[QGIS-Developer] For an enum in pyqgis, how do I list all members and do reverse lookups?

[Thomas Larsen Wessel]

Thanks. And that function works well for e.g.
qgis.qgis.PyQt.Qt.QCborSimpleType. Which by the way has type enum.EnumType,
and is defined in QGIS/share/qgis/python/qgis/PyQt/Qt.py.

But Im talking about an "enum" created by SIP. Such an "enum" is a class
definition, with 'int' as its only parent class. It has around 14
enum-members, e.g. "Symbology". But there is no way of getting a complete
list of them. Neither with __dict__ nor dir.

>>> from qgis.core import QgsMapLayer
>>> QgsMapLayer.StyleCategory
<class 'qgis._core.QgsMapLayer.StyleCategory'>
>>> type(QgsMapLayer.StyleCategory)
<class 'sip.enumtype'>
>>> QgsMapLayer.StyleCategory.__dict__
mappingproxy({'__module__': 'qgis._core', '__or__': <slot wrapper '__or__'
of 'StyleCategory' objects>, '__ror__': <slot wrapper '__ror__' of
'StyleCategory' objects>, '__dict__': <attribute '__dict__' of
'StyleCategory' objects>, '__doc__': None, '__reduce__': <method
'_pickle_enum' of 'StyleCategory' objects>, 'baseClass': <class
'qgis._core.QgsMapLayer'>})
>>> dir(QgsMapLayer.StyleCategory)
['__abs__', '__add__', '__and__', '__bool__', '__ceil__', '__class__',
'__delattr__', '__dict__', '__dir__', '__divmod__', '__doc__', '__eq__',
'__float__', '__floor__', '__floordiv__', '__format__', '__ge__',
'__getattribute__', '__getnewargs__', '__getstate__', '__gt__', '__hash__',
'__index__', '__init__', '__init_subclass__', '__int__', '__invert__',
'__le__', '__lshift__', '__lt__', '__mod__', '__module__', '__mul__',
'__ne__', '__neg__', '__new__', '__or__', '__pos__', '__pow__', '__radd__',
'__rand__', '__rdivmod__', '__reduce__', '__reduce_ex__', '__repr__',
'__rfloordiv__', '__rlshift__', '__rmod__', '__rmul__', '__ror__',
'__round__', '__rpow__', '__rrshift__', '__rshift__', '__rsub__',
'__rtruediv__', '__rxor__', '__setattr__', '__sizeof__', '__str__',
'__sub__', '__subclasshook__', '__truediv__', '__trunc__', '__xor__',
'as_integer_ratio', 'baseClass', 'bit_count', 'bit_length', 'conjugate',
'denominator', 'from_bytes', 'imag', 'is_integer', 'numerator', 'real',
'to_bytes']
>>> QgsMapLayer.StyleCategory.Symbology # but the members are there !
2


On Wed, Jul 2, 2025 at 10:00 AM Julien Cabieces <
julien.cabieces at oslandia.com> wrote:

>
> Hi,
>
> If you want an example, it has been done here:
>
> https://github.com/qgis/QGIS/blob/cb48529abf5bd81e3c97d09809e3d56e51c943bd/scripts/pyqt5_to_pyqt6/pyqt5_to_pyqt6.py#L796
>
> You have to use __dict__. But I'm not sure this is a good thing to use
> this in a plugin. The script I mention is an helper for migration from
> qt5 to qt6, so it's kind of special.
>
> Regards,
> Julien
>
>
>
> > Happy summer to all of you :)
> >
> > It seems in the Python bindings produced by SIP, a C++ enum is just a
> Python class with a certain structure. And with little/none possibility of
> > introspection.
> >
> > But how can I get a list with all enum-members (e.g. Symbology, Fields)
> of that enum?
> >
> > dir(QgsMapLayer.StyleCategory) does not list them, and
> QgsMapLayer.StyleCategory.__members__ is undefined.
> >
> > Do I really have to hard code the member names into my plugin, if I want
> to iterate over all of them?
> >
> > Sincerely, Thomas
> >
> > _______________________________________________
> > QGIS-Developer mailing list
> > QGIS-Developer at lists.osgeo.org
> > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer
> > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
>
> --
>
> Julien Cabieces
> Senior Developer at Oslandia
> julien.cabieces at oslandia.com
>
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