rclpy.parameter module

class rclpy.parameter.Parameter(name: str, type_: Type | None = None)
class rclpy.parameter.Parameter(name: str, type_: Type, value: AllowableParameterValueT)
class rclpy.parameter.Parameter(name: str, *, value: AllowableParameterValueT)

Bases: Generic[AllowableParameterValueT]

class Type(value, names=<not given>, *values, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: IntEnum

check(parameter_value: AllowableParameterValueT) → bool
classmethod from_parameter_value(parameter_value: AllowableParameterValueT) → Type

Get a Parameter.Type from a given variable.

Returns:

A Parameter.Type corresponding to the instance type of the given value.

Raises:

TypeError if the conversion to a type was not possible.

classmethod from_parameter_msg(param_msg: rcl_interfaces.msg.Parameter) → Parameter[AllowableParameterValueT]
get_parameter_value() → rcl_interfaces.msg.ParameterValue
property name: str
to_parameter_msg() → rcl_interfaces.msg.Parameter
property type_: Type
property value: AllowableParameterValueT
rclpy.parameter.get_parameter_value(string_value: str) → rcl_interfaces.msg.ParameterValue

Guess the desired type of the parameter based on the string value.

Parameters:

string_value – The string value to be converted to a ParameterValue.

Returns:

The ParameterValue.

rclpy.parameter.parameter_dict_from_yaml_file(parameter_file: str, use_wildcard: bool = False, target_nodes: List[str] | None = None, namespace: str = '') → Dict[str, rcl_interfaces.msg.Parameter]

Build a dict of parameters from a YAML file.

Will load all parameters if target_nodes is None or empty.

Raises:

  • RuntimeError – if a target node is not in the file

  • RuntimeError – if the is not a valid ROS parameter file

Parameters:

  • parameter_file – Path to the YAML file to load parameters from.

  • use_wildcard – Use wildcard matching for the target nodes.

  • target_nodes – List of nodes in the YAML file to load parameters from.

  • namespace – Namespace to prepend to all parameters.

Returns:

A dict of Parameter messages keyed by the parameter names

rclpy.parameter.parameter_value_to_python(parameter_value: rcl_interfaces.msg.ParameterValue) → Any

Get the value for the Python builtin type from a rcl_interfaces/msg/ParameterValue object.

Returns the value member of the message based on the type member. Returns None if the parameter is “NOT_SET”.

Parameters:

parameter_value – The message to get the value from.

Raises:

RuntimeError – if the member type has an unexpected value.