Add setup_helper.py with duplicate_package_info

docs/index.rst

@@ -9,6 +9,27 @@ Ska Package Helpers
 .. automodule:: ska_helpers
    :members:
 
+Logging
+-------
+
+.. automodule:: ska_helpers.logging
+   :members:
+
+
+Retry
+-----
+
+.. automodule:: ska_helpers.retry
+   :members:
+
+
+Setup Helpers
+-------------
+
+.. automodule:: ska_helpers.setup_helper
+   :members:
+
+
 Utilities
 ---------
 

ska_helpers/setup_helper.py

@@ -0,0 +1,23 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
+
+def duplicate_package_info(vals, name_in, name_out):
+    """
+    Duplicate a list or dict of values inplace, replacing ``name_in`` with ``name_out``.
+
+    Normally used in setup.py for making a namespace package that copies a flat one.
+    For an example see setup.py in the ska_sun or Ska.Sun repo.
+
+    :param vals: list or dict of values
+    :param name_in: string to replace at start of each value
+    :param name_out: output string
+    """
+    import re
+
+    for name in list(vals):
+        new_name = re.sub(f"^{name_in}", name_out, name)
+        if isinstance(vals, dict):
+            vals[new_name] = vals[name]
+        else:
+            vals.append(new_name)
+
+