class Index

def clone(self)

Create a copy of this Index.

    def clone(self):
        """Create a copy of this Index."""
        _, args, kwargs = self.deconstruct()
        return self.__class__(*args, **kwargs)

def contains_expressions(self)

def create_sql(self, model, schema_editor, using='', **kwargs)

    def create_sql(self, model, schema_editor, using="", **kwargs):
        include = [
            model._meta.get_field(field_name).column for field_name in self.include
        ]
        condition = self._get_condition_sql(model, schema_editor)
        if self.expressions:
            index_expressions = []
            for expression in self.expressions:
                index_expression = IndexExpression(expression)
                index_expression.set_wrapper_classes(schema_editor.connection)
                index_expressions.append(index_expression)
            expressions = ExpressionList(*index_expressions).resolve_expression(
                Query(model, alias_cols=False),
            )
            fields = None
            col_suffixes = None
        else:
            fields = [
                model._meta.get_field(field_name)
                for field_name, _ in self.fields_orders
            ]
            if schema_editor.connection.features.supports_index_column_ordering:
                col_suffixes = [order[1] for order in self.fields_orders]
            else:
                col_suffixes = [""] * len(self.fields_orders)
            expressions = None
        return schema_editor._create_index_sql(
            model,
            fields=fields,
            name=self.name,
            using=using,
            db_tablespace=self.db_tablespace,
            col_suffixes=col_suffixes,
            opclasses=self.opclasses,
            condition=condition,
            include=include,
            expressions=expressions,
            **kwargs,
        )

def deconstruct(self)

    def deconstruct(self):
        path = "%s.%s" % (self.__class__.__module__, self.__class__.__name__)
        path = path.replace("django.db.models.indexes", "django.db.models")
        kwargs = {"name": self.name}
        if self.fields:
            kwargs["fields"] = self.fields
        if self.db_tablespace is not None:
            kwargs["db_tablespace"] = self.db_tablespace
        if self.opclasses:
            kwargs["opclasses"] = self.opclasses
        if self.condition:
            kwargs["condition"] = self.condition
        if self.include:
            kwargs["include"] = self.include
        return (path, self.expressions, kwargs)

def remove_sql(self, model, schema_editor, **kwargs)

    def remove_sql(self, model, schema_editor, **kwargs):
        return schema_editor._delete_index_sql(model, self.name, **kwargs)

def set_name_with_model(self, model)

Generate a unique name for the index.

The name is divided into 3 parts - table name (12 chars), field name
(8 chars) and unique hash + suffix (10 chars). Each part is made to
fit its size by truncating the excess length.

    def set_name_with_model(self, model):
        """
        Generate a unique name for the index.

        The name is divided into 3 parts - table name (12 chars), field name
        (8 chars) and unique hash + suffix (10 chars). Each part is made to
        fit its size by truncating the excess length.
        """
        _, table_name = split_identifier(model._meta.db_table)
        column_names = [
            model._meta.get_field(field_name).column
            for field_name, order in self.fields_orders
        ]
        column_names_with_order = [
            (("-%s" if order else "%s") % column_name)
            for column_name, (field_name, order) in zip(
                column_names, self.fields_orders
            )
        ]
        # The length of the parts of the name is based on the default max
        # length of 30 characters.
        hash_data = [table_name] + column_names_with_order + [self.suffix]
        self.name = "%s_%s_%s" % (
            table_name[:11],
            column_names[0][:7],
            "%s_%s" % (names_digest(*hash_data, length=6), self.suffix),
        )
        if len(self.name) > self.max_name_length:
            raise ValueError(
                "Index too long for multiple database support. Is self.suffix "
                "longer than 3 characters?"
            )
        if self.name[0] == "_" or self.name[0].isdigit():
            self.name = "D%s" % self.name[1:]