update envs for better XDG base directory support

home/private_dot_config/python/pythonrc

@@ -0,0 +1,37 @@
+#!/usr/bin/env python3
+# This entire thing is unnecessary post v3.13.0a3
+# https://github.com/python/cpython/issues/73965
+
+def is_vanilla() -> bool:
+    """ :return: whether running "vanilla" Python """
+    import sys
+    return not hasattr(__builtins__, '__IPYTHON__') and 'bpython' not in sys.argv[0]
+
+
+def setup_history():
+    """ read and write history from state file """
+    import os
+    import atexit
+    import readline
+    from pathlib import Path
+
+    # https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html#variables
+    if state_home := os.environ.get('XDG_STATE_HOME'):
+            state_home = Path(state_home)
+    else:
+        state_home = Path.home() / '.local' / 'state'
+    if not state_home.is_dir():
+        print("Error: XDG_STATE_HOME does not exist at", state_home)
+
+    history: Path = state_home / 'python_history'
+
+    # https://github.com/python/cpython/issues/105694
+    if not history.is_file():
+        readline.write_history_file(str(history)) # breaks on macos + python3 without this.
+
+    readline.read_history_file(history)
+    atexit.register(readline.write_history_file, history)
+
+
+if is_vanilla():
+    setup_history()