diff --git a/.github/workflows/codespell.yml b/.github/workflows/codespell.yml
index 34f3d2b0..0921c8dd 100644
--- a/.github/workflows/codespell.yml
+++ b/.github/workflows/codespell.yml
@@ -6,7 +6,7 @@ on:  # yamllint disable-line rule:truthy
   pull_request:
 
 jobs:
-  pylint:
+  codespell:
     name: Run Codespell
     runs-on: ubuntu-latest
     steps:
diff --git a/.github/workflows/python_unit_tests.yml b/.github/workflows/python_unit_tests.yml
new file mode 100755
index 00000000..3590cc23
--- /dev/null
+++ b/.github/workflows/python_unit_tests.yml
@@ -0,0 +1,75 @@
+---
+name: python_unit_tests
+
+# Always run on Pull Requests
+on:  # yamllint disable-line rule:truthy
+  pull_request:
+
+jobs:
+  get_files:
+    runs-on: ubuntu-latest
+    outputs:
+      changed_files_list: ${{ steps.get-changed-files.outputs.files }}
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0  # fetch-depth 0 is required for diffing
+
+      - name: Get changed Python files
+        id: get-changed-files
+        run: |
+          # Use git diff to find changed files and format them as a
+          # newline-separated string
+          changed="$(git diff --name-only --diff-filter=ACMRT HEAD~1 HEAD |\
+            grep '.*\.py$' | tr '\n' ' ')"
+          echo "changed files = $changed"
+          # Set the string as a step output
+          echo "files=$changed" >> $GITHUB_OUTPUT
+
+      - name: Display changed files (in the same job)
+        run: |
+          echo "Changed files in this job:"
+          echo "${{ steps.get-changed-files.outputs.files }}"
+        shell: bash
+
+  python_unit_tests:
+    needs: [get_files]
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        # Define additional variables for different target platforms or
+        # configurations
+        target: [x86_64, arm64]
+      # Optional: set fail-fast to false to allow all jobs to complete
+      # even if one fails
+      fail-fast: false
+
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+
+      - name: Set up Python 3
+        uses: actions/setup-python@v5  # Action to set up Python
+        with:
+          cache: 'pip'  # Caches dependencies for faster subsequent runs
+      - name: Install dependencies
+        # The conditional check differs slightly between shells
+        # (Linux/macOS vs. Windows)
+        run: |
+          REQUIREMENTS_FILE="workflow/${{ runner.os }}/requirements.txt"
+          if [ -f "$REQUIREMENTS_FILE" ]; then
+            python -m pip install --upgrade pip
+            pip install -r "$REQUIREMENTS_FILE"
+          fi
+        shell: bash  # Explicitly use bash for consistency on
+        #              Linux/macOS/Windows runners
+      - name: Run unit test script
+        # GitHub VS-CODE plugin false positive
+        run: |
+          files="${{ needs.get_files.outputs.changed_files_list }}"
+          export CHANGED_FILES="$files"
+          ./tests/pre-commit_d/python_unit_tests.sh
+        shell: bash
diff --git a/.github/workflows/shellcheck.yml b/.github/workflows/shellcheck.yml
index 130131e6..52a5b39b 100644
--- a/.github/workflows/shellcheck.yml
+++ b/.github/workflows/shellcheck.yml
@@ -6,7 +6,7 @@ on:  # yamllint disable-line rule:truthy
   pull_request:
 
 jobs:
-  pylint:
+  shellcheck:
     name: Run ShellCheck
     runs-on: ubuntu-latest
     steps:
diff --git a/.github/workflows/xmllint.yml b/.github/workflows/xmllint.yml
index 22ff1e37..1947db19 100644
--- a/.github/workflows/xmllint.yml
+++ b/.github/workflows/xmllint.yml
@@ -6,7 +6,7 @@ on:  # yamllint disable-line rule:truthy
   pull_request:
 
 jobs:
-  pylint:
+  xmllint:
     name: Run Xmllint
     # Oddly ubuntu-latest is older than 22.04 right now.
     runs-on: ubuntu-22.04
diff --git a/d-rats.py b/d-rats.py
index 9b693474..65966435 100755
--- a/d-rats.py
+++ b/d-rats.py
@@ -30,6 +30,7 @@
 import sys
 import traceback
 
+# pylint: disable=import-error
 import gi
 gi.require_version("Gtk", "3.0")
 from gi.repository import Gtk
@@ -59,8 +60,8 @@
 sys.path.insert(0, os.path.join("/usr/share", "d-rats"))
 
 # import module to have spelling correction in chat and email applications
-from d_rats import utils, spell
 
+from d_rats import utils, spell
 spell.get_spell().test()
 
 IGNORE_ALL = False
@@ -88,7 +89,8 @@ def handle_exception(except_type, value, trace_back):
     global IGNORE_ALL
 
     if except_type is KeyboardInterrupt or IGNORE_ALL:
-        return sys.__excepthook__(except_type, value, trace_back)
+        sys.__excepthook__(except_type, value, trace_back)
+        return
 
     # Gdk.pointer_ungrab(Gdk.CURRENT_TIME)
     # Gdk.keyboard_ungrab(Gdk.CURRENT_TIME)
diff --git a/d_rats/dplatform.py b/d_rats/dplatform.py
index 2ff532e8..f11f755b 100755
--- a/d_rats/dplatform.py
+++ b/d_rats/dplatform.py
@@ -22,7 +22,6 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
 import logging
 import os
 import sys
diff --git a/d_rats/dplatform_generic.py b/d_rats/dplatform_generic.py
index ea6b33da..7deb3848 100755
--- a/d_rats/dplatform_generic.py
+++ b/d_rats/dplatform_generic.py
@@ -2,7 +2,7 @@
 #
 # Copyright 2009 Dan Smith <dsmith@danplanet.com>
 # review 2015 Maurizio Andreotti  <iz2lxi@yahoo.it>
-# Copyright 2021-2023 John. E. Malmberg - Python3 Conversion
+# Copyright 2021-2023,2026 John. E. Malmberg - Python3 Conversion
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -37,16 +37,39 @@
         HAVE_AUDIO = True
     except ModuleNotFoundError:
         pass
+else:
+    # This code is mainly to silence the linters when run on a
+    # platform with out sound support, it is actually unreachable.
+    class AudioSegment():
+        '''Mocked class when sound is not available.'''
 
-import urllib.request
-import urllib.parse
-import urllib.error
+        # pylint: disable=no-self-use
+        def from_wav(self, soundfile):
+            '''Mocked method when sound is not available'''
+            print(f'No support for playing {soundfile}')
+
+        @staticmethod
+        def dummy():
+            '''Needs two public methods'''
+
+    def play(sound):
+        '''Mocked routine when sound is not available.'''
+        sound_type = type(sound)
+        print(f'Unable to play sound {sound_type} is unsupported')
 
-import gi  # type: ignore # Needed for pylance on Microsoft Windows
-gi.require_version("Gtk", "3.0")
-from gi.repository import Gtk # type: ignore
-from gi.repository import Gio # type: ignore
 
+import urllib.request
+
+# This version of D-Rats requires GTK 3.0, but not for doing unit
+# tests.   This allows the default unit tests to pass on a system with
+# out GTK+ installed.
+try:
+    import gi
+    gi.require_version("Gtk", "3.0")
+    from gi.repository import Gtk # type: ignore
+    from gi.repository import Gio # type: ignore
+except (ImportError, ValueError):
+    pass
 
 if '_' not in locals():
     import gettext
@@ -176,14 +199,15 @@ def get_exe_path(name):
         :rtype: str
         '''
         # Make trivial check from the normal paths
-        exe_path = shutil.which(name)
+        # known false positive in pylance
+        exe_path = shutil.which(name)  # type: ignore
         if exe_path:
             return exe_path
         programfiles = os.getenv("PROGRAMFILES")
         if programfiles:
             for program in [programfiles, programfiles + " (x86)"]:
                 test_path=os.path.join(program, name)
-                exe_path = shutil.which(name, path=test_path)
+                exe_path = shutil.which(name, path=test_path)  # type: ignore
                 if exe_path:
                     return exe_path
         return None
@@ -261,14 +285,14 @@ def open_html_file(path):
         gio_path = Gio.File.parse_name(path)
         appinfo.launch([gio_path], None)
 
-    @staticmethod
-    def list_serial_ports():
+    def list_serial_ports(self):
         '''
         List Serial Ports.
 
         :returns: empty list
         :rtype: list
         '''
+        self.logger.info("list_serial_ports not available on this platform")
         return []
 
     @staticmethod
@@ -281,9 +305,8 @@ def default_dir():
         '''
         return "."
 
-    @staticmethod
-    # pylint: disable=unused-argument
-    def gui_open_file(mime_types=None, start_dir=None):
+    # pylint: disable=unused-argument, no-self-use
+    def gui_open_file(self, mime_types=None, start_dir=None):
         '''
         GUI Open File.
 
@@ -309,14 +332,14 @@ def gui_open_file(mime_types=None, start_dir=None):
         #    for mime_type in mime_types:
         #        exts = mimetypes.guess_all_extensions(mime_type, strict=True)
         #        filter_mime.set_name=(exts)
-                # In this case it does not seem to matter what string was
-                # passed to the filter, the filter shows up as unnamed.
-                # This issue does not reproduce in a quick test program.
+        # In this case it does not seem to matter what string was
+        # passed to the filter, the filter shows up as unnamed.
+        # This issue does not reproduce in a quick test program.
         #        filter_mime.add_mime_type=(mime_type)
         #        dlg.add_filter(filter_mime)
         #    filter_any = Gtk.FileFilter()
         #    filter_any.set_name(_("All files"))
-            # In this case the filter name gets set prpoerly unlike above.
+        # In this case the filter name gets set properly unlike above.
         #    filter_any.add_pattern=('*')
         #    dlg.add_filter(filter_any)
 
@@ -331,9 +354,9 @@ def gui_open_file(mime_types=None, start_dir=None):
             return fname
         return None
 
-    @staticmethod
-    # pylint: disable=unused-argument
-    def gui_save_file(mime_types=None, start_dir=None, default_name=None):
+    # pylint: disable=unused-argument, no-self-use
+    def gui_save_file(self, mime_types=None, start_dir=None,
+                      default_name=None):
         '''
         GUI Save File.
 
@@ -376,8 +399,8 @@ def gui_save_file(mime_types=None, start_dir=None, default_name=None):
             return fname
         return None
 
-    @staticmethod
-    def gui_select_dir(start_dir=None):
+    # pylint: disable=no-self-use
+    def gui_select_dir(self, start_dir=None):
         '''
         Gui Select Directory.
 
@@ -405,14 +428,14 @@ def gui_select_dir(start_dir=None):
             return fname
         return None
 
-    @staticmethod
-    def os_version_string():
+    def os_version_string(self):
         '''
         OS Version String.
 
         :returns: "Unknown Operating System"
         :rtype: str
         '''
+        self.logger.info("Unknown Operating System")
         return "Unknown Operating System"
 
     @staticmethod
@@ -487,7 +510,7 @@ def have_sound():
         Do we have sound support?
 
         :returns: Status of sound support
-        :rytpe: bool
+        :rtype: bool
         '''
         return HAVE_AUDIO
 
@@ -502,7 +525,8 @@ def play_sound(self, soundfile):
         if not HAVE_AUDIO:
             self.logger.info("play_sound: "
                              "pydub and pyaudio not installed!")
+            return
 
-        sound = AudioSegment.from_wav(soundfile)
+        sound = AudioSegment.from_wav(soundfile) # type: ignore
         with suppress_stderr():
-            play(sound)
+            play(sound) # type: ignore
diff --git a/d_rats/dplatform_macos.py b/d_rats/dplatform_macos.py
index 641145b6..8b11cbdf 100755
--- a/d_rats/dplatform_macos.py
+++ b/d_rats/dplatform_macos.py
@@ -108,6 +108,8 @@ def sys_data(self):
 
     @staticmethod
     def _unix_doublefork_run(*args):
+        # False positive when editing on some platforms.
+        # pylint: disable=no-member
         pid1 = os.fork()
         if pid1 == 0:
             pid2 = os.fork()
diff --git a/d_rats/dplatform_unix.py b/d_rats/dplatform_unix.py
index 0f0a8d0c..61e84cf2 100755
--- a/d_rats/dplatform_unix.py
+++ b/d_rats/dplatform_unix.py
@@ -57,7 +57,8 @@ def set_config_dir(self, basepath):
             os.makedirs(basepath, exist_ok=True)
         self._base = basepath
 
-    def default_dir(self):
+    @staticmethod
+    def default_dir():
         '''
         Default Directory.
 
@@ -99,11 +100,15 @@ def os_version_string(self):
             issue = open("/etc/issue.net", "r")
             ver = issue.read().strip()
             issue.close()
+            # False positive when editing on some platforms
+            # pylint: disable=no-member
             ver = "%s - %s" % (os.uname()[0], ver)
         except IOError as err:
             if err.errno == 2:  # No such file or directory
                 # Linux use of this file seems to be deprecated.
                 pass
+            # False positive when editing on some platforms
+            # pylint: disable=no-member
             ver = " ".join(os.uname())
         return ver
 
diff --git a/d_rats/dplatform_win32.py b/d_rats/dplatform_win32.py
index a174ea7e..489179a5 100755
--- a/d_rats/dplatform_win32.py
+++ b/d_rats/dplatform_win32.py
@@ -95,7 +95,8 @@ def set_config_dir(self, basepath):
             os.makedirs(basepath, exist_ok=True)
         self._base = basepath
 
-    def default_dir(self):
+    @staticmethod
+    def default_dir():
         '''
         Default Directory.
 
@@ -105,7 +106,8 @@ def default_dir(self):
         return os.path.abspath(
             os.path.join(os.getenv("USERPROFILE"), "Desktop"))
 
-    def filter_filename(self, filename):
+    @staticmethod
+    def filter_filename(filename):
         '''
         Filter Filename.
 
@@ -145,6 +147,8 @@ def list_serial_ports(self):
                     win32file.CloseHandle(port)  # type: ignore
                     port = None
 
+                # On cross platform IDEs pylint may false positive.
+                # pylint: disable=no-member
                 except pywintypes.error as err:  # type: ignore
                     # Error code 5 Apparently if the serial port is in use.
                     # Error code 121 Apparently if timeout in operation.
@@ -196,6 +200,8 @@ def gui_open_file(self, mime_types=None, start_dir=None):
             fname, _filter, __flags = \
                 win32gui.GetOpenFileNameW(Filter=win_filter)  # type: ignore
             return str(fname)
+        # On cross platform IDEs pylint may false positive.
+        # pylint: disable=no-member
         except pywintypes.error as err:  # type: ignore
             self.logger.info("gui_open_file: Failed to get filename: %s", err)
         except NameError:
@@ -221,6 +227,8 @@ def gui_save_file(self, mime_types=None, start_dir=None, default_name=None):
                 win32gui.GetSaveFileNameW(File=default_name,
                                           Filter=win_filter)  # type: ignore
             return str(fname)
+        # On cross platform IDEs pylint may false positive.
+        # pylint: disable=no-member
         except pywintypes.error as err:  # type: ignore
             self.logger.info("gui_save_file: Failed to get filename: %s", err)
         except NameError:
@@ -243,6 +251,8 @@ def gui_select_dir(self, start_dir=None):
                 err = "No error detected"
                 pidl, _display_name, _ilmage_list = \
                     shell.SHBrowseForFolder()  # type: ignore
+            # On cross platform IDEs pylint may false positive.
+            # pylint: disable=no-member
             except pywintypes.com_error:  # type: ignore
                 pass
             if not pidl:
@@ -292,7 +302,7 @@ def have_sound():
         Do we have sound support?
 
         :returns: Status of sound support
-        :rytpe: bool
+        :rtype: bool
         '''
         return HAVE_AUDIO
 
diff --git a/d_rats/utils.py b/d_rats/utils.py
index 5bcb47aa..c0fcd96c 100755
--- a/d_rats/utils.py
+++ b/d_rats/utils.py
@@ -23,10 +23,16 @@
 
 import urllib.request
 
-import gi
-gi.require_version("Gtk", "3.0")
-from gi.repository import Gtk
-from gi.repository import Gdk
+# This version of D-Rats requires GTK 3.0, but not for doing unit
+# tests.   This allows the default unit tests to pass on a system with
+# out GTK+ installed.
+try:
+    import gi
+    gi.require_version("Gtk", "3.0")
+    from gi.repository import Gtk
+    from gi.repository import Gdk
+except (ImportError, ValueError):
+    pass
 
 # This makes pylance happy with out overriding settings
 # from the invoker of the class
diff --git a/tests/pre-commit b/tests/pre-commit
index 366fed41..f28a18b6 100755
--- a/tests/pre-commit
+++ b/tests/pre-commit
@@ -47,9 +47,10 @@ CHANGED_FILES=$(git diff --name-only --cached --diff-filter=ACMR)
 export CHANGED_FILES
 
 rc=0
-for check_script in tests/pre-commit_d/*; do
+for check_script in tests/pre-commit_d/*.sh; do
     if ! "${check_script}"; then
         (( rc=rc+PIPESTATUS[0] ))
+		echo "${check_script} returned $rc"
     fi
 done
 exit "$rc"
diff --git a/tests/pre-commit_d/python_unit_tests.sh b/tests/pre-commit_d/python_unit_tests.sh
new file mode 100755
index 00000000..fa8dee39
--- /dev/null
+++ b/tests/pre-commit_d/python_unit_tests.sh
@@ -0,0 +1,44 @@
+#!/bin/bash
+
+set -uex
+
+# Needed for some platforms
+export NO_AT_BRIDGE=1
+
+# Default list of files to lint
+: "${CHANGED_FILES:=}"
+if [ -z "$CHANGED_FILES" ]; then
+  # Nothing to do
+  exit 0
+fi
+rc=0
+#hack: Only way to put a newline into a variable
+nl='
+'
+delim="$nl"
+
+# If only one file, delimiter does not matter.
+if [[ "$CHANGED_FILES" == *" "* ]]; then
+    delim=" "
+fi
+
+test_scripts=()
+test_scripts+=("d_rats/dplatform")
+test_scripts+=("d_rats/ddt2")
+
+echo "CHANGED_FILES: $CHANGED_FILES"
+for test_script in "${test_scripts[@]}"; do
+    # Hack is to add a leading delimiter for a quick check to
+    # see if filename is in a character delimited path
+    echo "test_script: $test_script"
+    if [[ "$delim$CHANGED_FILES" == *"$delim$test_script"* ]]; then
+        module="${test_scripts//\//.}"
+        python -m "${module}" || rc=1
+    else
+        echo "No script file found."
+        module="${test_scripts//\//.}"
+        echo "module: $module"
+    fi
+done
+echo "final status = ${rc}"
+exit "${rc}"
diff --git a/workflow/Linux/requirements.txt b/workflow/Linux/requirements.txt
new file mode 100755
index 00000000..e8b3f82e
--- /dev/null
+++ b/workflow/Linux/requirements.txt
@@ -0,0 +1,22 @@
+# requirements for d-rats
+# Packages needed for running
+lxml
+Pillow
+# pycairo not available for Ubuntu GitHub workflows
+# PyGObject not available for Ubuntu GitHub workflows
+pyserial
+pycountry
+# packages recommended for running
+geopy
+feedparser
+# pyaudio not available for Ubuntu GitHub workflows
+pydub
+# packages needed for development
+build
+pip
+pylint
+setuptools
+Sphinx
+towncrier
+virtualenv
+wheel
diff --git a/workflow/Windows/requirements.txt b/workflow/Windows/requirements.txt
new file mode 100755
index 00000000..1f2f5e37
--- /dev/null
+++ b/workflow/Windows/requirements.txt
@@ -0,0 +1,24 @@
+# requirements for d-rats
+# Microsoft Windows needed
+pywin32
+# Packages needed for running
+lxml
+Pillow
+pycairo
+# PyGObject not available for Windows GitHub workflows
+pyserial
+pycountry
+# packages recommended for running
+geopy
+feedparser
+pyaudio
+pydub
+# packages needed for development
+build
+pip
+pylint
+setuptools
+Sphinx
+towncrier
+virtualenv
+wheel
diff --git a/workflow/macOS/requirements.txt b/workflow/macOS/requirements.txt
new file mode 100755
index 00000000..da814695
--- /dev/null
+++ b/workflow/macOS/requirements.txt
@@ -0,0 +1,22 @@
+# requirements for d-rats
+# Packages needed for running
+lxml
+Pillow
+pycairo
+PyGObject
+pyserial
+pycountry
+# packages recommended for running
+geopy
+feedparser
+# pyaudio not available on macos in GitHub Workflows.
+pydub
+# packages needed for development
+build
+pip
+pylint
+setuptools
+Sphinx
+towncrier
+virtualenv
+wheel