checker.py 文件源码

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 = all_names.difference(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:
                    for binding in scope.values():
                        if isinstance(binding, StarImportation):
                            binding.used = all_binding

            # 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), ast.For):
                            messg = messages.ImportShadowedByLoopVar
                        elif used:
                            continue
                        else:
                            messg = messages.RedefinedWhileUnused
                        self.report(messg, node, value.name, value.source)