodeDepth = 0 offset = None _in_annotation = AnnotationState.NONE _in_deferred = False builtIns = set(builtin_vars).union(_MAGIC_GLOBALS) _customBuiltIns = os.environ.get('PYFLAKES_BUILTINS') if _customBuiltIns: builtIns.update(_customBuiltIns.split(',')) del _customBuiltIns # TODO: file_tokens= is required to perform checks on type comments, # eventually make this a required positional argument. For now it # is defaulted to `()` for api compatibility. def __init__(self, tree, filename='(none)', builtins=None, withDoctest='PYFLAKES_DOCTEST' in os.environ, file_tokens=()): self._nodeHandlers = {} self._deferredFunctions = [] self._deferredAssignments = [] self.deadScopes = [] self.messages = [] self.filename = filename if builtins: self.builtIns = self.builtIns.union(builtins) self.withDoctest = withDoctest try: self.scopeStack = [Checker._ast_node_scope[type(tree)]()] except KeyError: raise RuntimeError('No scope implemented for the node %r' % tree) self.exceptHandlers = [()] self.root = tree self._type_comments = _collect_type_comments(tree, file_tokens) for builtin in self.builtIns: self.addBinding(None, Builtin(builtin)) self.handleChildren(tree) self._in_deferred = True self.runDeferred(self._deferredFunctions) # Set _deferredFunctions to None so that deferFunction will fail # noisily if called after we've run through the deferred functions. self._deferredFunctions = None self.runDeferred(self._deferredAssignments) # Set _deferredAssignments to None so that deferAssignment will fail # noisily if called after we've run through the deferred assignments. self._deferredAssignments = None del self.scopeStack[1:] self.popScope() self.checkDeadScopes() def deferFunction(self, callable): """ Schedule a function handler to be called just before completion. This is used for handling function bodies, which must be deferred because code later in the file might modify the global scope. When `callable` is called, the scope at the time this is called will be restored, however it will contain any new bindings added to it. """ self._deferredFunctions.append((callable, self.scopeStack[:], self.offset)) def deferAssignment(self, callable): """ Schedule an assignment handler to be called just after deferred function handlers. """ self._deferredAssignments.append((callable, self.scopeStack[:], self.offset)) def runDeferred(self, deferred): """ Run the callables in C{deferred} using their associated scope stack. """ for handler, scope, offset in deferred: self.scopeStack = scope self.offset = offset handler() def _in_doctest(self): return (len(self.scopeStack) >= 2 and isinstance(self.scopeStack[1], DoctestScope)) @property def futuresAllowed(self): if not all(isinstance(scope, ModuleScope) for scope in self.scopeStack): return False return self.scope._futures_allowed @futuresAllowed.setter def futuresAllowed(self, value): assert value is False if isinstance(self.scope, ModuleScope): self.scope._futures_allowed = False @property def annotationsFutureEnabled(self): scope = self.scopeStack[0] if not isinstance(scope, ModuleScope): return False return scope._annotations_future_enabled @annotationsFutureEnabled.setter def annotationsFutureEnabled(self, value): assert value is True assert isinstance(self.scope, ModuleScope) self.scope._annotations_future_enabled = True @property def scope(self): return self.scopeStack[-1] def popScope(self): self.deadScopes.append(self.scopeStack.pop()) def checkDeadScopes(self): """ Look at scopes which have been fully examined and report names in them which were imported but unused. """ for scope in self.deadScopes: # imports in classes are public members if isinstance(scope, ClassScope): continue all_binding = scope.get('__all__') if all_binding and not isinstance(all_binding, ExportBinding): all_binding = None if all_binding: all_names = set(all_binding.names) undefined = [ name for name in all_binding.names if name not in scope ] else: all_names = undefined = [] if undefined: if not scope.importStarred and \ os.path.basename(self.filename) != '__init__.py': # Look for possible mistakes in the export list for name in undefined: self.report(messages.UndefinedExport, scope['__all__'].source, name) # mark all import '*' as used by the undefined in __all__ if scope.importStarred: from_list = [] for binding in scope.values(): if isinstance(binding, StarImportation): binding.used = all_binding from_list.append(binding.fullName) # report * usage, with a list of possible sources from_list = ', '.join(sorted(from_list)) for name in undefined: self.report(messages.ImportStarUsage, scope['__all__'].source, name, from_list) # Look for imported names that aren't used. for value in scope.values(): if isinstance(value, Importation): used = value.used or value.name in all_names if not used: messg = messages.UnusedImport self.report(messg, value.source, str(value)) for node in value.redefined: if isinstance(self.getParent(node), FOR_TYPES): messg = messages.ImportShadowedByLoopVar elif used: continue else: messg = messages.RedefinedWhileUnused self.report(messg, node, value.name, value.source) def pushScope(self, scopeClass=FunctionScope): self.scopeStack.append(scopeClass()) def report(self, messageClass, *args, **kwargs): self.messages.append(messageClass(self.filename, *args, **kwargs)) def getParent(self, node): # Lookup the first parent which is not Tuple, List or Starred while True: node = node._pyflakes_parent if not hasattr(node, 'elts') and not hasattr(node, 'ctx'): return node def getCommonAncestor(self, lnode, rnode, stop): if ( stop in (lnode, rnode) or not ( hasattr(lnode, '_pyflakes_parent') and hasattr(rnode, '_pyflakes_parent') ) ): return None if lnode is rnode: return lnode if (lnode._pyflakes_depth > rnode._pyflakes_depth): return self.getCommonAncestor(lnode._pyflakes_parent, rnode, stop) if (lnode._pyflakes_depth < rnode._pyflakes_depth): return self.getCommonAncestor(lnode, rnode._pyflakes_parent, stop) return self.getCommonAncestor( lnode._pyflakes_parent, rnode._pyflakes_parent, stop, ) def descendantOf(self, node, ancestors, stop): for a in ancestors: if self.getCommonAncestor(node, a, stop): return True return False def _getAncestor(self, node, ancestor_type): parent = node while True: if parent is self.root: return None parent = self.getParent(parent) if isinstance(parent, ancestor_type): return parent def getScopeNode(self, node): return self._getAncestor(node, tuple(Checker._ast_node_scope.keys())) def differentForks(self, lnode, rnode): """True, if lnode and rnode are located on different forks of IF/TRY""" ancestor = self.getCommonAncestor(lnode, rnode, self.root) parts = getAlternatives(ancestor) if parts: for items in parts: if self.descendantOf(lnode, items, ancestor) ^ \ self.descendantOf(rnode, items, ancestor): return True return False def addBinding(self, node, value): """ Called when a binding is altered. - `node` is the statement responsible for the change - `value` is the new value, a Binding instance """ # assert value.source in (node, node._pyflakes_parent): for scope in self.scopeStack[::-1]: if value.name in scope: break existing = scope.get(value.name) if (existing and not isinstance(existing, Builtin) and not self.differentForks(node, existing.source)): parent_stmt = self.getParent(value.source) if isinstance(existing, Importation) and isinstance(parent_stmt, FOR_TYPES): self.report(messages.ImportShadowedByLoopVar, node, value.name, existing.source) elif scope is self.scope: if ( (not existing.used and value.redefines(existing)) and (value.name != '_' or isinstance(existing, Importation)) and not is_typing_overload(existing, self.scopeStack) ): self.report(messages.RedefinedWhileUnused, node, value.name, existing.source) elif isinstance(existing, Importation) and value.redefines(existing): existing.redefined.append(node) if value.name in self.scope: # then assume the rebound name is used as a global or within a loop value.used = self.scope[value.name].used # don't treat annotations as assignments if there is an existing value # in scope if value.name not in self.scope or not isinstance(value, Annotation): cur_scope_pos = -1 # As per PEP 572, use scope in which outermost generator is defined while ( isinstance(value, NamedExprAssignment) and isinstance(self.scopeStack[cur_scope_pos], GeneratorScope) ): cur_scope_pos -= 1 self.scopeStack[cur_scope_pos][value.name] = value def _unknown_handler(self, node): # this environment variable configures whether to error on unknown # ast types. # # this is silent by default but the error is enabled for the pyflakes # testsuite. # # this allows new syntax to be added to python without *requiring* # changes from the pyflakes side. but will still produce an error # in the pyflakes testsuite (so more specific handling can be added if # needed). if os.environ.get('PYFLAKES_ERROR_UNKNOWN'): raise NotImplementedError(f'Unexpected type: {type(node)}') else: self.handleChildren(node) def getNodeHandler(self, node_class): try: return self._nodeHandlers[node_class] except KeyError: nodeType = node_class.__name__.upper() self._nodeHandlers[node_class] = handler = getattr( self, nodeType, self._unknown_handler, ) return handler def handleNodeLoad(self, node): name = getNodeName(node) if not name: return in_generators = None importStarred = None # try enclosing function scopes and global scope for scope in self.scopeStack[-1::-1]: if isinstance(scope, ClassScope): if name == '__class__': return elif in_generators is False: # only generators used in a class scope can access the # names of the class. this is skipped during the first # iteration continue binding = scope.get(name, None) if isinstance(binding, Annotation) and not self._in_postponed_annotation: continue if name == 'print' and isinstance(binding, Builtin): parent = self.getParent(node) if (isinstance(parent, ast.BinOp) and isinstance(parent.op, ast.RShift)): self.report(messages.InvalidPrintSyntax, node) try: scope[name].used = (self.scope, node) # if the name of SubImportation is same as # alias of other Importation and the alias # is used, SubImportation also should be marked as used. n = scope[name] if isinstance(n, Importation) and n._has_alias(): try: scope[n.fullName].used = (self.scope, node) except KeyError: pass except KeyError: pass else: return importStarred = importStarred or scope.importStarred if in_generators is not False: in_generators = isinstance(scope, GeneratorScope) if importStarred: from_list = [] for scope in self.scopeStack[-1::-1]: for binding in scope.values(): if isinstance(binding, StarImportation): # mark '*' imports as used for each scope binding.used = (self.scope, node) from_list.append(binding.fullName) # report * usage, with a list of possible sources from_list = ', '.join(sorted(from_list)) self.report(messages.ImportStarUsage, node, name, from_list) return if name == '__path__' and os.path.basename(self.filename) == '__init__.py': # the special name __path__ is valid only in packages return if name in DetectClassScopedMagic.names and isinstance(self.scope, ClassScope): return # protected with a NameError handler? if 'NameError' not in self.exceptHandlers[-1]: self.report(messages.UndefinedName, node, name) def handleNodeStore(self, node): name = getNodeName(node) if not name: return # if the name hasn't already been defined in the current scope if isinstance(self.scope, FunctionScope) and name not in self.scope: # for each function or module scope above us for scope in self.scopeStack[:-1]: if not isinstance(scope, (FunctionScope, ModuleScope)): continue # if the name was defined in that scope, and the name has # been accessed already in the current scope, and hasn't # been declared global used = name in scope and scope[name].used if used and used[0] is self.scope and name not in self.scope.globals: # then it's probably a mistake self.report(messages.UndefinedLocal, scope[name].used[1], name, scope[name].source) break parent_stmt = self.getParent(node) if isinstance(parent_stmt, ast.AnnAssign) and parent_stmt.value is None: binding = Annotation(name, node) elif isinstance(parent_stmt, (FOR_TYPES, ast.comprehension)) or ( parent_stmt != node._pyflakes_parent and not self.isLiteralTupleUnpacking(parent_stmt)): binding = Binding(name, node) elif ( name == '__all__' and isinstance(self.scope, ModuleScope) and isinstance( node._pyflakes_parent, (ast.Assign, ast.AugAssign, ast.AnnAssign) ) ): binding = ExportBinding(name, node._pyflakes_parent, self.scope) elif PY38_PLUS and isinstance(parent_stmt, ast.NamedExpr): binding = NamedExprAssignment(name, node) else: binding = Assignment(name, node) self.addBinding(node, binding) def handleNodeDelete(self, node): def on_conditional_branch(): """ Return `True` if node is part of a conditional body. """ current = getattr(node, '_pyflakes_parent', None) while current: if isinstance(current, (ast.If, ast.While, ast.IfExp)): return True current = getattr(current, '_pyflakes_parent', None) return False name = getNodeName(node) if not name: return if on_conditional_branch(): # We cannot predict if this conditional branch is going to # be executed. return if isinstance(self.scope, FunctionScope) and name in self.scope.globals: self.scope.globals.remove(name) else: try: del self.scope[name] except KeyError: self.report(messages.UndefinedName, node, name) @contextlib.contextmanager def _enter_annotation(self, ann_type=AnnotationState.BARE): orig, self._in_annotation = self._in_annotation, ann_type try: yield finally: self._in_annotation = orig @property def _in_postponed_annotation(self): return ( self._in_annotation == AnnotationState.STRING or self.annotationsFutureEnabled ) def _handle_type_comments(self, node): for (lineno, col_offset), comment in self._type_comments.get(node, ()): comment = comment.split(':', 1)[1].strip() func_match = TYPE_FUNC_RE.match(comment) if func_match: parts = ( func_match.group(1).replace('*', ''), func_match.group(2).strip(), ) else: parts = (comment,) for part in parts: self.deferFunction(functools.partial( self.handleStringAnnotation, part, DummyNode(lineno, col_offset), lineno, col_offset, messages.CommentAnnotationSyntaxError, )) def handleChildren(self, tree, omit=None): self._handle_type_comments(tree) for node in iter_child_nodes(tree, omit=omit): self.handleNode(node, tree) def isLiteralTupleUnpacking(self, node): if isinstance(node, ast.Assign): for child in node.targets + [node.value]: if not hasattr(child, 'elts'): return False return True def isDocstring(self, node): """ Determine if the given node is a docstring, as long as it is at the correct place in the node tree. """ return isinstance(node, ast.Str) or (isinstance(node, ast.Expr) and isinstance(node.value, ast.Str)) def getDocstring(self, node): if isinstance(node, ast.Expr): node = node.value if not isinstance(node, ast.Str): return (None, None) if PYPY or PY38_PLUS: doctest_lineno = node.lineno - 1 else: # Computed incorrectly if the docstring has backslash doctest_lineno = node.lineno - node.s.count('\n') - 1 return (node.s, doctest_lineno) def handleNode(self, node, parent): if node is None: return if self.offset and getattr(node, 'lineno', None) is not None: node.lineno += self.offset[0] node.col_offset += self.offset[1] if self.futuresAllowed and not (isinstance(node, ast.ImportFrom) or self.isDocstring(node)): self.futuresAllowed = False self.nodeDepth += 1 node._pyflakes_depth = self.nodeDepth node._pyflakes_parent = parent try: handler = self.getNodeHandler(node.__class__) handler(node) finally: self.nodeDepth -= 1 _getDoctestExamples = doctest.DocTestParser().get_examples def handleDoctests(self, node): try: (docstring, node_lineno) = self.getDocstring(node.body[0]) examples = docstring and self._getDoctestExamples(docstring) except (ValueError, IndexError): # e.g. line 6 of the docstring for has inconsistent # leading whitespace: ... return if not examples: return # Place doctest in module scope saved_stack = self.scopeStack self.scopeStack = [self.scopeStack[0]] node_offset = self.offset or (0, 0) self.pushScope(DoctestScope) if '_' not in self.scopeStack[0]: self.addBinding(None, Builtin('_')) for example in examples: try: tree = ast.parse(example.source, "") except SyntaxError as e: position = (node_lineno + example.lineno + e.lineno, example.indent + 4 + (e.offset or 0)) self.report(messages.DoctestSyntaxError, node, position) else: self.offset = (node_offset[0] + node_lineno + example.lineno, node_offset[1] + example.indent + 4) self.handleChildren(tree) self.offset = node_offset self.popScope() self.scopeStack = saved_stack @in_string_annotation def handleStringAnnotation(self, s, node, ref_lineno, ref_col_offset, err): try: tree = ast.parse(s) except SyntaxError: self.report(err, node, s) return body = tree.body if len(body) != 1 or not isinstance(body[0], ast.Expr): self.report(err, node, s) return parsed_annotation = tree.body[0].value for descendant in ast.walk(parsed_annotation): if ( 'lineno' in descendant._attributes and 'col_offset' in descendant._attributes ): descendant.lineno = ref_lineno descendant.col_offset = ref_col_offset self.handleNode(parsed_annotation, node) @in_annotation def handleAnnotation(self, annotation, node): if isinstance(annotation, ast.Str): # Defer handling forward annotation. self.deferFunction(functools.partial( self.handleStringAnnotation, annotation.s, node, annotation.lineno, annotation.col_offset, messages.ForwardAnnotationSyntaxError, )) elif self.annotationsFutureEnabled: fn = in_annotation(Checker.handleNode) self.deferFunction(lambda: fn(self, annotation, node)) else: self.handleNode(annotation, node) def ignore(self, node): pass # "stmt" type nodes DELETE = FOR = ASYNCFOR = WHILE = WITH = WITHITEM = ASYNCWITH = \ EXPR = ASSIGN = handleChildren PASS = ignore # "expr" type nodes BOOLOP = UNARYOP = SET = ATTRIBUTE = STARRED = NAMECONSTANT = \ NAMEDEXPR = handleChildren def SUBSCRIPT(self, node): if _is_name_or_attr(node.value, 'Literal'): with self._enter_annotation(AnnotationState.NONE): self.handleChildren(node) elif _is_name_or_attr(node.value, 'Annotated'): self.handleNode(node.value, node) # py39+ if isinstance(node.slice, ast.Tuple): slice_tuple = node.slice # = 1 ): with self._enter_annotation(): self.handleNode(node.args[0], node) elif _is_typing(node.func, 'TypeVar', self.scopeStack): # TypeVar("T", "int", "str") omit += ["args"] annotated += [arg for arg in node.args[1:]] # TypeVar("T", bound="str") omit += ["keywords"] annotated += [k.value for k in node.keywords if k.arg == "bound"] not_annotated += [ (k, ["value"] if k.arg == "bound" else None) for k in node.keywords ] elif _is_typing(node.func, "TypedDict", self.scopeStack): # TypedDict("a", {"a": int}) if len(node.args) > 1 and isinstance(node.args[1], ast.Dict): omit += ["args"] annotated += node.args[1].values not_annotated += [ (arg, ["values"] if i == 1 else None) for i, arg in enumerate(node.args) ] # TypedDict("a", a=int) omit += ["keywords"] annotated += [k.value for k in node.keywords] not_annotated += [(k, ["value"]) for k in node.keywords] elif _is_typing(node.func, "NamedTuple", self.scopeStack): # NamedTuple("a", [("a", int)]) if ( len(node.args) > 1 and isinstance(node.args[1], (ast.Tuple, ast.List)) and all(isinstance(x, (ast.Tuple, ast.List)) and len(x.elts) == 2 for x in node.args[1].elts) ): omit += ["args"] annotated += [elt.elts[1] for elt in node.args[1].elts] not_annotated += [(elt.elts[0], None) for elt in node.args[1].elts] not_annotated += [ (arg, ["elts"] if i == 1 else None) for i, arg in enumerate(node.args) ] not_annotated += [(elt, "elts") for elt in node.args[1].elts] # NamedTuple("a", a=int) omit += ["keywords"] annotated += [k.value for k in node.keywords] not_annotated += [(k, ["value"]) for k in node.keywords] if omit: with self._enter_annotation(AnnotationState.NONE): for na_node, na_omit in not_annotated: self.handleChildren(na_node, omit=na_omit) self.handleChildren(node, omit=omit) with self._enter_annotation(): for annotated_node in annotated: self.handleNode(annotated_node, node) else: self.handleChildren(node) def _handle_percent_format(self, node): try: placeholders = parse_percent_format(node.left.s) except ValueError: self.report( messages.PercentFormatInvalidFormat, node, 'incomplete format', ) return named = set() positional_count = 0 positional = None for _, placeholder in placeholders: if placeholder is None: continue name, _, width, precision, conversion = placeholder if conversion == '%': continue if conversion not in VALID_CONVERSIONS: self.report( messages.PercentFormatUnsupportedFormatCharacter, node, conversion, ) if positional is None and conversion: positional = name is None for part in (width, precision): if part is not None and '*' in part: if not positional: self.report( messages.PercentFormatStarRequiresSequence, node, ) else: positional_count += 1 if positional and name is not None: self.report( messages.PercentFormatMixedPositionalAndNamed, node, ) return elif not positional and name is None: self.report( messages.PercentFormatMixedPositionalAndNamed, node, ) return if positional: positional_count += 1 else: named.add(name) if ( isinstance(node.right, (ast.List, ast.Tuple)) and # does not have any *splats (py35+ feature) not any( isinstance(elt, ast.Starred) for elt in node.right.elts ) ): substitution_count = len(node.right.elts) if positional and positional_count != substitution_count: self.report( messages.PercentFormatPositionalCountMismatch, node, positional_count, substitution_count, ) elif not positional: self.report(messages.PercentFormatExpectedMapping, node) if ( isinstance(node.right, ast.Dict) and all(isinstance(k, ast.Str) for k in node.right.keys) ): if positional and positional_count > 1: self.report(messages.PercentFormatExpectedSequence, node) return substitution_keys = {k.s for k in node.right.keys} extra_keys = substitution_keys - named missing_keys = named - substitution_keys if not positional and extra_keys: self.report( messages.PercentFormatExtraNamedArguments, node, ', '.join(sorted(extra_keys)), ) if not positional and missing_keys: self.report( messages.PercentFormatMissingArgument, node, ', '.join(sorted(missing_keys)), ) def BINOP(self, node): if ( isinstance(node.op, ast.Mod) and isinstance(node.left, ast.Str) ): self._handle_percent_format(node) self.handleChildren(node) def STR(self, node): if self._in_annotation: fn = functools.partial( self.handleStringAnnotation, node.s, node, node.lineno, node.col_offset, messages.ForwardAnnotationSyntaxError, ) if self._in_deferred: fn() else: self.deferFunction(fn) if PY38_PLUS: def CONSTANT(self, node): if isinstance(node.value, str): return self.STR(node) else: NUM = BYTES = ELLIPSIS = CONSTANT = ignore # "slice" type nodes SLICE = EXTSLICE = INDEX = handleChildren # expression contexts are node instances too, though being constants LOAD = STORE = DEL = AUGLOAD = AUGSTORE = PARAM = ignore # same for operators AND = OR = ADD = SUB = MULT = DIV = MOD = POW = LSHIFT = RSHIFT = \ BITOR = BITXOR = BITAND = FLOORDIV = INVERT = NOT = UADD = USUB = \ EQ = NOTEQ = LT = LTE = GT = GTE = IS = ISNOT = IN = NOTIN = \ MATMULT = ignore def RAISE(self, node): self.handleChildren(node) arg = node.exc if isinstance(arg, ast.Call): if is_notimplemented_name_node(arg.func): # Handle "raise NotImplemented(...)" self.report(messages.RaiseNotImplemented, node) elif is_notimplemented_name_node(arg): # Handle "raise NotImplemented" self.report(messages.RaiseNotImplemented, node) # additional node types COMPREHENSION = KEYWORD = FORMATTEDVALUE = handleChildren _in_fstring = False def JOINEDSTR(self, node): if ( # the conversion / etc. flags are parsed as f-strings without # placeholders not self._in_fstring and not any(isinstance(x, ast.FormattedValue) for x in node.values) ): self.report(messages.FStringMissingPlaceholders, node) self._in_fstring, orig = True, self._in_fstring try: self.handleChildren(node) finally: self._in_fstring = orig def DICT(self, node): # Complain if there are duplicate keys with different values # If they have the same value it's not going to cause potentially # unexpected behaviour so we'll not complain. keys = [ convert_to_value(key) for key in node.keys ] key_counts = counter(keys) duplicate_keys = [ key for key, count in key_counts.items() if count > 1 ] for key in duplicate_keys: key_indices = [i for i, i_key in enumerate(keys) if i_key == key] values = counter( convert_to_value(node.values[index]) for index in key_indices ) if any(count == 1 for value, count in values.items()): for key_index in key_indices: key_node = node.keys[key_index] if isinstance(key, VariableKey): self.report(messages.MultiValueRepeatedKeyVariable, key_node, key.name) else: self.report( messages.MultiValueRepeatedKeyLiteral, key_node, key, ) self.handleChildren(node) def IF(self, node): if isinstance(node.test, ast.Tuple) and node.test.elts != []: self.report(messages.IfTuple, node) self.handleChildren(node) IFEXP = IF def ASSERT(self, node): if isinstance(node.test, ast.Tuple) and node.test.elts != []: self.report(messages.AssertTuple, node) self.handleChildren(node) def GLOBAL(self, node): """ Keep track of globals declarations. """ global_scope_index = 1 if self._in_doctest() else 0 global_scope = self.scopeStack[global_scope_index] # Ignore 'global' statement in global scope. if self.scope is not global_scope: # One 'global' statement can bind multiple (comma-delimited) names. for node_name in node.names: node_value = Assignment(node_name, node) # Remove UndefinedName messages already reported for this name. # TODO: if the global is not used in this scope, it does not # become a globally defined name. See test_unused_global. self.messages = [ m for m in self.messages if not isinstance(m, messages.UndefinedName) or m.message_args[0] != node_name] # Bind name to global scope if it doesn't exist already. global_scope.setdefault(node_name, node_value) # Bind name to non-global scopes, but as already "used". node_value.used = (global_scope, node) for scope in self.scopeStack[global_scope_index + 1:]: scope[node_name] = node_value NONLOCAL = GLOBAL def GENERATOREXP(self, node): self.pushScope(GeneratorScope) self.handleChildren(node) self.popScope() LISTCOMP = DICTCOMP = SETCOMP = GENERATOREXP def NAME(self, node): """ Handle occurrence of Name (which can be a load/store/delete access.) """ # Locate the name in locals / function / globals scopes. if isinstance(node.ctx, ast.Load): self.handleNodeLoad(node) if (node.id == 'locals' and isinstance(self.scope, FunctionScope) and isinstance(node._pyflakes_parent, ast.Call)): # we are doing locals() call in current scope self.scope.usesLocals = True elif isinstance(node.ctx, ast.Store): self.handleNodeStore(node) elif isinstance(node.ctx, ast.Del): self.handleNodeDelete(node) else: # Unknown context raise RuntimeError(f"Got impossible expression context: {node.ctx!r}") def CONTINUE(self, node): # Walk the tree up until we see a loop (OK), a function or class # definition (not OK), for 'continue', a finally block (not OK), or # the top module scope (not OK) n = node while hasattr(n, '_pyflakes_parent'): n, n_child = n._pyflakes_parent, n if isinstance(n, (ast.While, ast.For, ast.AsyncFor)): # Doesn't apply unless it's in the loop itself if n_child not in n.orelse: return if isinstance(n, (ast.FunctionDef, ast.ClassDef)): break # Handle Try/TryFinally difference in Python < and >= 3.3 if hasattr(n, 'finalbody') and isinstance(node, ast.Continue): if n_child in n.finalbody and not PY38_PLUS: self.report(messages.ContinueInFinally, node) return if isinstance(node, ast.Continue): self.report(messages.ContinueOutsideLoop, node) else: # ast.Break self.report(messages.BreakOutsideLoop, node) BREAK = CONTINUE def RETURN(self, node): if isinstance(self.scope, (ClassScope, ModuleScope)): self.report(messages.ReturnOutsideFunction, node) return if ( node.value and hasattr(self.scope, 'returnValue') and not self.scope.returnValue ): self.scope.returnValue = node.value self.handleNode(node.value, node) def YIELD(self, node): if isinstance(self.scope, (ClassScope, ModuleScope)): self.report(messages.YieldOutsideFunction, node) return self.scope.isGenerator = True self.handleNode(node.value, node) AWAIT = YIELDFROM = YIELD def FUNCTIONDEF(self, node): for deco in node.decorator_list: self.handleNode(deco, node) self.LAMBDA(node) self.addBinding(node, FunctionDefinition(node.name, node)) # doctest does not process doctest within a doctest, # or in nested functions. if (self.withDoctest and not self._in_doctest() and not isinstance(self.scope, FunctionScope)): self.deferFunction(lambda: self.handleDoctests(node)) ASYNCFUNCTIONDEF = FUNCTIONDEF def LAMBDA(self, node): args = [] annotations = [] if PY38_PLUS: for arg in node.args.posonlyargs: args.append(arg.arg) annotations.append(arg.annotation) for arg in node.args.args + node.args.kwonlyargs: args.append(arg.arg) annotations.append(arg.annotation) defaults = node.args.defaults + node.args.kw_defaults has_annotations = not isinstance(node, ast.Lambda) for arg_name in ('vararg', 'kwarg'): wildcard = getattr(node.args, arg_name) if not wildcard: continue args.append(wildcard.arg) if has_annotations: annotations.append(wildcard.annotation) if has_annotations: annotations.append(node.returns) if len(set(args)) < len(args): for (idx, arg) in enumerate(args): if arg in args[:idx]: self.report(messages.DuplicateArgument, node, arg) for annotation in annotations: self.handleAnnotation(annotation, node) for default in defaults: self.handleNode(default, node) def runFunction(): self.pushScope() self.handleChildren(node, omit=['decorator_list', 'returns']) def checkUnusedAssignments(): """ Check to see if any assignments have not been used. """ for name, binding in self.scope.unusedAssignments(): self.report(messages.UnusedVariable, binding.source, name) self.deferAssignment(checkUnusedAssignments) self.popScope() self.deferFunction(runFunction) def ARGUMENTS(self, node): self.handleChildren(node, omit=('defaults', 'kw_defaults')) def ARG(self, node): self.addBinding(node, Argument(node.arg, self.getScopeNode(node))) def CLASSDEF(self, node): """ Check names used in a class definition, including its decorators, base classes, and the body of its definition. Additionally, add its name to the current scope. """ for deco in node.decorator_list: self.handleNode(deco, node) for baseNode in node.bases: self.handleNode(baseNode, node) for keywordNode in node.keywords: self.handleNode(keywordNode, node) self.pushScope(ClassScope) # doctest does not process doctest within a doctest # classes within classes are processed. if (self.withDoctest and not self._in_doctest() and not isinstance(self.scope, FunctionScope)): self.deferFunction(lambda: self.handleDoctests(node)) for stmt in node.body: self.handleNode(stmt, node) self.popScope() self.addBinding(node, ClassDefinition(node.name, node)) def AUGASSIGN(self, node): self.handleNodeLoad(node.target) self.handleNode(node.value, node) self.handleNode(node.target, node) def TUPLE(self, node): if isinstance(node.ctx, ast.Store): # Python 3 advanced tuple unpacking: a, *b, c = d. # Only one starred expression is allowed, and no more than 1<<8 # assignments are allowed before a stared expression. There is # also a limit of 1<<24 expressions after the starred expression, # which is impossible to test due to memory restrictions, but we # add it here anyway has_starred = False star_loc = -1 for i, n in enumerate(node.elts): if isinstance(n, ast.Starred): if has_starred: self.report(messages.TwoStarredExpressions, node) # The SyntaxError doesn't distinguish two from more # than two. break has_starred = True star_loc = i if star_loc >= 1 << 8 or len(node.elts) - star_loc - 1 >= 1 << 24: self.report(messages.TooManyExpressionsInStarredAssignment, node) self.handleChildren(node) LIST = TUPLE def IMPORT(self, node): for alias in node.names: if '.' in alias.name and not alias.asname: importation = SubmoduleImportation(alias.name, node) else: name = alias.asname or alias.name importation = Importation(name, node, alias.name) self.addBinding(node, importation) def IMPORTFROM(self, node): if node.module == '__future__': if not self.futuresAllowed: self.report(messages.LateFutureImport, node) else: self.futuresAllowed = False module = ('.' * node.level) + (node.module or '') for alias in node.names: name = alias.asname or alias.name if node.module == '__future__': importation = FutureImportation(name, node, self.scope) if alias.name not in __future__.all_feature_names: self.report(messages.FutureFeatureNotDefined, node, alias.name) if alias.name == 'annotations': self.annotationsFutureEnabled = True elif alias.name == '*': if not isinstance(self.scope, ModuleScope): self.report(messages.ImportStarNotPermitted, node, module) continue self.scope.importStarred = True self.report(messages.ImportStarUsed, node, module) importation = StarImportation(module, node) else: importation = ImportationFrom(name, node, module, alias.name) self.addBinding(node, importation) def TRY(self, node): handler_names = [] # List the exception handlers for i, handler in enumerate(node.handlers): if isinstance(handler.type, ast.Tuple): for exc_type in handler.type.elts: handler_names.append(getNodeName(exc_type)) elif handler.type: handler_names.append(getNodeName(handler.type)) if handler.type is None and i < len(node.handlers) - 1: self.report(messages.DefaultExceptNotLast, handler) # Memorize the except handlers and process the body self.exceptHandlers.append(handler_names) for child in node.body: self.handleNode(child, node) self.exceptHandlers.pop() # Process the other nodes: "except:", "else:", "finally:" self.handleChildren(node, omit='body') TRYSTAR = TRY def EXCEPTHANDLER(self, node): if node.name is None: self.handleChildren(node) return # If the name already exists in the scope, modify state of existing # binding. if node.name in self.scope: self.handleNodeStore(node) # 3.x: the name of the exception, which is not a Name node, but a # simple string, creates a local that is only bound within the scope of # the except: block. As such, temporarily remove the existing binding # to more accurately determine if the name is used in the except: # block. try: prev_definition = self.scope.pop(node.name) except KeyError: prev_definition = None self.handleNodeStore(node) self.handleChildren(node) # See discussion on https://github.com/PyCQA/pyflakes/pull/59 # We're removing the local name since it's being unbound after leaving # the except: block and it's always unbound if the except: block is # never entered. This will cause an "undefined name" error raised if # the checked code tries to use the name afterwards. # # Unless it's been removed already. Then do nothing. try: binding = self.scope.pop(node.name) except KeyError: pass else: if not binding.used: self.report(messages.UnusedVariable, node, node.name) # Restore. if prev_definition: self.scope[node.name] = prev_definition def ANNASSIGN(self, node): self.handleNode(node.target, node) self.handleAnnotation(node.annotation, node) # If the assignment has value, handle the *value* now. if node.value: # If the annotation is `TypeAlias`, handle the *value* as an annotation. if _is_typing(node.annotation, 'TypeAlias', self.scopeStack): self.handleAnnotation(node.value, node) else: self.handleNode(node.value, node) def COMPARE(self, node): left = node.left for op, right in zip(node.ops, node.comparators): if ( isinstance(op, (ast.Is, ast.IsNot)) and ( _is_const_non_singleton(left) or _is_const_non_singleton(right) ) ): self.report(messages.IsLiteral, node) left = right self.handleChildren(node) MATCH = MATCH_CASE = MATCHCLASS = MATCHOR = MATCHSEQUENCE = handleChildren MATCHSINGLETON = MATCHVALUE = handleChildren def _match_target(self, node): self.handleNodeStore(node) self.handleChildren(node) MATCHAS = MATCHMAPPING = MATCHSTAR = _match_target