Things That Work
- Class constants corresponding to string enumeration constraints
- Simple and complex type definitions
- List and union datatypes
- Constraints on (simple) datatypes (e.g., minInclusive, length)
- Model groups and attribute groups
- Complex content models (all, sequence, choice); minOccurs and maxOccurs
- Abstract types, xsi:type,
- Nillable elements with xsi:nil
- Namespace qualified attributes and elements
- Documentation annotations present in the schema are converted to Python
docstrings in the generated bindings.
- Pattern constraints (as long as the simple type derives from something
that is represented as a Python string)
Things That Don’t Work
...but could someday
- Identity constraints (“key”, “unique”, “keyref”) are stored in the content
model, but are not used.
- Wildcard elements are
supported in the sense that classes that enable them in the content model
provide access to unrecognized values through the
Where the type of the node is recognized, it is converted to a Python
binding instance; otherwise, the xml DOM instance is stored. Although
namespace constraints are applied when checking for wildcard matches, the
process contents attribute of the wildcard is ignored.
- Wildcard attributes are supported
in much the same sense as wildcard elements: no constraints are checked,
and all are aggregated into the
Values are uninterpreted Unicode strings.
...and probably never will
- The redefine directive
is not supported.
- The ability to use templates to customize binding generation was promised
in the vision document, but after three years of no plausible use case it
is no longer part of the plan.
Things That Mostly Work, But They’re Ugly
- The duration type is based
on the Python
datetime.timedelta class, which works reasonably well
for small deltas but does not handle month and year deltas. The PyXB
version records that information, but the
datetime instances) does not incorporate
that portion of the delta. Negative durations also may not work properly.