Add type hints to ann, meta

[janga1997]

#808
In ann.py, I am not really sure what the type of weights is supposed to be. I think it should be a list, but it could also be an numpy array? Any other iterable?
In meta.py , What is team's type supposed to be?
I am not sure, but I think these are the last of the strategies to add type hints to.

[marcharper]

weights is a list of floats. A numpy array might work but I don't think we ever use it as such.

team is a list of player classes I think.

[drvinceknight]

I'm not too sure why travis has not run on this: it's only showing 1 successful check (on Appveyor)...

[drvinceknight]

I've run mypy locally and get:

Axelrod(janga1997-typeHint11): python run_mypy.py 
axelrod/strategies/ann.py:191: error: Argument 4 to "activate" has incompatible type List[int]; expected List[float]
axelrod/strategies/ann.py:195: error: Unsupported operand types for < ("int" and List[float])
axelrod/strategies/meta.py:94: error: Signature of "meta_strategy" incompatible with supertype "MetaPlayer"
axelrod/strategies/meta.py:109: error: Signature of "meta_strategy" incompatible with supertype "MetaPlayer"
axelrod/strategies/meta.py:211: error: Signature of "meta_strategy" incompatible with supertype "MetaPlayer"
axelrod/strategies/meta.py:249: error: Signature of "meta_strategy" incompatible with supertype "MetaPlayer"
axelrod/strategies/meta.py:390: error: Invalid type "axelrod.strategies.meta.NiceMetaWinnerEnsemble"
axelrod/strategies/meta.py:390: error: Invalid base class
axelrod/strategies/meta.py:402: error: Invalid type "axelrod.strategies.meta.NiceMetaWinnerEnsemble"
axelrod/strategies/meta.py:402: error: Invalid base class
axelrod/strategies/meta.py:413: error: Invalid type "axelrod.strategies.meta.NiceMetaWinnerEnsemble"
axelrod/strategies/meta.py:413: error: Invalid base class
axelrod/strategies/meta.py:424: error: Invalid type "axelrod.strategies.meta.NiceMetaWinnerEnsemble"
axelrod/strategies/meta.py:424: error: Invalid base class
axelrod/strategies/meta.py:435: error: Invalid type "axelrod.strategies.meta.NiceMetaWinnerEnsemble"
axelrod/strategies/meta.py:435: error: Invalid base class

This could be due to an updated version of mypy so try pip install -U mypy.

[janga1997]

@drvinceknight The Signature errors have something to do with the @staticmethod decorator, although I don't know what.
And NiceTransformer imported from strategy_transformer.py,and used to define NiceMetaWinnerEnsemble is raising the errors.

[drvinceknight]

@drvinceknight The Signature errors have something to do with the @staticmethod decorator, although I don't know what.
And NiceTransformer imported from strategy_transformer.py,and used to define NiceMetaWinnerEnsemble is raising the errors.

I've taken a brief look @janga1997 but I'm afraid I don't see what the right way to do it is here... I can try and take another look during the week at some point if you don't find a way to do it.

[marcharper]

The staticmethod related error is literally saying that type signature of the child class meta_strategy method is different than the parent class, which is technically correct. It's just not clear why that is an error.

The second issue is a bit more subtle. The decorated classes are created at runtime so the type checker thinks that the base strategy type either doesn't exist or is invalid. This may be a limitation of mypy, and there may be a workaround where we declare these players to be instances or child classes of MetaPlayer.

[marcharper]

@janga1997 Do you want break out the ann and apavlov changes so we can merge those while we sort the metaplayer issues?

[janga1997]

@marcharper I've not been able to find the time recently.
I removed the commit for the meta.py file.

[drvinceknight]

We've had some failures back:

59.35s$ python run_mypy.py
axelrod/strategies/meta.py:389: error: Invalid type "axelrod.strategies.meta.NiceMetaWinnerEnsemble"
axelrod/strategies/meta.py:389: error: Invalid base class
axelrod/strategies/meta.py:401: error: Invalid type "axelrod.strategies.meta.NiceMetaWinnerEnsemble"
axelrod/strategies/meta.py:401: error: Invalid base class
axelrod/strategies/meta.py:412: error: Invalid type "axelrod.strategies.meta.NiceMetaWinnerEnsemble"
axelrod/strategies/meta.py:412: error: Invalid base class
axelrod/strategies/meta.py:423: error: Invalid type "axelrod.strategies.meta.NiceMetaWinnerEnsemble"
axelrod/strategies/meta.py:423: error: Invalid base class
axelrod/strategies/meta.py:434: error: Invalid type "axelrod.strategies.meta.NiceMetaWinnerEnsemble"
axelrod/strategies/meta.py:434: error: Invalid base class

[janga1997]

@drvinceknight I forgot to remove meta.py from run_mypy

[drvinceknight]

@drvinceknight I forgot to remove meta.py from run_mypy

Great! Travis is happy (and both ann.py and apavlov.py are being run through mypy: https://github.com/Axelrod-Python/Axelrod/blob/master/run_mypy.py#L14)