[3.13] gh-95844: Move help_url code to a help module function (GH-129971) (#138485)

gh-95844: Move help_url code to a help module function (GH-129971)

---------
(cherry picked from commit 3b4cd88563)

Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>
Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>

Lib/idlelib/editor.py

@@ -29,6 +29,7 @@ from idlelib import search
 from idlelib.tree import wheel_event
 from idlelib.util import py_extensions
 from idlelib import window
+from idlelib.help import _get_dochome
 
 # The default tab setting for a Text widget, in average-width characters.
 TK_TABWIDTH_DEFAULT = 8
@@ -76,44 +77,7 @@ class EditorWindow:
         from idlelib.runscript import ScriptBinding
 
         if EditorWindow.help_url is None:
-            dochome =  os.path.join(sys.base_prefix, 'Doc', 'index.html')
-            if sys.platform.count('linux'):
-                # look for html docs in a couple of standard places
-                pyver = 'python-docs-' + '%s.%s.%s' % sys.version_info[:3]
-                if os.path.isdir('/var/www/html/python/'):  # "python2" rpm
-                    dochome = '/var/www/html/python/index.html'
-                else:
-                    basepath = '/usr/share/doc/'  # standard location
-                    dochome = os.path.join(basepath, pyver,
-                                           'Doc', 'index.html')
-            elif sys.platform[:3] == 'win':
-                import winreg  # Windows only, block only executed once.
-                docfile = ''
-                KEY = (rf"Software\Python\PythonCore\{sys.winver}"
-                        r"\Help\Main Python Documentation")
-                try:
-                    docfile = winreg.QueryValue(winreg.HKEY_CURRENT_USER, KEY)
-                except FileNotFoundError:
-                    try:
-                        docfile = winreg.QueryValue(winreg.HKEY_LOCAL_MACHINE,
-                                                    KEY)
-                    except FileNotFoundError:
-                        pass
-                if os.path.isfile(docfile):
-                    dochome = docfile
-            elif sys.platform == 'darwin':
-                # documentation may be stored inside a python framework
-                dochome = os.path.join(sys.base_prefix,
-                        'Resources/English.lproj/Documentation/index.html')
-            dochome = os.path.normpath(dochome)
-            if os.path.isfile(dochome):
-                EditorWindow.help_url = dochome
-                if sys.platform == 'darwin':
-                    # Safari requires real file:-URLs
-                    EditorWindow.help_url = 'file://' + EditorWindow.help_url
-            else:
-                EditorWindow.help_url = ("https://docs.python.org/%d.%d/"
-                                         % sys.version_info[:2])
+            EditorWindow.help_url = _get_dochome()
         self.flist = flist
         root = root or flist.root
         self.root = root

Lib/idlelib/help.py

@@ -23,7 +23,12 @@ HelpWindow - Display HelpFrame in a standalone window.
 copy_strip - Copy the text part of idle.html to help.html while rstripping each line.
 
 show_idlehelp - Create HelpWindow.  Called in EditorWindow.help_dialog.
+
+_get_dochome() - Return path to docs on user's system if present,
+otherwise return link to docs.python.org.
 """
+import os
+import sys
 from html.parser import HTMLParser
 from os.path import abspath, dirname, isfile, join
 from platform import python_version
@@ -289,6 +294,47 @@ def show_idlehelp(parent):
     return HelpWindow(parent, filename, 'IDLE Doc (%s)' % python_version())
 
 
+def _get_dochome():
+    "Return path to local docs if present, otherwise link to docs.python.org."
+
+    dochome = os.path.join(sys.base_prefix, 'Doc', 'index.html')
+    if sys.platform.count('linux'):
+        # look for html docs in a couple of standard places
+        pyver = 'python-docs-' + '%s.%s.%s' % sys.version_info[:3]
+        if os.path.isdir('/var/www/html/python/'):  # rpm package manager
+            dochome = '/var/www/html/python/index.html'
+        else:
+            basepath = '/usr/share/doc/'  # dnf/apt package managers
+            dochome = os.path.join(basepath, pyver, 'Doc', 'index.html')
+
+    elif sys.platform[:3] == 'win':
+        import winreg  # Windows only, block only executed once.
+        docfile = ''
+        KEY = (rf"Software\Python\PythonCore\{sys.winver}"
+               r"\Help\Main Python Documentation")
+        try:
+            docfile = winreg.QueryValue(winreg.HKEY_CURRENT_USER, KEY)
+        except FileNotFoundError:
+            try:
+                docfile = winreg.QueryValue(winreg.HKEY_LOCAL_MACHINE, KEY)
+            except FileNotFoundError:
+                pass
+        if os.path.isfile(docfile):
+            dochome = docfile
+    elif sys.platform == 'darwin':
+        # documentation may be stored inside a python framework
+        dochome = os.path.join(sys.base_prefix,
+                               'Resources/English.lproj/Documentation/index.html')
+    dochome = os.path.normpath(dochome)
+    if os.path.isfile(dochome):
+        if sys.platform == 'darwin':
+            # Safari requires real file:-URLs
+            return 'file://' + dochome
+        return dochome
+    else:
+        return "https://docs.python.org/%d.%d/" % sys.version_info[:2]
+
+
 if __name__ == '__main__':
     from unittest import main
     main('idlelib.idle_test.test_help', verbosity=2, exit=False)