[eryntools] A new Python module full of useful utilities

Add a scripting module that implements absolute_script_path().

Python/eryntools/src/eryntools/__init__.py

@@ -0,0 +1,2 @@
+#!/usr/local/env python3
+# Eryn Wells <eryn@erynwells.me>

Python/eryntools/src/eryntools/scripting.py

@@ -0,0 +1,11 @@
+# Eryn Wells <eryn@erynwells.me>
+
+import os.path
+import sys
+from typing import Optional
+
+
+def absolute_script_path(argv0: Optional[str] = None) -> Optional[str]:
+    '''Get the absolute path to the currently executing script.'''
+    executable = argv0 or sys.argv[0]
+    return os.path.abspath(executable) if executable else None