Lib: Improve IDLE launcher script for clarity and safety

Author: TheAhumMaitra

Doc/tutorial/introduction.rst

@@ -63,8 +63,6 @@ For example::
    5.0
    >>> 8 / 5  # division always returns a floating-point number
    1.6
-   >>> 2 ** 9 #2 raised to the power of 9
-   512
 
 The integer numbers (e.g. ``2``, ``4``, ``20``) have type :class:`int`,
 the ones with a fractional part (e.g. ``5.0``, ``1.6``) have type

Lib/idlelib/idle.py

@@ -1,14 +1,27 @@
-import os.path
+import os
 import sys
 
+def add_idlelib_to_path():
+    """
+    Adds the parent directory of the current file's parent directory
+    to sys.path to allow running IDLE from a non-standard location.
+    """
+    idlelib_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), ".."))
+    if idlelib_dir not in sys.path:
+        sys.path.insert(0, idlelib_dir)
+    return idlelib_dir
 
-# Enable running IDLE with idlelib in a non-standard location.
-# This was once used to run development versions of IDLE.
-# Because PEP 434 declared idle.py a public interface,
-# removal should require deprecation.
-idlelib_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
-if idlelib_dir not in sys.path:
-    sys.path.insert(0, idlelib_dir)
+def main():
+    """
+    Import and run IDLE's main shell.
+    """
+    add_idlelib_to_path()
+    try:
+        from idlelib.pyshell import main as idle_main
+    except ImportError as e:
+        print("Could not import idlelib.pyshell:", e)
+        sys.exit(1)
+    idle_main()
 
-from idlelib.pyshell import main  # This is subject to change
-main()
+if __name__ == "__main__":
+    main()

README.rst

@@ -232,4 +232,4 @@ This Python distribution contains *no* GNU General Public License (GPL) code,
 so it may be used in proprietary projects.  There are interfaces to some GNU
 code but these are entirely optional.
 
-All trademarks referenced herein are property of their respective holders.
+All trademarks referenced herein are property of their respective holders.

iOS/testbed/__main__.py

@@ -99,6 +99,7 @@ def clone_testbed(
         print(f"{target} already exists; aborting without creating project.")
         sys.exit(10)
 
+
     if framework is None:
         if not (
             source / "Python.xcframework/ios-arm64_x86_64-simulator/bin"