      default_error_messages = {
          'invalid': _('Not a valid string.'),
          'blank': _('This field may not be blank.'),
          'max_length': _('Ensure this field has no more than {max_length} characters.'),
          'min_length': _('Ensure this field has at least {min_length} characters.')
      }
      initial = ''
  
      def __init__(self, **kwargs):
          self.allow_blank = kwargs.pop('allow_blank', False)
 
</s> remove     MinValueValidator, unicode_repr, unicode_to_repr
 </s> add     MinValueValidator, ProhibitNullCharactersValidator, unicode_repr,
    unicode_to_repr
        'min_length': _('Ensure this field has at least {min_length} characters.'),
      default_error_messages = {
          'invalid': _('Not a valid string.'),
          'blank': _('This field may not be blank.'),
          'max_length': _('Ensure this field has no more than {max_length} characters.'),
        'min_length': _('Ensure this field has at least {min_length} characters.'),
      }
      initial = ''
  
      def __init__(self, **kwargs):
          self.allow_blank = kwargs.pop('allow_blank', False)
keep keep keep keep replace keep keep keep keep keep
 Prohibit null characters in CharField by default (#6073)

* Implement an allow_null_bytes argument to CharField (default True)
* Switch to using native ProhibitNullCharactersValidator instead 
rest_framework/fields.py