from __future__ import annotations import ast import re from importlib.metadata import version from typing import Any from typing import Generator from typing import Literal from typing import Pattern from flake8.options.manager import OptionManager class ImportChecker: """ Flake8 plugin to make your import statements tidier. """ name = "flake8-tidy-imports" version = version("flake8-tidy-imports") # The naming follows the approach described by mypy: # https://mypy.readthedocs.io/en/stable/config_file.html#config-file-format banned_modules: dict[str, str] banned_structured_patterns: list[tuple[str, str]] banned_unstructured_patterns: list[tuple[Pattern[str], str]] ban_relative_imports: Literal["", "parents", "true"] def __init__(self, tree: ast.AST) -> None: self.tree = tree @classmethod def add_options(cls, parser: OptionManager) -> None: parser.add_option( "--banned-modules", action="store", parse_from_config=True, default="", help=( "A map of modules to ban to the error messages to " + "display in the error." ), ) parser.add_option( "--ban-relative-imports", action="store", nargs="?", const="true", parse_from_config=True, choices=["", "parents", "true"], default="", help="Ban relative imports, from parental modules or in all cases.", ) @classmethod def parse_options(cls, options: Any) -> None: lines = [ line.strip() for line in options.banned_modules.split("\n") if line.strip() ] cls.banned_modules = {} cls.banned_structured_patterns = [] cls.banned_unstructured_patterns = [] for line in lines: if line == "{python2to3}": cls.banned_modules.update(cls.python2to3_banned_modules) continue if "=" not in line: raise ValueError("'=' not found") module, message = line.split("=", 1) module = module.strip() message = message.strip() if "*" in module[:-1] or module == "*": # unstructured cls.banned_unstructured_patterns.append( (cls.compile_unstructured_glob(module), message) ) elif module.endswith(".*"): # structured cls.banned_structured_patterns.append((module, message)) # Also check for exact matches without the wilcard # e.g. "foo.*" matches "foo" prefix = module[:-2] if prefix not in cls.banned_modules: cls.banned_modules[prefix] = message else: cls.banned_modules[module] = message # Sort the structured patterns so we match the specifc ones first. cls.banned_structured_patterns.sort(key=lambda x: len(x[0]), reverse=True) cls.ban_relative_imports = options.ban_relative_imports message_I250 = "I250 Unnecessary import alias - rewrite as '{}'." message_I251 = "I251 Banned import '{name}' used - {msg}." def run(self) -> Generator[tuple[int, int, str, type[Any]], None, None]: rule_funcs = (self.rule_I250, self.rule_I251, self.rule_I252) for node in ast.walk(self.tree): for rule_func in rule_funcs: yield from rule_func(node) def rule_I250( self, node: ast.AST ) -> Generator[tuple[int, int, str, type[Any]], None, None]: if isinstance(node, ast.Import): for alias in node.names: if "." not in alias.name: from_name = None imported_name = alias.name else: from_name, imported_name = alias.name.rsplit(".", 1) if imported_name == alias.asname: if from_name: rewritten = f"from {from_name} import {imported_name}" else: rewritten = f"import {imported_name}" yield ( node.lineno, node.col_offset, self.message_I250.format(rewritten), type(self), ) elif isinstance(node, ast.ImportFrom): for alias in node.names: if alias.name == alias.asname: rewritten = f"from {node.module} import {alias.name}" yield ( node.lineno, node.col_offset, self.message_I250.format(rewritten), type(self), ) @staticmethod def compile_unstructured_glob(s: str) -> Pattern[str]: # Convert the patter to a regex such that ".*" # matches zero or more moduels. parts = s.split(".") transformed_parts = [ "(\\..*)?" if p == "*" else "\\." + re.escape(p) for p in parts ] if parts[0] == "*": transformed_parts[0] = ".*" else: transformed_parts[0] = re.escape(parts[0]) return re.compile("".join(transformed_parts) + "\\Z") def _is_module_banned(self, module_name: str) -> tuple[bool, str]: if module_name in self.banned_modules: return True, self.banned_modules[module_name] # Check unustructed wildcards for banned_pattern, msg in self.banned_unstructured_patterns: if banned_pattern.match(module_name): return True, msg # Check structured wildcards for banned_prefix, msg in self.banned_structured_patterns: if module_name.startswith(banned_prefix[:-1]): return True, msg return False, "" def rule_I251( self, node: ast.AST ) -> Generator[tuple[int, int, str, type[Any]], None, None]: if isinstance(node, ast.Import): module_names = [alias.name for alias in node.names] elif isinstance(node, ast.ImportFrom): node_module = node.module or "" module_names = [node_module] for alias in node.names: module_names.append(f"{node_module}.{alias.name}") else: return # Sort from most to least specific paths. module_names.sort(key=len, reverse=True) warned: set[str] = set() for module_name in module_names: is_banned, msg = self._is_module_banned(module_name) if is_banned: message = self.message_I251.format(name=module_name, msg=msg) if any(mod.startswith(module_name) for mod in warned): # Do not show an error for this line if we already showed # a more specific error. continue else: warned.add(module_name) yield (node.lineno, node.col_offset, message, type(self)) def rule_I252( self, node: ast.AST ) -> Generator[tuple[int, int, str, type[Any]], None, None]: if self.ban_relative_imports == "": return elif self.ban_relative_imports == "parents": min_node_level = 1 message = "I252 Relative imports from parent modules are banned." else: min_node_level = 0 message = "I252 Relative imports are banned." if ( self.ban_relative_imports and isinstance(node, ast.ImportFrom) and node.level > min_node_level ): yield (node.lineno, node.col_offset, message, type(self)) python2to3_banned_modules = { "__builtin__": "use six.moves.builtins as a drop-in replacement", "_winreg": "use six.moves.winreg as a drop-in replacement", "anydbm": "use dbm as a drop-in replacement", "asynchat.fifo": "removed in Python 3", "audiodev": "removed in Python 3", "BaseHTTPServer": "use six.moves.BaseHTTPServer as a drop-in replacement", "Bastion": "removed in Python 3", "bsddb185": "use bsddb3 instead", "Canvas": "removed in Python 3", "cfmfile": "removed in Python 3", "CGIHTTPServer": "use six.moves.CGIHTTPServer as a drop-in replacement", "cl": "removed in Python 3", "commands": "removed in Python 3, use subprocess instead", "compiler": "removed in Python 3, use ast instead", "ConfigParser": "use six.moves.configparser as a drop-in replacement", "contextlib.nested": ( "use contextlib2.ExitStack or the shim in " + "http://stackoverflow.com/a/39158985/303931" ), "Cookie": "use six.moves.http_cookies as a drop-in replacement", "cookielib": "use six.moves.http_cookiejar as a drop-in replacement", "copy_reg": "use six.moves.copyreg as a drop-in replacement", "cPickle": "use six.moves.cPickle as a drop-in replacement", "cStringIO": "moved in Python 3, use io.StringIO or io.BytesIO instead", "Dialog": "use six.moves.tkinter_dialog as a drop-in replacement", "dircache": "removed in Python 3", "dl": "removed in Python 3, use ctypes instead", "DocXMLRPCServer": "use six.moves.xmlrpc_server instead", "dummy_thread": "use six.moves._dummy_thread as a drop-in replacement", "email.MIMEBase": "use six.moves.email_mime_base as a drop-in replacement", "email.MIMEMultipart": ( "use six.moves.email_mime_multipart as a" + " drop-in replacement" ), "email.MIMENonMultipart": ( "use six.moves.email_mime_nonmultipart as" + " a drop-in replacement" ), "email.MIMEText": "use six.moves.email_mime_text as a drop-in replacement", "FileDialog": "use six.moves.tkinter_filedialog as a drop-in replacement", "fpformat": "removed in Python 3", "ftplib.Netrc": "removed in Python 3", "functools.wraps": "use six.wraps as a drop-in replacement", "gdbm": "use six.moves.dbm_gnu as a drop-in replacement", "htmlentitydefs": "use six.moves.html_entities as a drop-in replacement", "htmllib": "use six.moves.html_parser instead", "HTMLParser": ( "use six.moves.html_parser as a drop-in replacement" + " (except for HTMLParserError)" ), "HTMLParser.HTMLParseError": "removed in Python 3.5+", "httplib": "use six.moves.http_client as a drop-in replacement", "ihooks": "removed in Python 3", "imageop": "removed in Python 3, use PIL/Pillow instead", "imputil": "removed in Python 3", "inspect.getmoduleinfo": "moved in Python 3, use inspect.getmodulename instead", "itertools.ifilter": "use six.moves.filter as a drop-in replacement", "itertools.ifilterfalse": "use six.moves.filterfalse as a drop-in replacement", "itertools.imap": "use six.moves.map as a drop-in replacement", "itertools.izip": "use six.moves.zip as a drop-in replacement", "itertools.izip_longest": "use six.moves.zip_longest as a drop-in replacement", "linuxaudiodev": "moved in Python 3, use ossaudiodev instead", "markupbase": "moved in Python 3, use _markupbase instead", "md5": "removed in Python 3, use hashlib.md5() instead", "mhlib": "removed in Python 3, use mailbox instead", "mimetools": "moved in Python 3, use email instead", "MimeWriter": "moved in Python 3, use email instead", "mimify": "removed in Python 3, use email instead", "multifile": "removed in Python 3, use email instead", "mutex": "removed in Python 3", "new": "removed in Python 3", "os.getcwd": "use six.moves.getcwdb as a drop-in replacement", "os.getcwdu": "use six.moves.getcwd as a drop-in replacement", "pipes.quote": "use six.moves.shlex_quote as a drop-in replacement", "platform._bcd2str": "removed in Python 3", "platform._mac_ver_gstalt": "removed in Python 3", "platform._mac_ver_lookup": "removed in Python 3", "plistlib.readPlist": "moved in Python 3, use plistlib.load instead", "plistlib.readPlistFromBytes": "moved in Python 3, use plistlib.loads instead", "plistlib.writePlist": "moved in Python 3, use plistlib.dump instead", "plistlib.writePlistToBytes": "moved in Python 3, use plistlib.dumps instead", "popen2": "moved in Python 3, use subprocess instead", "posixfile": "moved in Python 3, use fcntl.lockf instead", "pure": "removed in Python 3", "pydoc.Scanner": "removed in Python 3", "Queue": "use six.moves.queue as a drop-in replacement", "repr": "use six.moves.reprlib as a drop-in replacement", "rexec": "removed in Python 3", "rfc822": "moved in Python 3, use email instead", "robotparser": "use six.moves.urllib.robotparser as a drop-in replacement", "ScrolledText": "use six.moves.tkinter_scrolledtext as a drop-in replacement", "sgmllib": "removed in Python 3", "sha": "moved in Python 3, use hashlib.sha1() instead", "SimpleDialog": "use six.moves.tkinter_simpledialog as a drop-in replacement", "SimpleHTTPServer": "use six.moves.SimpleHTTPServer as a drop-in replacement", "SimpleXMLRPCServer": "use six.moves.xmlrpc_server as a drop-in replacement", "smtplib.SSLFakeFile": "moved in Python 3, use socket.socket.makefile instead", "SocketServer": "use six.moves.socketserver as a drop-in replacement", "sre": "moved in Python 3, use re instead", "statvfs": "moved in Python 3, use os.statvfs instead", "string.atof": "moved in Python 3, use float() as a drop-in replacement", "string.atoi": "moved in Python 3. use int() as a drop-in replacement", "string.atol": "moved in Python 3. use int() as a drop-in replacement", "string.capitalize": "removed in Python 3", "string.center": "removed in Python 3", "string.count": "removed in Python 3", "string.expandtabs": "removed in Python 3", "string.find": "removed in Python 3", "string.index": "removed in Python 3", "string.join": "removed in Python 3", "string.joinfields": "removed in Python 3", "string.letters": ( "moved in Python 3, use string.ascii_letters as a" + " drop-in replacement" ), "string.ljust": "removed in Python 3", "string.lower": "removed in Python 3", "string.lowercase": ( "moved in Python 3, use string.ascii_lowercase as" + " a drop-in replacement" ), "string.lstrip": "removed in Python 3", "string.maketrans": ( "moved in Python 3, use bytes.maketrans or" + " bytearray.maketrans or a dict of unicode codepoints to" + " substitutions instead" ), "string.replace": "removed in Python 3", "string.rfind": "removed in Python 3", "string.rindex": "removed in Python 3", "string.rjust": "removed in Python 3", "string.rsplit": "removed in Python 3", "string.rstrip": "removed in Python 3", "string.split": "removed in Python 3", "string.splitfields": "removed in Python 3", "string.strip": "removed in Python 3", "string.swapcase": "removed in Python 3", "string.translate": "removed in Python 3", "string.upper": "removed in Python 3", "string.uppercase": ( "moved in Python 3, use string.ascii_uppercase as a drop-in replacement" ), "string.zfill": "removed in Python 3", "StringIO": "moved in Python 3, use io.StringIO or io.BytesIO instead", "stringold": "removed in Python 3", "sunaudio": "removed in Python 3", "sv": "removed in Python 3", "tarfile.S_IFBLK": ( "moved in Python 3, use stat.S_IFBLK as a drop-in replacement" ), "tarfile.S_IFCHR": ( "moved in Python 3, use stat.S_IFCHR as a drop-in replacement" ), "tarfile.S_IFDIR": ( "moved in Python 3, use stat.S_IFDIR as a drop-in replacement" ), "tarfile.S_IFIFO": ( "moved in Python 3, use stat.S_IFIFO as a drop-in replacement" ), "tarfile.S_IFLNK": ( "moved in Python 3, use stat.S_IFLNK as a drop-in replacement" ), "tarfile.S_IFREG": ( "moved in Python 3, use stat.S_IFREG as a drop-in replacement" ), "test.test_support": "moved in Python 3, use test.support instead", "test.testall": "removed in Python 3", "thread": "moved in Python 3, use six.moves._thread as a drop-in replacement", "time.accept2dyear": "removed in Python 3", "timing": "moved in Python 3, use time.clock instead", "Tix": "use six.moves.tkinter_tix as a drop-in replacement", "tkColorChooser": "use six.moves.tkinter_colorchooser as a drop-in replacement", "tkCommonDialog": "use six.moves.tkinter_commondialog as a drop-in replacement", "Tkconstants": "use six.moves.tkinter_constants as a drop-in replacement", "Tkdnd": "use six.moves.tkinter_dnd as a drop-in replacement", "tkFileDialog": "use six.moves.tkinter_tkfiledialog as a drop-in replacement", "tkFont": "use six.moves.tkinter_font as a drop-in replacement", "Tkinter": "use six.moves.tkinter as a drop-in replacement", "tkMessageBox": "use six.moves.tkinter_messagebox as a drop-in replacement", "tkSimpleDialog": ( "use six.moves.tkinter_tksimpledialog as a drop-in replacement" ), "toaiff": "removed in Python 3", "ttk": "use six.moves.tkinter_ttk as a drop-in replacement", "types.BooleanType": "moved in Python 3, use bool as a drop-in replacement", "types.BufferType": "removed in Python 3", "types.ClassType": "removed in Python 3", "types.ComplexType": "moved in Python 3, use complex as a drop-in replacement", "types.DictionaryType": "removed in Python 3", "types.DictProxyType": "removed in Python 3", "types.DictType": "moved in Python 3, use dict as a drop-in replacement", "types.EllipsisType": ( "moved in Python 3, use type(Ellipsis) as a drop-in replacement" ), "types.FileType": "removed in Python 3", "types.FloatType": "moved in Python 3, use float as a drop-in replacement", "types.InstanceType": "removed in Python 3", "types.IntType": "use six.integer_types as a drop-in replacement", "types.ListType": "moved in Python 3, use list as a drop-in replacement", "types.LongType": "removed in Python 3", "types.NoneType": "moved in Python 3, use type(None) as a drop-in replacement", "types.NotImplementedType": "removed in Python 3", "types.ObjectType": "removed in Python 3", "types.SliceType": "removed in Python 3", "types.StringType": ( "use six.binary_types or six.text_types, depending on context, instead" ), "types.StringTypes": "use six.string_types as a drop-in replacement", "types.TupleType": "moved in Python 3, use tuple as a drop-in replacement", "types.TypeType": "use six.class_types as a drop-in replacement", "types.UnboundMethodType": "removed in Python 3", "types.UnicodeType": "use six.text_type as a drop-in replacement", "types.XRangeType": "removed in Python 3", "urllib.ContentTooShortError": ( "use six.moves.urllib.error.ContentTooShortError as a drop-in replacement" ), "urllib.FancyURLopener": ( "use six.moves.urllib.request.FancyURLopener as a drop-in replacement" ), "urllib.getproxies": ( "use six.moves.urllib.request.getproxies as a drop-in replacement" ), "urllib.pathname2url": ( "use six.moves.urllib.request.pathname2url as a drop-in replacement" ), "urllib.proxy_bypass": ( "use six.moves.urllib.request.proxy_bypass as a drop-in replacement" ), "urllib.quote": "use six.moves.urllib.parse.quote as a drop-in replacement", "urllib.quote_plus": ( "use six.moves.urllib.parse.quote_plus as a drop-in replacement" ), "urllib.splitattr": "moved in Python 3, use urllib.parse.splitattr instead", "urllib.splithost": "moved in Python 3, use urllib.parse.splithost instead", "urllib.splitnport": "moved in Python 3, use urllib.parse.splitnport instead", "urllib.splitpasswd": "moved in Python 3, use urllib.parse.splitpasswd instead", "urllib.splitport": "moved in Python 3, use urllib.parse.splitport instead", "urllib.splitquery": ( "use six.moves.urllib.parse.splitquery as a drop-in replacement" ), "urllib.splittag": ( "use six.moves.urllib.parse.splittag as a drop-in replacement" ), "urllib.splittype": "moved in Python 3, use urllib.parse.splittype instead", "urllib.splituser": ( "use six.moves.urllib.parse.splituser as a drop-in replacement" ), "urllib.splitvalue": "moved in Python 3, use urllib.parse.splitvalue instead", "urllib.unquote": "use six.moves.urllib.parse.unquote as a drop-in replacement", "urllib.unquote_plus": ( "use six.moves.urllib.parse.unquote_plus as a drop-in replacement" ), "urllib.url2pathname": ( "use six.moves.urllib.request.url2pathname as a drop-in replacement" ), "urllib.urlcleanup": ( "use six.moves.urllib.request.urlcleanup as a drop-in replacement" ), "urllib.urlencode": ( "use six.moves.urllib.parse.urlencode as a drop-in replacement" ), "urllib.URLopener": ( "use six.moves.urllib.request.URLopener as a drop-in replacement" ), "urllib.urlretrieve": ( "use six.moves.urllib.request.urlretrieve as a drop-in replacement" ), "urllib2": "use six.moves.urllib instead", "urllib2.AbstractBasicAuthHandler": ( "use six.moves.urllib.request.AbstractBasicAuthHandler as a" + " drop-in replacement" ), "urllib2.AbstractDigestAuthHandler": ( "use six.moves.urllib.request.AbstractDigestAuthHandler as a" + " drop-in replacement" ), "urllib2.BaseHandler": ( "use six.moves.urllib.request.BaseHandler as a drop-in replacement" ), "urllib2.build_opener": ( "use six.moves.urllib.request.build_opener as a drop-in replacement" ), "urllib2.CacheFTPHandler": ( "use six.moves.urllib.request.CacheFTPHandler as a drop-in replacement" ), "urllib2.FileHandler": ( "use six.moves.urllib.request.FileHandler as a drop-in replacement" ), "urllib2.FTPHandler": ( "use six.moves.urllib.request.FTPHandler as a drop-in replacement" ), "urllib2.HTTPBasicAuthHandler": ( "use six.moves.urllib.request.HTTPBasicAuthHandler as a drop-in replacement" ), "urllib2.HTTPCookieProcessor": ( "use six.moves.urllib.request.HTTPCookieProcessor as a drop-in replacement" ), "urllib2.HTTPDefaultErrorHandler": ( "use six.moves.urllib.request.HTTPDefaultErrorHandler as a drop-in" + " replacement" ), "urllib2.HTTPDigestAuthHandler": ( "use six.moves.urllib.request.HTTPDigestAuthHandler as a drop-in" + " replacement" ), "urllib2.HTTPError": ( "use six.moves.urllib.error.HTTPError as a drop-in replacement" ), "urllib2.HTTPErrorProcessor": ( "use six.moves.urllib.request.HTTPErrorProcessor as a drop-in replacement" ), "urllib2.HTTPHandler": ( "use six.moves.urllib.request.HTTPHandler as a drop-in replacement" ), "urllib2.HTTPPasswordMgr": ( "use six.moves.urllib.request.HTTPPasswordMgr as a drop-in replacement" ), "urllib2.HTTPPasswordMgrWithDefaultRealm": ( "use six.moves.urllib.request.HTTPPasswordMgrWithDefaultRealm as" + " a drop-in replacement" ), "urllib2.HTTPRedirectHandler": ( "use six.moves.urllib.request.HTTPRedirectHandler as a drop-in replacement" ), "urllib2.HTTPSHandler": ( "use six.moves.urllib.request.HTTPSHandler as a drop-in replacement" ), "urllib2.install_opener": ( "use six.moves.urllib.request.install_opener as a drop-in replacement" ), "urllib2.OpenerDirector": ( "use six.moves.urllib.request.OpenerDirector as a drop-in replacement" ), "urllib2.ProxyBasicAuthHandler": ( "use six.moves.urllib.request.ProxyBasicAuthHandler as a drop-in" + " replacement" ), "urllib2.ProxyDigestAuthHandler": ( "use six.moves.urllib.request.ProxyDigestAuthHandler as a drop-in" + " replacement" ), "urllib2.ProxyHandler": ( "use six.moves.urllib.request.ProxyHandler as a drop-in replacement" ), "urllib2.quote": "use six.moves.urllib.parse.quote as a drop-in replacement", "urllib2.Request": ( "use six.moves.urllib.request.Request as a drop-in replacement" ), "urllib2.UnknownHandler": ( "use six.moves.urllib.request.UnknownHandler as a drop-in replacement" ), "urllib2.unquote": ( "use six.moves.urllib.parse.unquote as a drop-in replacement" ), "urllib2.URLError": ( "use six.moves.urllib.error.URLError as a drop-in replacement" ), "urllib2.urlopen": ( "use six.moves.urllib.request.urlopen as a drop-in replacement" ), "urlparse": "use six.moves.urllib.parse as a drop-in replacement", "urlparse.scheme_chars": "moved in Python 3, use urllib.parse.scheme_chars", "user": "removed in Python 3", "UserDict": ( "moved in Python 3, use dict or collections.UserDict or" + " collections.MutableMapping instead" ), "UserDict.UserDict": ( "moved in Python 3, use six.moves.UserDict as a drop-in replacement" ), "UserDict.UserDictMixin": ( "moved in Python 3, use collections.MutableMapping instead" ), "UserList": ( "moved in Python 3, use list or collections.UserList or" + " collections.MutableSequence instead" ), "UserList.UserList": "use six.moves.UserList as a drop-in replacement", "UserString": ( "moved in Python 3, use six.text_type, six.binary_type or" + " collections.UserString instead" ), "UserString.UserString": "use six.moves.UserString as a drop-in replacement", "xmlrpclib": "use six.moves.xmlrpc_client as a drop-in replacement", }