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Get All Subclasses of a Python Class and Get Concrete Django Models
def get_all_subclasses(python_class):
"""
Helper function to get all the subclasses of a class.
:param python_class: Any Python class that implements __subclasses__()
"""
python_class.__subclasses__()
subclasses = set()
check_these = [python_class]
while check_these:
parent = check_these.pop()
for child in parent.__subclasses__():
if child not in subclasses:
subclasses.add(child)
check_these.append(child)
return sorted(subclasses, key=lambda x: x.__name__)
def get_concrete_models(base_model):
"""
Helper function to get all concrete models
that are subclasses of base_model
in sorted order by name.
:param base_model: A Django models.Model instance.
"""
found = get_all_subclasses(base_model)
def filter_func(model):
meta = getattr(model, '_meta', '')
if getattr(meta, 'abstract', True):
# Skip meta classes
return False
if '_Deferred_' in model.__name__:
# See deferred_class_factory() in django.db.models.query_utils
# Catches when you do .only('attr') on a queryset
return False
return True
subclasses = list(filter(filter_func, found))
return sorted(subclasses, key=lambda x: x.__name__)
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