# Copyright (c) 2006-2015 LOGILAB S.A. (Paris, FRANCE) # Copyright (c) 2012-2014 Google, Inc. # Copyright (c) 2013 buck@yelp.com # Copyright (c) 2014-2020 Claudiu Popa # Copyright (c) 2014 Brett Cannon # Copyright (c) 2014 Arun Persaud # Copyright (c) 2015-2016 Moises Lopez # Copyright (c) 2015 Dmitry Pribysh # Copyright (c) 2015 Cezar # Copyright (c) 2015 Florian Bruhin # Copyright (c) 2015 Noam Yorav-Raphael # Copyright (c) 2015 James Morgensen # Copyright (c) 2015 Ionel Cristian Maries # Copyright (c) 2016, 2021 Ashley Whetter # Copyright (c) 2016 Jared Garst # Copyright (c) 2016 Maik Röder # Copyright (c) 2016 Glenn Matthews # Copyright (c) 2017, 2020 hippo91 # Copyright (c) 2017 Michka Popoff # Copyright (c) 2017 Łukasz Rogalski # Copyright (c) 2017 Erik Wright # Copyright (c) 2018 Lucas Cimon # Copyright (c) 2018 Hornwitser # Copyright (c) 2018 ssolanki # Copyright (c) 2018 Natalie Serebryakova # Copyright (c) 2018 Mike Frysinger # Copyright (c) 2018 Sushobhit <31987769+sushobhit27@users.noreply.github.com> # Copyright (c) 2018 Marianna Polatoglou # Copyright (c) 2019-2021 Pierre Sassoulas # Copyright (c) 2019, 2021 Nick Drozd # Copyright (c) 2019 Hugo van Kemenade # Copyright (c) 2019 Nick Smith # Copyright (c) 2019 Paul Renvoisé # Copyright (c) 2020 Peter Kolbus # Copyright (c) 2020 Damien Baty # Copyright (c) 2020 Anthony Sottile # Copyright (c) 2021 Tushar Sadhwani # Copyright (c) 2021 Daniël van Noord <13665637+DanielNoord@users.noreply.github.com> # Copyright (c) 2021 Marc Mueller <30130371+cdce8p@users.noreply.github.com> # Copyright (c) 2021 Will Shanks # Copyright (c) 2021 Matus Valo # Copyright (c) 2021 Yu Shao, Pang <36848472+yushao2@users.noreply.github.com> # Copyright (c) 2021 Andrew Howe # Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html # For details: https://github.com/PyCQA/pylint/blob/main/LICENSE """imports checkers for Python code""" import collections import copy import os import sys from distutils import sysconfig from typing import Any, Dict, List, Optional, Set, Tuple, Union import astroid from astroid import nodes from pylint.checkers import BaseChecker, DeprecatedMixin from pylint.checkers.utils import ( check_messages, get_import_name, is_from_fallback_block, is_node_in_guarded_import_block, is_typing_guard, node_ignores_exception, ) from pylint.exceptions import EmptyReportError from pylint.graph import DotBackend, get_cycles from pylint.interfaces import IAstroidChecker from pylint.lint import PyLinter from pylint.reporters.ureports.nodes import Paragraph, Section, VerbatimText from pylint.utils import IsortDriver, get_global_option def _qualified_names(modname): """Split the names of the given module into subparts For example, _qualified_names('pylint.checkers.ImportsChecker') returns ['pylint', 'pylint.checkers', 'pylint.checkers.ImportsChecker'] """ names = modname.split(".") return [".".join(names[0 : i + 1]) for i in range(len(names))] def _get_first_import(node, context, name, base, level, alias): """return the node where [base.] is imported or None if not found""" fullname = f"{base}.{name}" if base else name first = None found = False for first in context.body: if first is node: continue if first.scope() is node.scope() and first.fromlineno > node.fromlineno: continue if isinstance(first, nodes.Import): if any(fullname == iname[0] for iname in first.names): found = True break elif isinstance(first, nodes.ImportFrom): if level == first.level: for imported_name, imported_alias in first.names: if fullname == f"{first.modname}.{imported_name}": found = True break if ( name != "*" and name == imported_name and not (alias or imported_alias) ): found = True break if found: break if found and not astroid.are_exclusive(first, node): return first return None def _ignore_import_failure(node, modname, ignored_modules): for submodule in _qualified_names(modname): if submodule in ignored_modules: return True if is_node_in_guarded_import_block(node): # Ignore import failure if part of guarded import block # I.e. `sys.version_info` or `typing.TYPE_CHECKING` return True return node_ignores_exception(node, ImportError) # utilities to represents import dependencies as tree and dot graph ########### def _make_tree_defs(mod_files_list): """get a list of 2-uple (module, list_of_files_which_import_this_module), it will return a dictionary to represent this as a tree """ tree_defs = {} for mod, files in mod_files_list: node = (tree_defs, ()) for prefix in mod.split("."): node = node[0].setdefault(prefix, [{}, []]) node[1] += files return tree_defs def _repr_tree_defs(data, indent_str=None): """return a string which represents imports as a tree""" lines = [] nodes_items = data.items() for i, (mod, (sub, files)) in enumerate(sorted(nodes_items, key=lambda x: x[0])): files = "" if not files else f"({','.join(sorted(files))})" if indent_str is None: lines.append(f"{mod} {files}") sub_indent_str = " " else: lines.append(fr"{indent_str}\-{mod} {files}") if i == len(nodes_items) - 1: sub_indent_str = f"{indent_str} " else: sub_indent_str = f"{indent_str}| " if sub: lines.append(_repr_tree_defs(sub, sub_indent_str)) return "\n".join(lines) def _dependencies_graph(filename: str, dep_info: Dict[str, Set[str]]) -> str: """write dependencies as a dot (graphviz) file""" done = {} printer = DotBackend(os.path.splitext(os.path.basename(filename))[0], rankdir="LR") printer.emit('URL="." node[shape="box"]') for modname, dependencies in sorted(dep_info.items()): sorted_dependencies = sorted(dependencies) done[modname] = 1 printer.emit_node(modname) for depmodname in sorted_dependencies: if depmodname not in done: done[depmodname] = 1 printer.emit_node(depmodname) for depmodname, dependencies in sorted(dep_info.items()): for modname in sorted(dependencies): printer.emit_edge(modname, depmodname) return printer.generate(filename) def _make_graph( filename: str, dep_info: Dict[str, Set[str]], sect: Section, gtype: str ): """generate a dependencies graph and add some information about it in the report's section """ outputfile = _dependencies_graph(filename, dep_info) sect.append(Paragraph((f"{gtype}imports graph has been written to {outputfile}",))) # the import checker itself ################################################### MSGS = { "E0401": ( "Unable to import %s", "import-error", "Used when pylint has been unable to import a module.", {"old_names": [("F0401", "old-import-error")]}, ), "E0402": ( "Attempted relative import beyond top-level package", "relative-beyond-top-level", "Used when a relative import tries to access too many levels " "in the current package.", ), "R0401": ( "Cyclic import (%s)", "cyclic-import", "Used when a cyclic import between two or more modules is detected.", ), "R0402": ( "Use 'from %s import %s' instead", "consider-using-from-import", "Emitted when a submodule of a package is imported and " "aliased with the same name. " "E.g., instead of ``import concurrent.futures as futures`` use " "``from concurrent import futures``", ), "W0401": ( "Wildcard import %s", "wildcard-import", "Used when `from module import *` is detected.", ), "W0402": ( "Uses of a deprecated module %r", "deprecated-module", "Used a module marked as deprecated is imported.", ), "W0404": ( "Reimport %r (imported line %s)", "reimported", "Used when a module is reimported multiple times.", ), "W0406": ( "Module import itself", "import-self", "Used when a module is importing itself.", ), "W0407": ( "Prefer importing %r instead of %r", "preferred-module", "Used when a module imported has a preferred replacement module.", ), "W0410": ( "__future__ import is not the first non docstring statement", "misplaced-future", "Python 2.5 and greater require __future__ import to be the " "first non docstring statement in the module.", ), "C0410": ( "Multiple imports on one line (%s)", "multiple-imports", "Used when import statement importing multiple modules is detected.", ), "C0411": ( "%s should be placed before %s", "wrong-import-order", "Used when PEP8 import order is not respected (standard imports " "first, then third-party libraries, then local imports)", ), "C0412": ( "Imports from package %s are not grouped", "ungrouped-imports", "Used when imports are not grouped by packages", ), "C0413": ( 'Import "%s" should be placed at the top of the module', "wrong-import-position", "Used when code and imports are mixed", ), "C0414": ( "Import alias does not rename original package", "useless-import-alias", "Used when an import alias is same as original package." "e.g using import numpy as numpy instead of import numpy as np", ), "C0415": ( "Import outside toplevel (%s)", "import-outside-toplevel", "Used when an import statement is used anywhere other than the module " "toplevel. Move this import to the top of the file.", ), } DEFAULT_STANDARD_LIBRARY = () DEFAULT_KNOWN_THIRD_PARTY = ("enchant",) DEFAULT_PREFERRED_MODULES = () class ImportsChecker(DeprecatedMixin, BaseChecker): """checks for * external modules dependencies * relative / wildcard imports * cyclic imports * uses of deprecated modules * uses of modules instead of preferred modules """ __implements__ = IAstroidChecker name = "imports" msgs = MSGS priority = -2 default_deprecated_modules = () options = ( ( "deprecated-modules", { "default": default_deprecated_modules, "type": "csv", "metavar": "", "help": "Deprecated modules which should not be used," " separated by a comma.", }, ), ( "preferred-modules", { "default": DEFAULT_PREFERRED_MODULES, "type": "csv", "metavar": "", "help": "Couples of modules and preferred modules," " separated by a comma.", }, ), ( "import-graph", { "default": "", "type": "string", "metavar": "", "help": "Output a graph (.gv or any supported image format) of" " all (i.e. internal and external) dependencies to the given file" " (report RP0402 must not be disabled).", }, ), ( "ext-import-graph", { "default": "", "type": "string", "metavar": "", "help": "Output a graph (.gv or any supported image format)" " of external dependencies to the given file" " (report RP0402 must not be disabled).", }, ), ( "int-import-graph", { "default": "", "type": "string", "metavar": "", "help": "Output a graph (.gv or any supported image format)" " of internal dependencies to the given file" " (report RP0402 must not be disabled).", }, ), ( "known-standard-library", { "default": DEFAULT_STANDARD_LIBRARY, "type": "csv", "metavar": "", "help": "Force import order to recognize a module as part of " "the standard compatibility libraries.", }, ), ( "known-third-party", { "default": DEFAULT_KNOWN_THIRD_PARTY, "type": "csv", "metavar": "", "help": "Force import order to recognize a module as part of " "a third party library.", }, ), ( "allow-any-import-level", { "default": (), "type": "csv", "metavar": "", "help": ( "List of modules that can be imported at any level, not just " "the top level one." ), }, ), ( "analyse-fallback-blocks", { "default": False, "type": "yn", "metavar": "", "help": "Analyse import fallback blocks. This can be used to " "support both Python 2 and 3 compatible code, which " "means that the block might have code that exists " "only in one or another interpreter, leading to false " "positives when analysed.", }, ), ( "allow-wildcard-with-all", { "default": False, "type": "yn", "metavar": "", "help": "Allow wildcard imports from modules that define __all__.", }, ), ) def __init__( self, linter: Optional[PyLinter] = None ): # pylint: disable=super-init-not-called # See https://github.com/PyCQA/pylint/issues/4941 BaseChecker.__init__(self, linter) self.import_graph: collections.defaultdict = collections.defaultdict(set) self._imports_stack: List[Tuple[Any, Any]] = [] self._first_non_import_node = None self._module_pkg: Dict[ Any, Any ] = {} # mapping of modules to the pkg they belong in self._allow_any_import_level: Set[Any] = set() self.reports = ( ("RP0401", "External dependencies", self._report_external_dependencies), ("RP0402", "Modules dependencies graph", self._report_dependencies_graph), ) self._site_packages = self._compute_site_packages() @staticmethod def _compute_site_packages(): def _normalized_path(path): return os.path.normcase(os.path.abspath(path)) paths = set() real_prefix = getattr(sys, "real_prefix", None) for prefix in filter(None, (real_prefix, sys.prefix)): path = sysconfig.get_python_lib(prefix=prefix) path = _normalized_path(path) paths.add(path) # Handle Debian's derivatives /usr/local. if os.path.isfile("/etc/debian_version"): for prefix in filter(None, (real_prefix, sys.prefix)): libpython = os.path.join( prefix, "local", "lib", "python" + sysconfig.get_python_version(), "dist-packages", ) paths.add(libpython) return paths def open(self): """called before visiting project (i.e set of modules)""" self.linter.stats.dependencies = {} self.linter.stats = self.linter.stats self.import_graph = collections.defaultdict(set) self._module_pkg = {} # mapping of modules to the pkg they belong in self._excluded_edges = collections.defaultdict(set) self._ignored_modules = get_global_option(self, "ignored-modules", default=[]) # Build a mapping {'module': 'preferred-module'} self.preferred_modules = dict( module.split(":") for module in self.config.preferred_modules if ":" in module ) self._allow_any_import_level = set(self.config.allow_any_import_level) def _import_graph_without_ignored_edges(self): filtered_graph = copy.deepcopy(self.import_graph) for node in filtered_graph: filtered_graph[node].difference_update(self._excluded_edges[node]) return filtered_graph def close(self): """called before visiting project (i.e set of modules)""" if self.linter.is_message_enabled("cyclic-import"): graph = self._import_graph_without_ignored_edges() vertices = list(graph) for cycle in get_cycles(graph, vertices=vertices): self.add_message("cyclic-import", args=" -> ".join(cycle)) def deprecated_modules(self): """Callback returning the deprecated modules.""" return self.config.deprecated_modules @check_messages(*MSGS) def visit_import(self, node: nodes.Import) -> None: """triggered when an import statement is seen""" self._check_reimport(node) self._check_import_as_rename(node) self._check_toplevel(node) names = [name for name, _ in node.names] if len(names) >= 2: self.add_message("multiple-imports", args=", ".join(names), node=node) for name in names: self.check_deprecated_module(node, name) self._check_preferred_module(node, name) imported_module = self._get_imported_module(node, name) if isinstance(node.parent, nodes.Module): # Allow imports nested self._check_position(node) if isinstance(node.scope(), nodes.Module): self._record_import(node, imported_module) if imported_module is None: continue self._add_imported_module(node, imported_module.name) @check_messages(*MSGS) def visit_importfrom(self, node: nodes.ImportFrom) -> None: """triggered when a from statement is seen""" basename = node.modname imported_module = self._get_imported_module(node, basename) self._check_import_as_rename(node) self._check_misplaced_future(node) self.check_deprecated_module(node, basename) self._check_preferred_module(node, basename) self._check_wildcard_imports(node, imported_module) self._check_same_line_imports(node) self._check_reimport(node, basename=basename, level=node.level) self._check_toplevel(node) if isinstance(node.parent, nodes.Module): # Allow imports nested self._check_position(node) if isinstance(node.scope(), nodes.Module): self._record_import(node, imported_module) if imported_module is None: return for name, _ in node.names: if name != "*": self._add_imported_module(node, f"{imported_module.name}.{name}") else: self._add_imported_module(node, imported_module.name) @check_messages(*MSGS) def leave_module(self, node: nodes.Module) -> None: # Check imports are grouped by category (standard, 3rd party, local) std_imports, ext_imports, loc_imports = self._check_imports_order(node) # Check that imports are grouped by package within a given category met_import: Set[str] = set() # set for 'import x' style met_from: Set[str] = set() # set for 'from x import y' style current_package = None for import_node, import_name in std_imports + ext_imports + loc_imports: if not self.linter.is_message_enabled( "ungrouped-imports", import_node.fromlineno ): continue met = met_from if isinstance(import_node, nodes.ImportFrom) else met_import package, _, _ = import_name.partition(".") if ( current_package and current_package != package and package in met and is_node_in_guarded_import_block(import_node) is False ): self.add_message("ungrouped-imports", node=import_node, args=package) current_package = package met.add(package) self._imports_stack = [] self._first_non_import_node = None def compute_first_non_import_node(self, node): if not self.linter.is_message_enabled("wrong-import-position", node.fromlineno): return # if the node does not contain an import instruction, and if it is the # first node of the module, keep a track of it (all the import positions # of the module will be compared to the position of this first # instruction) if self._first_non_import_node: return if not isinstance(node.parent, nodes.Module): return nested_allowed = [nodes.TryExcept, nodes.TryFinally] is_nested_allowed = [ allowed for allowed in nested_allowed if isinstance(node, allowed) ] if is_nested_allowed and any( node.nodes_of_class((nodes.Import, nodes.ImportFrom)) ): return if isinstance(node, nodes.Assign): # Add compatibility for module level dunder names # https://www.python.org/dev/peps/pep-0008/#module-level-dunder-names valid_targets = [ isinstance(target, nodes.AssignName) and target.name.startswith("__") and target.name.endswith("__") for target in node.targets ] if all(valid_targets): return self._first_non_import_node = node visit_tryfinally = ( visit_tryexcept ) = ( visit_assignattr ) = ( visit_assign ) = ( visit_ifexp ) = visit_comprehension = visit_expr = visit_if = compute_first_non_import_node def visit_functiondef(self, node: nodes.FunctionDef) -> None: if not self.linter.is_message_enabled("wrong-import-position", node.fromlineno): return # If it is the first non import instruction of the module, record it. if self._first_non_import_node: return # Check if the node belongs to an `If` or a `Try` block. If they # contain imports, skip recording this node. if not isinstance(node.parent.scope(), nodes.Module): return root = node while not isinstance(root.parent, nodes.Module): root = root.parent if isinstance(root, (nodes.If, nodes.TryFinally, nodes.TryExcept)): if any(root.nodes_of_class((nodes.Import, nodes.ImportFrom))): return self._first_non_import_node = node visit_classdef = visit_for = visit_while = visit_functiondef def _check_misplaced_future(self, node): basename = node.modname if basename == "__future__": # check if this is the first non-docstring statement in the module prev = node.previous_sibling() if prev: # consecutive future statements are possible if not ( isinstance(prev, nodes.ImportFrom) and prev.modname == "__future__" ): self.add_message("misplaced-future", node=node) return def _check_same_line_imports(self, node): # Detect duplicate imports on the same line. names = (name for name, _ in node.names) counter = collections.Counter(names) for name, count in counter.items(): if count > 1: self.add_message("reimported", node=node, args=(name, node.fromlineno)) def _check_position(self, node): """Check `node` import or importfrom node position is correct Send a message if `node` comes before another instruction """ # if a first non-import instruction has already been encountered, # it means the import comes after it and therefore is not well placed if self._first_non_import_node: self.add_message("wrong-import-position", node=node, args=node.as_string()) def _record_import(self, node, importedmodnode): """Record the package `node` imports from""" if isinstance(node, nodes.ImportFrom): importedname = node.modname else: importedname = importedmodnode.name if importedmodnode else None if not importedname: importedname = node.names[0][0].split(".")[0] if isinstance(node, nodes.ImportFrom) and (node.level or 0) >= 1: # We need the importedname with first point to detect local package # Example of node: # 'from .my_package1 import MyClass1' # the output should be '.my_package1' instead of 'my_package1' # Example of node: # 'from . import my_package2' # the output should be '.my_package2' instead of '{pyfile}' importedname = "." + importedname self._imports_stack.append((node, importedname)) @staticmethod def _is_fallback_import(node, imports): imports = [import_node for (import_node, _) in imports] return any(astroid.are_exclusive(import_node, node) for import_node in imports) def _check_imports_order(self, _module_node): """Checks imports of module `node` are grouped by category Imports must follow this order: standard, 3rd party, local """ std_imports = [] third_party_imports = [] first_party_imports = [] # need of a list that holds third or first party ordered import external_imports = [] local_imports = [] third_party_not_ignored = [] first_party_not_ignored = [] local_not_ignored = [] isort_driver = IsortDriver(self.config) for node, modname in self._imports_stack: if modname.startswith("."): package = "." + modname.split(".")[1] else: package = modname.split(".")[0] nested = not isinstance(node.parent, nodes.Module) ignore_for_import_order = not self.linter.is_message_enabled( "wrong-import-order", node.fromlineno ) import_category = isort_driver.place_module(package) node_and_package_import = (node, package) if import_category in {"FUTURE", "STDLIB"}: std_imports.append(node_and_package_import) wrong_import = ( third_party_not_ignored or first_party_not_ignored or local_not_ignored ) if self._is_fallback_import(node, wrong_import): continue if wrong_import and not nested: self.add_message( "wrong-import-order", node=node, args=( f'standard import "{node.as_string()}"', f'"{wrong_import[0][0].as_string()}"', ), ) elif import_category == "THIRDPARTY": third_party_imports.append(node_and_package_import) external_imports.append(node_and_package_import) if not nested: if not ignore_for_import_order: third_party_not_ignored.append(node_and_package_import) else: self.linter.add_ignored_message( "wrong-import-order", node.fromlineno, node ) wrong_import = first_party_not_ignored or local_not_ignored if wrong_import and not nested: self.add_message( "wrong-import-order", node=node, args=( f'third party import "{node.as_string()}"', f'"{wrong_import[0][0].as_string()}"', ), ) elif import_category == "FIRSTPARTY": first_party_imports.append(node_and_package_import) external_imports.append(node_and_package_import) if not nested: if not ignore_for_import_order: first_party_not_ignored.append(node_and_package_import) else: self.linter.add_ignored_message( "wrong-import-order", node.fromlineno, node ) wrong_import = local_not_ignored if wrong_import and not nested: self.add_message( "wrong-import-order", node=node, args=( f'first party import "{node.as_string()}"', f'"{wrong_import[0][0].as_string()}"', ), ) elif import_category == "LOCALFOLDER": local_imports.append((node, package)) if not nested: if not ignore_for_import_order: local_not_ignored.append((node, package)) else: self.linter.add_ignored_message( "wrong-import-order", node.fromlineno, node ) return std_imports, external_imports, local_imports def _get_imported_module(self, importnode, modname): try: return importnode.do_import_module(modname) except astroid.TooManyLevelsError: if _ignore_import_failure(importnode, modname, self._ignored_modules): return None self.add_message("relative-beyond-top-level", node=importnode) except astroid.AstroidSyntaxError as exc: message = f"Cannot import {modname!r} due to syntax error {str(exc.error)!r}" # pylint: disable=no-member; false positive self.add_message("syntax-error", line=importnode.lineno, args=message) except astroid.AstroidBuildingException: if not self.linter.is_message_enabled("import-error"): return None if _ignore_import_failure(importnode, modname, self._ignored_modules): return None if not self.config.analyse_fallback_blocks and is_from_fallback_block( importnode ): return None dotted_modname = get_import_name(importnode, modname) self.add_message("import-error", args=repr(dotted_modname), node=importnode) return None def _add_imported_module( self, node: Union[nodes.Import, nodes.ImportFrom], importedmodname: str ) -> None: """notify an imported module, used to analyze dependencies""" module_file = node.root().file context_name = node.root().name base = os.path.splitext(os.path.basename(module_file))[0] try: importedmodname = astroid.modutils.get_module_part( importedmodname, module_file ) except ImportError: pass in_type_checking_block = isinstance(node.parent, nodes.If) and is_typing_guard( node.parent ) if context_name == importedmodname: self.add_message("import-self", node=node) elif not astroid.modutils.is_standard_module(importedmodname): # if this is not a package __init__ module if base != "__init__" and context_name not in self._module_pkg: # record the module's parent, or the module itself if this is # a top level module, as the package it belongs to self._module_pkg[context_name] = context_name.rsplit(".", 1)[0] # handle dependencies dependencies_stat: Dict[str, Union[Set]] = self.linter.stats.dependencies importedmodnames = dependencies_stat.setdefault(importedmodname, set()) if context_name not in importedmodnames: importedmodnames.add(context_name) # update import graph self.import_graph[context_name].add(importedmodname) if ( not self.linter.is_message_enabled("cyclic-import", line=node.lineno) or in_type_checking_block ): self._excluded_edges[context_name].add(importedmodname) def _check_preferred_module(self, node, mod_path): """check if the module has a preferred replacement""" if mod_path in self.preferred_modules: self.add_message( "preferred-module", node=node, args=(self.preferred_modules[mod_path], mod_path), ) def _check_import_as_rename( self, node: Union[nodes.Import, nodes.ImportFrom] ) -> None: names = node.names for name in names: if not all(name): return splitted_packages = name[0].rsplit(".", maxsplit=1) import_name = splitted_packages[-1] aliased_name = name[1] if import_name != aliased_name: continue if len(splitted_packages) == 1: self.add_message("useless-import-alias", node=node) elif len(splitted_packages) == 2: self.add_message( "consider-using-from-import", node=node, args=(splitted_packages[0], import_name), ) def _check_reimport(self, node, basename=None, level=None): """check if the import is necessary (i.e. not already done)""" if not self.linter.is_message_enabled("reimported"): return frame = node.frame() root = node.root() contexts = [(frame, level)] if root is not frame: contexts.append((root, None)) for known_context, known_level in contexts: for name, alias in node.names: first = _get_first_import( node, known_context, name, basename, known_level, alias ) if first is not None: self.add_message( "reimported", node=node, args=(name, first.fromlineno) ) def _report_external_dependencies(self, sect, _, _dummy): """return a verbatim layout for displaying dependencies""" dep_info = _make_tree_defs(self._external_dependencies_info().items()) if not dep_info: raise EmptyReportError() tree_str = _repr_tree_defs(dep_info) sect.append(VerbatimText(tree_str)) def _report_dependencies_graph(self, sect, _, _dummy): """write dependencies as a dot (graphviz) file""" dep_info = self.linter.stats.dependencies if not dep_info or not ( self.config.import_graph or self.config.ext_import_graph or self.config.int_import_graph ): raise EmptyReportError() filename = self.config.import_graph if filename: _make_graph(filename, dep_info, sect, "") filename = self.config.ext_import_graph if filename: _make_graph(filename, self._external_dependencies_info(), sect, "external ") filename = self.config.int_import_graph if filename: _make_graph(filename, self._internal_dependencies_info(), sect, "internal ") def _filter_dependencies_graph(self, internal): """build the internal or the external dependency graph""" graph = collections.defaultdict(set) for importee, importers in self.linter.stats.dependencies.items(): for importer in importers: package = self._module_pkg.get(importer, importer) is_inside = importee.startswith(package) if is_inside and internal or not is_inside and not internal: graph[importee].add(importer) return graph @astroid.decorators.cached def _external_dependencies_info(self): """return cached external dependencies information or build and cache them """ return self._filter_dependencies_graph(internal=False) @astroid.decorators.cached def _internal_dependencies_info(self): """return cached internal dependencies information or build and cache them """ return self._filter_dependencies_graph(internal=True) def _check_wildcard_imports(self, node, imported_module): if node.root().package: # Skip the check if in __init__.py issue #2026 return wildcard_import_is_allowed = self._wildcard_import_is_allowed(imported_module) for name, _ in node.names: if name == "*" and not wildcard_import_is_allowed: self.add_message("wildcard-import", args=node.modname, node=node) def _wildcard_import_is_allowed(self, imported_module): return ( self.config.allow_wildcard_with_all and imported_module is not None and "__all__" in imported_module.locals ) def _check_toplevel(self, node): """Check whether the import is made outside the module toplevel.""" # If the scope of the import is a module, then obviously it is # not outside the module toplevel. if isinstance(node.scope(), nodes.Module): return module_names = [ f"{node.modname}.{name[0]}" if isinstance(node, nodes.ImportFrom) else name[0] for name in node.names ] # Get the full names of all the imports that are only allowed at the module level scoped_imports = [ name for name in module_names if name not in self._allow_any_import_level ] if scoped_imports: self.add_message( "import-outside-toplevel", args=", ".join(scoped_imports), node=node ) def register(linter): """required method to auto register this checker""" linter.register_checker(ImportsChecker(linter))