Fix python warnings (occur during testing)

[menshikh-iv]

Need to fix warnings from interpreter (during test run).
It's easy to see all:
python -Wd -t -3 for python2
python -Wd -b for python3

[menshikh-iv]

I looked at it and realized that it makes no sense to do it separately. This can be done in the process of refactoring tests (in the future).

[poornagurram]

@menshikh-iv I would like to submit a PR for this. I am a beginner contributor. can you elaborate more on this?

[menshikh-iv]

@poornagurram of course, submit your PR.

[poornagurram]

@menshikh-iv I didn't get a clear idea about this issue can you elaborate more on this.

[menshikh-iv]

@poornagurram of course,

Firstly (for simple investigation) you need to run tests with python3 and enabled warnings, howto:

• Clone gensim repo
• Create clean venv
• pip install -e .[test] in gensim folder
• python -Wd -b setup.py tests

you'll see many different warnings (about unclosed files, division, etc), you need to go to concrete tests that generate this warning, fix warnings and submit PR.

[menshikh-iv]

Many ResourseWarning from smart_open, this part fixed in smart_open/140, another yet part fixed in #1660

[orsonadams]

Is this still a good beginner contrib issue? Would like to have a look. @menshikh-iv

[menshikh-iv]

@ParseThis this is a good issue for start, but need to make many small changes (if you have enough time - you are welcome)

[menshikh-iv]

I fixed almost all of it in #2191