#122 PxXB should allow to assign `None` to optional elements and attributes

[Dieter Maurer]

Optional attributes return None on access to indicate that the attribute is missing. However, when one tries to assign None to an optional attribute, this can result in:

  Module pyxb.binding.basis, line 62, in __setattr__
  Module pyxb.binding.content, line 410, in set
AssertionError

This can make assigning attributes quite complicated, especially if one creates one binding object from another one. Instead of "dest.attr = "src.attr" one must use code "if src.attr is not None: dest.attr = src.attr".

[Peter A. Bigot]

• status changed from new to closed
• resolution set to fixed

commit bbeea8f212a3e3b9a5c42cd2171970e3e20fc113
Author: Peter A. Bigot <pabigot@…>
Date: Sat Feb 25 10:02:56 2012 -0600

trac/122: PxXB should allow to assign None to optional elements and attributes

Support assignment of None to non-required attributes. For completeness,
also allow this for Prohibited attributes, though if the property-based
access method is used this would be prevented by a different mechanism.