ychennay

# both classes below implement Python properties using data descriptors
class StudentWithInlineProps:
    def __init__(self, name="Default Name"):
        self._name = name

    # getting the values
    def get_name(self):
        print('Getting value')
        return self._name

ychennay

class ForeignKeyDeferredAttribute(DeferredAttribute):
    def __set__(self, instance, value):
        if instance.__dict__.get(self.field.attname) != value and self.field.is_cached(instance):
            self.field.delete_cached_value(instance)
        instance.__dict__[self.field.attname] = value

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class NonNullStringDescriptor:

    def __init__(self, value: str = "Default Name"):
        self.value = value

    def __get__(self, instance, owner):
        print(f"__get__({self}, {instance}, {owner})")
        return self.value

    def __set__(self, instance, value):

ychennay

    f = NULL;
    if (descr != NULL) {
        Py_INCREF(descr); // increase the reference count of the descriptor
        f = descr->ob_type->tp_descr_get; // access the descriptor's getter method from the descriptor's PyTypeObject ob_type
        if (f != NULL && PyDescr_IsData(descr)) {
            res = f(descr, obj, (PyObject *)obj->ob_type); // actual call to the descriptor's __get__
            if (res == NULL && suppress &&
                    PyErr_ExceptionMatches(PyExc_AttributeError)) {
                PyErr_Clear();
            }

ychennay

class Person:

    def __init__(self, name):
        self.__secret_attribute = 42
        self.name = name


if __name__ == "__main__":
    person = Person("Yu")
    # print(person.__secret_attribute) # AttributeError: 'Person' object has no attribute '__secret_attribute'

ychennay

package com.yuchen;

public class Student {

    public String name;
    public float gpa;
    
    public String getName() {
        return name;
    }

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    # Add fields from abstract base class if it wasn't overridden.
    for field in parent_fields:
        if (field.name not in field_names and
                field.name not in new_class.__dict__ and
                field.name not in inherited_attributes):
            new_field = copy.deepcopy(field)
            new_class.add_to_class(field.name, new_field)
            # Replace parent links defined on this base by the new
            # field. It will be appropriately resolved if required.
            if field.one_to_one:

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  # Basic setup for proxy models.
  if is_proxy:
      base = None
      for parent in [kls for kls in parents if hasattr(kls, '_meta')]:
          if parent._meta.abstract:
              if parent._meta.fields:
                  raise TypeError(
                      "Abstract base class containing model fields not "
                      "permitted for proxy model '%s'." % name
                  )

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class Student(models.Model):
   ...
   
class SpecificStudent(Student):
    class Meta:
        proxy = True

    def perform_student_specific_action(self):
        # ...
        pass

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      # Inherit private fields (like GenericForeignKey) from the parent
      # class
      for field in base._meta.private_fields:
          if field.name in field_names:
              if not base._meta.abstract:
                  raise FieldError(
                      'Local field %r in class %r clashes with field of '
                      'the same name from base class %r.' % (
                          field.name,
                          name,