Add Bot Class

[xayhewalo]

Provide a useful bot class that future bots can inherit from. Also provide an example script.

[cclauss]

LGTM

[cclauss]

Should we drop support for Python 2?

[xayhewalo]

I'm stuck on the logging feature of the bot. Here's a truncated log from the failed test:

========================================================================= FAILURES ==========================================================================
_________________________________________________________ TestBots.test_save_when_dry_run_is_false __________________________________________________________

self = <tests.test_bots.TestBots testMethod=test_save_when_dry_run_is_false>, mock_sys_exit = <MagicMock name='exit' id='140352546728312'>

    @patch('olclient.bots.sys.exit')  # so that pytest doesn't exit
    def test_save_when_dry_run_is_false(self, mock_sys_exit):
        save_fn = Mock()
        bot = BaseBot(ol=self.ol, dry_run=False)
        old_changed = copy.deepcopy(bot.changed)
>       bot.save(save_fn)

test_bots.py:57: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
../olclient/bots.py:90: in save
    self.logger.info('Modification limit reached. Exiting script.')
/usr/lib/python3.5/logging/__init__.py:1279: in info
    self._log(INFO, msg, args, **kwargs)
/usr/lib/python3.5/logging/__init__.py:1415: in _log
    self.handle(record)
/usr/lib/python3.5/logging/__init__.py:1425: in handle
    self.callHandlers(record)
/usr/lib/python3.5/logging/__init__.py:1487: in callHandlers
    hdlr.handle(record)
/usr/lib/python3.5/logging/__init__.py:855: in handle
    self.emit(record)
/usr/lib/python3.5/logging/__init__.py:1047: in emit
    self.stream = self._open()
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <logging.FileHandler object at 0x7fa66038bb70>

    def _open(self):
        """
        Open the current base file with the (original) mode and encoding.
        Return the resulting stream.
        """
>       return open(self.baseFilename, self.mode, encoding=self.encoding)
E       FileNotFoundError: [Errno 2] No such file or directory: '<truncated>/openlibrary-client/olclient/logs/jobs/home/guyrandy/.local/bin/pytest/home/guyrandy/.local/bin/pytest_20200826_165250.log'

/usr/lib/python3.5/logging/__init__.py:1037: FileNotFoundError
------------------------------------------------------------------- Captured stderr call --------------------------------------------------------------------
jobs./home/guyrandy/.local/bin/pytest;INFO    ;2020-08-26 16:52:50,488 Modification limit reached. Exiting script.

I think the problem might be the logger is writing to jobs./home/guyrandy/.local/bin/pytest and pytest expects the file to be at /jobs/home/guyrandy/.local/bin/pytest/home/guyrandy/.local/bin/pytest_20200826_165250.log. Maybe that's not the case. I can't tell the forest from the trees at this point.

Simply intializing the bot used to throw this error, but then i set delay=True on line 53 of bots.py. Which delays the output of the file according to the python docs.

If delay is true, then file opening is deferred until the first call to emit(). By default, the file grows indefinitely.
Still, I'm just guessing at this point

[cclauss]

/usr/lib/python3.5/logging/__init__.py:1279: in info

Is the result identical on Python 3.7 or 3.8?

[xayhewalo]

Alas, I have found a solution! The problem was job_name = os.path.splitext(sys.argv[0])[0]. Since pytest is called by itself job_name == '' and pytest was getting confused. It had nothing to do with Python 3.5 vs 3.8. The test fails now because of unrelated MARC code.

Paging for @cdrini and @mekarpeles for review

[cdrini]

Ok! Some code cleanup things, but this is looking greeeeat!

[cclauss]

This looks good to me. All comments are OPTIONAL.

[cclauss]

I believe that we can comment out this line so the tests pass. ;-)

[cdrini]

Let's 🚀 this PR! Merging once travis done 👍

[cdrini]

You'll need to cleanup your master (why you should always use branches :) )

git checkout master
git fetch upstream master
git reset --hard upstream/master
git push origin HEAD