jinja2.nodes.Const

class documentation

class Const(Literal): (source)

All constant values. The parser will return this node for simple constants such as ``42`` or ``"foo"`` but it can be used to store more complex values such as lists too. Only constants with a safe representation (objects where ``eval(repr(x)) == x`` is true).

Class Method	`from_untrusted`	Return a const object if the value is representable as constant value in the generated code, otherwise it will raise an `Impossible` exception.
Method	`as_const`	Return the value of the expression as constant or raise :exc:`Impossible` if this was not possible.
Class Variable	`fields`	Undocumented
Class Variable	`value`	Undocumented

Inherited from Literal:

Class Variable abstract Undocumented

Inherited from Expr (via Literal):

Method can_assign Check if it's possible to assign something to this node.

Inherited from Node (via Literal, Expr):

Method	`__eq__`	Undocumented
Method	`__init__`	Undocumented
Method	`__repr__`	Undocumented
Method	`dump`	Undocumented
Method	`find`	Find the first node of a given type. If no such node exists the return value is `None`.
Method	`find_all`	Find all the nodes of a given type. If the type is a tuple, the check is performed for any of the tuple items.
Method	`iter_child_nodes`	Iterates over all direct child nodes of the node. This iterates over all fields and yields the values of they are nodes. If the value of a field is a list all the nodes in that list are returned.
Method	`iter_fields`	This method iterates over all fields that are defined and yields ``(key, value)`` tuples. Per default all fields are returned, but it's possible to limit that to some fields by providing the `only` parameter or to exclude some using the `exclude` parameter...
Method	`set_ctx`	Reset the context of a node and all child nodes. Per default the parser will all generate nodes that have a 'load' context as it's the most common one. This method is used in the parser to set assignment targets and other nodes to a store context.
Method	`set_environment`	Set the environment for all nodes.
Method	`set_lineno`	Set the line numbers of the node and children.
Class Variable	`attributes`	Undocumented
Class Variable	`environment`	Undocumented
Class Variable	`lineno`	Undocumented

@classmethod
def from_untrusted(cls, value, lineno=None, environment=None): (source)

Return a const object if the value is representable as constant value in the generated code, otherwise it will raise an `Impossible` exception.

Parameters
value:`t.Any`	Undocumented
lineno:`t.Optional[int]`	Undocumented
environment:`t.Optional[Environment]`	Undocumented
Returns
`Const`	Undocumented

def as_const(self, eval_ctx=None): (source)

overrides jinja2.nodes.Expr.as_const

Return the value of the expression as constant or raise :exc:`Impossible` if this was not possible. An :class:`EvalContext` can be provided, if none is given a default context is created which requires the nodes to have an attached environment. .. versionchanged:: 2.4 the `eval_ctx` parameter was added.

Parameters
eval_ctx:`t.Optional[EvalContext]`	Undocumented
Returns
`t.Any`	Undocumented

fields: tuple[str, ...] = (source)

overrides jinja2.nodes.Node.fields

Undocumented

value: t.Any = (source)

Undocumented