putting current class as return type annotation [duplicate]

by

In python-3.7 this issue has been resolved by not evaluating the annotations at function definition time. Instead, they are preserved in __annotations__ in string form. This is called Postponed Evaluation of Annotations, introduced in PEP 563.

Also note:

Deprecation policy

Starting with Python 3.7, a __future__ import is required to use the
described functionality. No warnings are raised.

In Python 3.8 a PendingDeprecationWarning is raised by the compiler in
the presence of type annotations in modules without the __future__
import.

Starting with Python 3.9 the warning becomes a DeprecationWarning.

In Python 4.0 this will become the default behavior. Use of
annotations incompatible with this PEP is no longer supported.

Here is an example:

In [7]: from __future__ import annotations

In [8]: class C:
   ...:     def func(cls, arg:str) -> C:
   ...:         pass
   ...:     

In [9]: c = C()

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