AttributeError: 'module' object has no attribute 'SubfieldBase'

[ahmed dawod]

I'm working on a project that was built using an earlier version of django. My environment has the latest Django version (1.11.4). 

When I try to "python manage.py runserver" I get this: 

Unhandled exception in thread started by <function wrapper at 0x7fb1dab36cf8>

Traceback (most recent call last):

  File "/usr/local/lib/python2.7/dist-packages/django/utils/autoreload.py", line 228, in wrapper

    fn(*args, **kwargs)

  File "/usr/local/lib/python2.7/dist-packages/django/core/management/commands/runserver.py", line 117, in inner_run

    autoreload.raise_last_exception()

  File "/usr/local/lib/python2.7/dist-packages/django/utils/autoreload.py", line 251, in raise_last_exception

    six.reraise(*_exception)

  File "/usr/local/lib/python2.7/dist-packages/django/utils/autoreload.py", line 228, in wrapper

    fn(*args, **kwargs)

  File "/usr/local/lib/python2.7/dist-packages/django/__init__.py", line 27, in setup

    apps.populate(settings.INSTALLED_APPS)

  File "/usr/local/lib/python2.7/dist-packages/django/apps/registry.py", line 108, in populate

    app_config.import_models()

  File "/usr/local/lib/python2.7/dist-packages/django/apps/config.py", line 202, in import_models

    self.models_module = import_module(models_module_name)

  File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module

    __import__(name)

  File "/home/ahmedn1/Documents/Paymob/wallet_executive_panel-master-c109bd6fe9cd1bf793c11a5c2e97d18a1887c3ba/accounts/models.py", line 8, in <module>

    import timedelta

  File "/usr/local/lib/python2.7/dist-packages/timedelta/__init__.py", line 11, in <module>

    from .fields import TimedeltaField

  File "/usr/local/lib/python2.7/dist-packages/timedelta/fields.py", line 18, in <module>

    class TimedeltaField(six.with_metaclass(models.SubfieldBase, models.Field)):

AttributeError: 'module' object has no attribute 'SubfieldBase'

So the problem is with the django-timedeltafield package but its version is 0.7.10 which is the latest version. So, why does it still have a problem with this deprecated SubfieldBase? 

What should I do to solve the problem?  

[Tim Graham]

From https://bitbucket.org/schinckel/django-timedelta-field: "If you are using Django 1.8 or greater (and you really _should_ be), then you should use the included DurationField() instead of this. This field does not work with Django 1.10, and will probably not be updated to fix the issue(s). When migrating TimedeltaField to DurationField using Django migrations, alter any migrations that have an import to this library to mention the new field type, this works to prevent Django from crashing when trying to run the deprecated code."