Note: This is the closest you're going to get to a PEP from me! Okay, i have found a solution to the type hinting problem that will appease both sides. On one side we have those who are proposing type hinting annotations within function sigs, and on the other side, we have those who oppose the implementation of type hinting via this method because of the readability concerns. The solution is move the type hinting syntax completely out of the source file and into another file -- think of it as a "Python Type Hinting Header File".
============================================================ Summary ============================================================ (1) Agree on a file extension that python will recognize as containing "type hint specs". Unfortunately we cannot use ".pth", which would be the perfect acronym for "Python Type Hints", so choose something else. :-( (2) Define a spec for writing annotations that will map to funcs/methods of the same name. I would argue to keep the spec compact, but i really don't care about the spec at this point. ============================================================ Simplistic Example Code utilizing two files: ============================================================ # # scriptA.py # def greeting(name): return 'Hello ' + name # # scriptA.typehints # greeting{name:str} -> str ============================================================ Benefits: ============================================================ (1) Removes the noisy syntax from the source file. Python code will remain as clean tomorrow as it is today. (2) Puts the onerous on the author *NOT* on the reader. This system utilizes a concept known as "Level Of Detail" (or LOD). LOD means that i should not need to see a type hint unless i *WANT* to see a type hint. You can think of it as akin to "Java @string resources". (3) If i decide i don't want type hints in my code, all i have to do is delete or rename a file, which is much less error prone then editing source code. (4) Has the added benefit of aiding when debugging type hints. -- My suggestion is the only way to implement type hints without destroying Python! I just hope that GvR will give it serious objective consideration. -- https://mail.python.org/mailman/listinfo/python-list