Actually there is, at least for pycharm. I actually opened a jira on it 
(https://issues.apache.org/jira/browse/SPARK-17333). It describes two way of 
doing it (I also made a github stub at: 
https://github.com/assafmendelson/ExamplePysparkAnnotation). Unfortunately, I 
never found the time to follow through.
That said, If we make a decision on the way to handle it then I believe it 
would be a good idea to start even with the bare minimum and continue to add to 
it (and therefore make it so many people can contribute). The code I added in 
github were basically the things I needed.

To summarize, there are two main ways of doing it (at least in pycharm):

1.       Give the hints as part of the docstring for the function

2.       Create files with the signatures only and mark it for pycharm to use

The advantage of the first is that it is part of the code which means it is 
easier to make it updated. The main issue with this is that supporting auto 
generated code (as is the case in most functions) can be a little awkward and 
actually is a relate to a separate issue as it means pycharm marks most of the 
functions as an error (i.e. pyspark.sql.functions.XXX is marked as not there…)

The advantage of the second is that it is completely separate so messing around 
with it cannot harm the main code. The disadvantages are that we would need to 
maintain it manually and that to use it in pycharm, one needs to add them to 
the path (in pycharm this means mark them as source, I am not sure how other 
IDEs support this).

Lastly, I only tested these two solutions for pycharm. I am not sure of their 
support in other IDEs.


Thanks,
              Assaf.

From: rxin [via Apache Spark Developers List] 
[mailto:ml+s1001551n21611...@n3.nabble.com]
Sent: Tuesday, May 23, 2017 1:10 PM
To: Mendelson, Assaf
Subject: Re: [PYTHON] PySpark typing hints

Seems useful to do. Is there a way to do this so it doesn't break Python 2.x?


On Sun, May 14, 2017 at 11:44 PM, Maciej Szymkiewicz <[hidden 
email]</user/SendEmail.jtp?type=node&node=21611&i=0>> wrote:

Hi everyone,

For the last few months I've been working on static type annotations for 
PySpark. For those of you, who are not familiar with the idea, typing hints 
have been introduced by PEP 484 (https://www.python.org/dev/peps/pep-0484/) and 
further extended with PEP 526 (https://www.python.org/dev/peps/pep-0526/) with 
the main goal of providing information required for static analysis. Right now 
there a few tools which support typing hints, including Mypy 
(https://github.com/python/mypy) and PyCharm 
(https://www.jetbrains.com/help/pycharm/2017.1/type-hinting-in-pycharm.html).  
Type hints can be added using function annotations 
(https://www.python.org/dev/peps/pep-3107/, Python 3 only), docstrings, or 
source independent stub files 
(https://www.python.org/dev/peps/pep-0484/#stub-files). Typing is optional, 
gradual and has no runtime impact.

At this moment I've annotated majority of the API, including majority of 
pyspark.sql and pyspark.ml<http://pyspark.ml>. At this moment project is still 
rough around the edges, and may result in both false positive and false 
negatives, but I think it become mature enough to be useful in practice.
The current version is compatible only with Python 3, but it is possible, with 
some limitations, to backport it to Python 2 (though it is not on my todo list).

There is a number of possible benefits for PySpark users and developers:

  *   Static analysis can detect a number of common mistakes to prevent runtime 
failures. Generic self is still fairly limited, so it is more useful with 
DataFrames, SS and ML than RDD, DStreams or RDD.
  *   Annotations can be used for documenting complex signatures 
(https://git.io/v95JN) including dependencies on arguments and value 
(https://git.io/v95JA).
  *   Detecting possible bugs in Spark (SPARK-20631) .
  *   Showing API inconsistencies.

Roadmap

  *   Update the project to reflect Spark 2.2.
  *   Refine existing annotations.

If there will be enough interest I am happy to contribute this back to Spark or 
submit to Typeshed (https://github.com/python/typeshed -  this would require a 
formal ASF approval, and since Typeshed doesn't provide versioning, is probably 
not the best option in our case).

Further inforamtion:

  *   https://github.com/zero323/pyspark-stubs - GitHub repository

  *   
https://speakerdeck.com/marcobonzanini/static-type-analysis-for-robust-data-products-at-pydata-london-2017
 - interesting presentation by Marco Bonzanini

--

Best,

Maciej


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