Fix re import on Pythonic as well

Add some notes to remind maintainers to update both files.

inst/private/python_header.py

@@ -8,6 +8,9 @@
 
 # In some cases this code is fed into stdin: two blank lines between
 # try-except blocks, no blank lines within each block.
+#
+# Maintenance note: this code is largely duplicated with python_ipc_native
+# Ensure both are updated!
 
 import sys
 

inst/private/python_ipc_native.m

@@ -1,4 +1,4 @@
-%% Copyright (C) 2016, 2018-2019, 2023 Colin B. Macdonald
+%% Copyright (C) 2016, 2018-2019, 2023-2024 Colin B. Macdonald
 %% Copyright (C) 2016 Abhinav Tripathi
 %% Copyright (C) 2021 Johannes Maria Frank
 %% Copyright (C) 2022 Chris Gorman
@@ -61,11 +61,13 @@
   newl = sprintf('\n');
 
   if isempty(have_headers)
+    % Maintenance note: you must edit both this and python_header.py
     pyexec(strjoin({'import sys'
                     'import sympy'
                     'import mpmath'
                     'import sympy as sp'
                     'from sympy import __version__ as spver'
+                    'from re import split as lib_re_split'
                     'from sympy import *'
                     'from sympy.logic.boolalg import Boolean, BooleanFunction'
                     'from sympy.core.relational import Relational'
@@ -97,7 +99,6 @@
                     '            return LooseVersion(v.replace(".dev", ""))'
                     'import itertools'
                     'import collections'
-                    'from re import split'
                     '# patch pretty printer, issue #952'
                     'from sympy.printing.pretty.pretty import PrettyPrinter'
                     '_mypp = PrettyPrinter'