py_trees.utilities module

Assorted utility functions.

class py_trees.utilities.Process(*args: Any, **kwargs: Any)

Bases: Process

Convenience wrapper around multiprocessing.Process.

property exception: Any

Check the connection, if there is an error, reflect it as an exception.

Returns:

The exception.

run() → None

Start the process, handle exceptions if needed.

py_trees.utilities.get_fully_qualified_name(instance: object) → str

Retrieve the fully qualified name of an object.

For example, an instance of Sequence becomes ‘py_trees.composites.Sequence’.

Args:

instance (object): an instance of any class

Returns:

str: the fully qualified name

py_trees.utilities.get_valid_filename(s: str) → str

Clean up and style a string so that it can be used as a filename.

This is valid only from the perspective of the py_trees package. It does place a few extra constraints on strings to keep string handling and manipulation complexities to a minimum so that sanity prevails.

• Removes leading and trailing spaces

• Convert other spaces and newlines to underscores

• Remove anything that is not an alphanumeric, dash, underscore, or dot

>>> utilities.get_valid_filename("john's portrait in 2004.jpg")
'johns_portrait_in_2004.jpg'

Args:

program (str): string to convert to a valid filename

Returns:

str: a representation of the specified string as a valid filename

py_trees.utilities.is_primitive(incoming: Any) → bool

Check if an incoming argument is a primitive type with no esoteric accessors.

That is, it has no class attributes or container style [] accessors.

Args:

incoming: the instance to check

Returns:

True or false, depending on the check against the reserved primitives

py_trees.utilities.static_variables(**kwargs: Any) → Callable[[C], C]

Attach initialised static variables to a python method.

@static_variables(counter=0)
def foo():
    foo.counter += 1
    print("Counter: {}".format(foo.counter))

py_trees.utilities.truncate(original: str, length: int) → str

Provide an elided (…) version of a string if it is longer than desired.

Args:

original: string to elide length: constrain the elided string to this

py_trees.utilities.which(program: str) → str | None

Call the command line ‘which’ tool (convenience wrapper).

Args:

program: name of the program to find.

Returns:

path to the program or None if it doesnt exist.