pycram.helper

Implementation of helper functions and classes for internal usage only.

Functions: _block – wrap multiple statements into a single block.

Classes: GeneratorList – implementation of generator list wrappers.

Module Contents

Classes

bcolors	Color codes which can be used to highlight Text in the Terminal. For example,
GeneratorList	Implementation of generator list wrappers.

Functions

_apply_ik(→ None)	Apllies a list of joint poses calculated by an inverse kinematics solver to a robot
calculate_wrist_tool_offset(...)
transform(pose, transformation[, local_coords])
axis_angle_to_quaternion(→ typing_extensions.Tuple)	Convert axis-angle to quaternion.
multiply_quaternions(→ typing_extensions.List)	Multiply two quaternions using the robotics convention (x, y, z, w).
quaternion_rotate(→ typing_extensions.List)	Rotate a vector v using quaternion q.
multiply_poses(→ typing_extensions.Tuple)	Multiply two poses.

class pycram.helper.bcolors

Color codes which can be used to highlight Text in the Terminal. For example, for warnings. Usage: Firstly import the class into the file. print(f’{bcolors.WARNING} Some Text {bcolors.ENDC}’)

HEADER = '\x1b[95m'

OKBLUE = '\x1b[94m'

OKCYAN = '\x1b[96m'

OKGREEN = '\x1b[92m'

WARNING = '\x1b[93m'

FAIL = '\x1b[91m'

ENDC = '\x1b[0m'

BOLD = '\x1b[1m'

UNDERLINE = '\x1b[4m'

pycram.helper._apply_ik(robot: pycram.world_concepts.world_object.Object, joint_poses: typing_extensions.List[float], joints: typing_extensions.List[str]) → None

Apllies a list of joint poses calculated by an inverse kinematics solver to a robot

Parameters:

• robot – The robot the joint poses should be applied on

• joint_poses – The joint poses to be applied

• gripper – specifies the gripper for which the ik solution should be applied

Returns:

None

pycram.helper.calculate_wrist_tool_offset(wrist_frame: str, tool_frame: str, robot: pycram.world_concepts.world_object.Object) → pycram.datastructures.pose.Transform

pycram.helper.transform(pose: typing_extensions.List[float], transformation: typing_extensions.List[float], local_coords=False)

class pycram.helper.GeneratorList(generator: typing_extensions.Callable)

Implementation of generator list wrappers.

Generator lists store the elements of a generator, so these can be fetched multiple times.

Methods: get – get the element at a specific index. has – check if an element at a specific index exists.

Create a new generator list.

Arguments: generator – the generator to use.

get(index: int = 0)

Get the element at a specific index or raise StopIteration if it doesn’t exist.

Arguments: index – the index to get the element of.

has(index: int) → bool

Check if an element at a specific index exists and return True or False.

Arguments: index – the index to check for.

pycram.helper.axis_angle_to_quaternion(axis: typing_extensions.List, angle: float) → typing_extensions.Tuple

Convert axis-angle to quaternion.

Parameters:

• axis – (x, y, z) tuple representing rotation axis.

• angle – rotation angle in degree

Returns:

The quaternion representing the axis angle

pycram.helper.multiply_quaternions(q1: typing_extensions.List, q2: typing_extensions.List) → typing_extensions.List

Multiply two quaternions using the robotics convention (x, y, z, w).

Parameters:

• q1 – The first quaternion

• q2 – The second quaternion

Returns:

The quaternion resulting from the multiplication

pycram.helper.quaternion_rotate(q: typing_extensions.List, v: typing_extensions.List) → typing_extensions.List

Rotate a vector v using quaternion q.

Parameters:

• q – A quaternion of how v should be rotated

• v – A vector that should be rotated by q

Returns:

V rotated by Q as a quaternion

pycram.helper.multiply_poses(pose1: pycram.datastructures.pose.Pose, pose2: pycram.datastructures.pose.Pose) → typing_extensions.Tuple

Multiply two poses.

Parameters:

• pose1 – first Pose that should be multiplied

• pose2 – Second Pose that should be multiplied

Returns:

A Tuple of position and quaternion as result of the multiplication