[BEAM-1251] print() is a function in Python 3

[cclauss]

print() is a function in Python 3 # just like #4784, #5531, and #5890

@charlesccychen @holdenk @superbobry

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Post-Commit Tests Status (on master branch)

Lang	SDK	Apex	Dataflow	Flink	Gearpump	Samza	Spark
Go		---	---	---	---	---	---
Java
Python		---		---	---	---	---

[superbobry]

There seem to be two more occurences

sdks/python/apache_beam/io/tfrecordio_test.py
65:# ...   print data

sdks/python/apache_beam/utils/annotations.py
44:    print arg1, '*', arg2, '=',
55:    print arg1, '*', arg2, '(the old way)=',
63:    print arg1, '*', arg2, '(the experimental way)=',
69:  print multiply(5, 6)
70:  print old_multiply(5,6)
71:  print exp_multiply(5,6)

[cclauss]

Thanks @superbobry, those instances were in comments, not in live code but I have converted them for completeness.

[superbobry]

LGTM!

[cclauss]

@charlesccychen @holdenk Your reviews please?

[cclauss]

@pabloem Your review please?

[charlesccychen]

Thanks! This LGTM.

[cclauss]

@holdenk This is merged now but I am wondering how the testing did not catch this and how we can prevent similar regression in the future. https://github.com/apache/beam/blob/master/sdks/python/scripts/run_mini_py3lint.sh#L51 should be able to spot these as syntax errors but perhaps it is only look at a portion of the codebase instead of looking at all Python files in the repo. On Travis, it takes 20 sec to do this flake8 test on the entire repo.

[tvalentyn]

utils module is included py3 lint checks.

beam/sdks/python/tox.ini

Line 110 in f31b789

apache_beam/utils

I think the tools did not catch it because the occurrences are in the comment.

[cclauss]

The first three files contained print statements in live code. These files are in .test-infra/jenkins which flake8 does not currently test.