How to use the pyflakes.messages.ImportShadowedByLoopVar function in pyflakes

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.parent):
        for scope in self.scopeStack[::-1]:
            if value.name in scope:
                break
        existing = scope.get(value.name)

        if existing and not self.differentForks(node, existing.source):

            parent_stmt = self.getParent(value.source)
            if isinstance(existing, Importation) and isinstance(parent_stmt, ast.For):
                self.report(messages.ImportShadowedByLoopVar,
                            node, value.name, existing.source)

            elif scope is self.scope:
                if (isinstance(parent_stmt, ast.comprehension) and
                        not isinstance(self.getParent(existing.source),
                                       (ast.For, ast.comprehension))):
                    self.report(messages.RedefinedInListComp,
                                node, value.name, existing.source)
                elif not existing.used and value.redefines(existing):
                    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:

for name in undefined:
                        self.report(messages.UndefinedExport,
                                    scope['__all__'].source, name)
            else:
                all_names = []

            # 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, value.name)
                    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)

vars = []
        def collectLoopVars(n):
            if isinstance(n, _ast.Name):
                vars.append(n.id)
            elif isinstance(n, _ast.expr_context):
                return
            else:
                for c in iter_child_nodes(n):
                    collectLoopVars(c)

        collectLoopVars(node.target)
        for varn in vars:
            if (isinstance(self.scope.get(varn), Importation)
                    # unused ones will get an unused import warning
                    and self.scope[varn].used):
                self.report(messages.ImportShadowedByLoopVar,
                            node, varn, self.scope[varn].source)

        self.handleChildren(node)

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.parent):
        for scope in self.scopeStack[::-1]:
            if value.name in scope:
                break
        existing = scope.get(value.name)

        if existing and not self.differentForks(node, existing.source):

            parent_stmt = self.getParent(value.source)
            if isinstance(existing, Importation) and isinstance(parent_stmt, ast.For):
                self.report(messages.ImportShadowedByLoopVar,
                            node, value.name, existing.source)

            elif scope is self.scope:
                if (isinstance(parent_stmt, ast.comprehension) and
                        not isinstance(self.getParent(existing.source),
                                       (ast.For, ast.comprehension))):
                    self.report(messages.RedefinedInListComp,
                                node, value.name, existing.source)
                elif not existing.used and value.redefines(existing):
                    self.report(messages.RedefinedWhileUnused,
                                node, value.name, existing.source)

            elif isinstance(existing, Importation) and value.redefines(existing):
                existing.redefined.append(node)

        self.scope[value.name] = 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.parent):
        for scope in self.scopeStack[::-1]:
            if value.name in scope:
                break
        existing = scope.get(value.name)

        if existing and not self.differentForks(node, existing.source):

            parent_stmt = self.getParent(value.source)
            if isinstance(existing, Importation) and isinstance(parent_stmt, ast.For):
                self.report(messages.ImportShadowedByLoopVar,
                            node, value.name, existing.source)

            elif scope is self.scope:
                if (isinstance(parent_stmt, ast.comprehension) and
                        not isinstance(self.getParent(existing.source),
                                       (ast.For, ast.comprehension))):
                    self.report(messages.RedefinedInListComp,
                                node, value.name, existing.source)
                elif not existing.used and value.redefines(existing):
                    self.report(messages.RedefinedWhileUnused,
                                node, value.name, existing.source)

            elif isinstance(existing, Importation) and value.redefines(existing):
                existing.redefined.append(node)

        self.scope[value.name] = value

vars = []
        def collectLoopVars(n):
            if isinstance(n, _ast.Name):
                vars.append(n.id)
            elif isinstance(n, _ast.expr_context):
                return
            else:
                for c in iter_child_nodes(n):
                    collectLoopVars(c)

        collectLoopVars(node.target)
        for varn in vars:
            if (isinstance(self.scope.get(varn), Importation)
                    # unused ones will get an unused import warning
                    and self.scope[varn].used):
                self.report(messages.ImportShadowedByLoopVar,
                            node.lineno, varn, self.scope[varn].source.lineno)

        self.handleChildren(node)

for name in undefined:
                        self.report(messages.UndefinedExport,
                                    scope['__all__'].source, name)
            else:
                all_names = []

            # 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, value.name)
                    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)

- `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 (isinstance(parent_stmt, ast.comprehension) and
                        not isinstance(self.getParent(existing.source),
                                       (FOR_TYPES, ast.comprehension))):
                    self.report(messages.RedefinedInListComp,
                                node, value.name, existing.source)
                elif not existing.used and value.redefines(existing):
                    if value.name != '_' or isinstance(existing, Importation):
                        if 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)

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.parent):
        for scope in self.scopeStack[::-1]:
            if value.name in scope:
                break
        existing = scope.get(value.name)

        if existing and not self.differentForks(node, existing.source):

            parent_stmt = self.getParent(value.source)
            if isinstance(existing, Importation) and isinstance(parent_stmt, ast.For):
                self.report(messages.ImportShadowedByLoopVar,
                            node, value.name, existing.source)

            elif scope is self.scope:
                if (isinstance(parent_stmt, ast.comprehension) and
                        not isinstance(self.getParent(existing.source),
                                       (ast.For, ast.comprehension))):
                    self.report(messages.RedefinedInListComp,
                                node, value.name, existing.source)
                elif not existing.used and value.redefines(existing):
                    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:

# 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)