Replace pylint and pycodestyle with ruff. ruff is much faster, and supports a lot more checks. Apply a lot of ruff fixes:

* Fix `RenderTraceBase` name collision and fix some broken tests.
* Delete some unused code and variables.
* Rename some unused variables to `_`.
* Remove some unnecessary calls to `len`.
* Remove unused imports.
* Sort imports.
* Define `__all__` in `__init__.py`.
* Simplify `tox.ini`.

Author: fdxmw

docs/conf.py

@@ -12,6 +12,7 @@
 #
 import os
 import sys
+
 sys.path.insert(0, os.path.abspath('..'))
 
 

examples/example1-combologic.py

@@ -10,6 +10,7 @@
 """
 
 import random
+
 import pyrtl
 
 # The basic idea of PyRTL is to specify the component of a some hardware block

examples/example1.2-wire-struct.py

@@ -8,6 +8,7 @@
 """
 
 import inspect
+
 import pyrtl
 
 # Motivation

examples/example2-counter.py

@@ -8,7 +8,6 @@
 
 import pyrtl
 
-
 # Let's just dive right in.
 
 def one_bit_add(a, b, carry_in):

examples/example3-statemachine.py

@@ -7,6 +7,7 @@
 """
 
 import enum
+
 import pyrtl
 
 token_in = pyrtl.Input(1, 'token_in')

examples/example4-debuggingtools.py

@@ -6,10 +6,11 @@
 PyRTL comes with various features to help you find mistakes.
 """
 
-import random
 import io
-from pyrtl.rtllib import adders, multipliers
+import random
+
 import pyrtl
+from pyrtl.rtllib import adders, multipliers
 
 random.seed(93729473)  # used to make random calls deterministic for this example
 

examples/example5-introspection.py

@@ -2,7 +2,6 @@
 
 import pyrtl
 
-
 # The following example shows how PyRTL can be used to make some interesting
 # hardware structures using Python introspection.  In particular, this example
 # makes a N-stage pipeline structure.  Any specific pipeline is then a derived

examples/example8-verilog.py

@@ -7,8 +7,9 @@
     that make doing netlist-level transforms and analysis directly in PyRTL easy.
 """
 
-import random
 import io
+import random
+
 import pyrtl
 
 # ---- Importing From Verilog ----

examples/example9-transforms-draft.py

@@ -1,10 +1,10 @@
+import random
 
 import pyrtl
 from pyrtl import transform
 
 
 def insert_random_inversions(rate=0.5):
-    import random
 
     def randomly_replace(wire):
         if random.random() < rate:

ipynb-examples/example1-combologic.ipynb

@@ -39,6 +39,7 @@
    "outputs": [],
    "source": [
     "import random\n",
+    "\n",
     "import pyrtl"
    ]
   },