Lint fixes on benchmarks and examples/*.py by roryyorke · Pull Request #1135

Lint fixes on benchmarks and examples/*.py by roryyorke · Pull Request #1135 · python-control/python-control

I don't think these are too controversial.

CI failures

I see two failures on CI , but I can't see that these changes caused them:

first, in doctest-linux: https://github.com/roryyorke/python-control/actions/runs/13612156165/job/38050709282

Traceback
=========

      File "/home/runner/miniconda3/envs/doctest-env/lib/python3.12/site-packages/sphinx/events.py", line 415, in emit
        raise ExtensionError(
    sphinx.errors.ExtensionError: Handler <function html_collect_pages at 0x7f36a35016c0> for event 'html-collect-pages' threw an exception (exception: module 'sphinx.util' has no attribute 'console')

which seems to be sphinx-doc/sphinx#13352.

Then in install-examples: https://github.com/roryyorke/python-control/actions/runs/13612156159/job/38050709274

ModuleNotFoundError: No module named 'autoreload'

I'll install jupyterlab in my dev environment and see if I can reproduce this. I can't see that changing *.py files in examples could cause this.

tfvis.py and Pwm Pmw

When I ran tfvis.py under Python 3.12, I got

AttributeError: module 'collections' has no attribute 'Callable'

in ~~Pwm~~ Pmw code.

Callable was moved to collections.abc in Python 3.10 (October 2021). The hack below lets the script run, but unless ~~pwm~~ Pmw is updated we should consider retiring this example.

modified   examples/tfvis.py
@@ -48,6 +48,9 @@ from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
 from control.matlab import logspace
 from numpy import array, conj, polymul, real, size
 
+import collections.abc
+collections.Callable = collections.abc.Callable
+
 
 def make_poly(facts):
     """ Create polynomial from factors """

Warnings in examples

Some examples raise control deprecation warnings, e.g., genswitch.py uses phase_plot instead of phase_plane_plot. I started looking into this, but it got a bit involved.

Lint on notebooks

ruff can also run on Jupyter notebooks. Some fixes are obvious:

examples/bode-and-nyquist-plots.ipynb:cell 2:2:17: F401 [*] `scipy` imported but unused
  |
1 | import numpy as np
2 | import scipy as sp
  |                 ^^ F401
3 | import matplotlib.pyplot as plt
4 | import control as ct
  |
  = help: Remove unused import: `scipy`

but I'm less sure about changing these * imports; they are convenient, and make things more familiar for Matlab users:

examples/pvtol-lqr-nested.ipynb:cell 3:2:1: F403 `from matplotlib.pyplot import *` used; unable to detect undefined names
  |
1 | from numpy import *             # Grab all of the NumPy functions
2 | from matplotlib.pyplot import * # Grab MATLAB plotting functions
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ F403
3 | from control.matlab import *    # MATLAB-like functions
4 | %matplotlib inline
  |