#!/usr/bin/env python
#
# License: BSD
# https://raw.githubusercontent.com/splintered-reality/py_trees/devel/LICENSE
#
##############################################################################
# Documentation
##############################################################################
"""
Assorted utility functions.
"""
##############################################################################
# Imports
##############################################################################
import multiprocessing
import os
import re
import traceback
##############################################################################
# Python Helpers
##############################################################################
[docs]def static_variables(**kwargs):
"""
This is a decorator that can be used with python methods to attach
initialised static variables to the method.
.. code-block:: python
@static_variables(counter=0)
def foo():
foo.counter += 1
print("Counter: {}".format(foo.counter))
"""
def decorate(func):
for k in kwargs:
setattr(func, k, kwargs[k])
return func
return decorate
[docs]def truncate(original: str, length: int) -> str:
"""
Provide an elided version of the string for which the last three
characters are dots if the original string does not fit within the
specified length.
Args:
original: string to elide
length: constrain the elided string to this
"""
s = (original[:length - 3] + '...') if len(original) > length else original
return s
##############################################################################
# System Tools
##############################################################################
[docs]class Process(multiprocessing.Process):
def __init__(self, *args, **kwargs):
multiprocessing.Process.__init__(self, *args, **kwargs)
self._pconn, self._cconn = multiprocessing.Pipe()
self._exception = None
[docs] def run(self):
try:
multiprocessing.Process.run(self)
self._cconn.send(None)
except Exception as e:
tb = traceback.format_exc()
self._cconn.send((e, tb))
@property
def exception(self):
if self._pconn.poll():
self._exception = self._pconn.recv()
return self._exception
[docs]def which(program):
'''
Wrapper around the command line 'which' program.
Args:
program (:obj:`str`): name of the program to find.
Returns:
:obj:`str`: path to the program or None if it doesnt exist.
'''
def is_exe(fpath):
return os.path.isfile(fpath) and os.access(fpath, os.X_OK)
fpath, unused_fname = os.path.split(program)
if fpath:
if is_exe(program):
return program
else:
for path in os.environ["PATH"].split(os.pathsep):
path = path.strip('"')
exe_file = os.path.join(path, program)
if is_exe(exe_file):
return exe_file
return None
[docs]def get_valid_filename(s: str) -> str:
"""
Return the given string converted to a string that can be used for a clean
filename (without extension). Remove leading and trailing spaces; convert
other spaces and newlines to underscores; and remove anything that is not
an alphanumeric, dash, underscore, or dot.
.. code-block:: python
>>> utilities.get_valid_filename("john's portrait in 2004.jpg")
'johns_portrait_in_2004.jpg'
Args:
program (:obj:`str`): string to convert to a valid filename
Returns:
:obj:`str`: a representation of the specified string as a valid filename
"""
s = str(s).strip().lower().replace(' ', '_').replace('\n', '_')
return re.sub(r'(?u)[^-\w.]', '', s)
[docs]def get_fully_qualified_name(instance: object) -> str:
"""
Get at the fully qualified name of an object, e.g.
an instance of a :class:`~py_trees.composites.Sequence`
becomes 'py_trees.composites.Sequence'.
Args:
instance (:obj:`object`): an instance of any class
Returns:
:obj:`str`: the fully qualified name
"""
module = instance.__class__.__module__
# if there is no module, it will report builtin, get that
# string via what should remain constant, the 'str' class
# and check against that.
builtin = str.__class__.__module__
if module is None or module == builtin:
return instance.__class__.__name__
else:
return module + '.' + instance.__class__.__name__