Aijuh/182/log with logging

[Aijuh]

This closes #182.

I changed all codes using log channel into the codes using logging in poller.py, dbmgr.py, numger.py. Format using 'f' is changed to '%' in logging to prevent pylint error. All logs' level is logging.info. I think in cofig.json, channel name log should be deleted. But I leave it just in case.

[Aijuh]

I updated codes. Deleted backslash, and changed % format. As for error case message, all the number in logging, it has well defined range. So we cannot know error from its value. Otherwise I added logger messages for error cases if there was none.

[BECATRUE]

Oh, after you finish to apply our reviews, please re-request to us by clicking the above reviewers tab! It will make us check quickly.

[Aijuh]

I changed print to logger. But there is some issue.

I changed 'f' format including data type dictionary db to the '%' format as below by importing json. There might be bad thing by importing json or I misused it. logger.info("The message was ignored because " "the database %s has no such key; name or path.", json.dumps(db))

Also in examples/backend.py, I couldn't figure out what is e!r in print(f"apps.backend.write(): {e!r}"), so I just leave it as before. Can I just set it as logger.info("apps.backend.write(): %s", {e!r})?

[BECATRUE]

There might be bad thing by importing json or I misused it. logger.info("The message was ignored because " "the database %s has no such key; name or path.", json.dumps(db))

I think there is no problem because json.dumps() returns just a string!

[BECATRUE]

Can I just set it as logger.info("apps.backend.write(): %s", {e!r})?

I'm not sure, but I think it doesn't cause a problem. I couldn't find the detailed documentation about !r, but it looks another way to use repr(). In other words, e|r is the same as repr(e).

For more details, please see this documentation and this example. I think it is just a convention to print an exception.

[Aijuh]

Thank you for good reference. I changed {e!r} to %r.

[kangz12345]

For logging the exceptions, you can consider using exception(). This will (probably) print out the exception stack information as well.

[Aijuh]

Fix codes.

[Aijuh]

I agree with that. I will wait @kangz12345's comment.

[Aijuh]

I refer to logging 's log level. I understand error as problem in a particular function, and warning as possible problem. So In the code below I choose warning because two case has same function for now.

if self.dbNames[name]:
    logger.info("Database %s is set as %s.", name, self.dbNames[name])
else:
    logger.warning("Database %s is not selected.", name)

In the code below I use error because it has different function at that time.

for db in content.get("db", ()):
    if any(key not in db for key in ("name", "path")):
        logger.error("The message was ignored because "
                     "the database %s has no such key; name or path.", json.dumps(db))
        continue

[kangz12345]

I refer to logging 's log level. I understand error as problem in a particular function, and warning as possible problem. So In the code below I choose warning because two case has same function for now.

if self.dbNames[name]:
    logger.info("Database %s is set as %s.", name, self.dbNames[name])
else:
    logger.warning("Database %s is not selected.", name)

Actually in that case, I think info() is okay because it is a valid expected input (you can unselect the database). Of course, after all, databases should be determined so you can label it as a warning. Conclusion: you can decide which to use. I just wanted to tell you that it is not an unexpected situation.

[Aijuh]

Changed warning to info.

[Aijuh]

I will re-read changed code for later. Sorry for repeated error.

[BECATRUE]

I will re-read changed code for later. Sorry for repeated error.

It's okay😃 I will review the updated parts.

[Aijuh]

Code fixed.

[kangz12345]

Please apply the remaining parts that we discussed in snu-quiqcl/iquip#74.

Please describe the request in more detail.

[Aijuh]

I understand the request. I will update qiwis with respect to iquip.

[Aijuh]

I will first update until currently merged develop branch of iquip. Give me comments if you want further update.

[Aijuh]

Fixed the code.

[Aijuh]

I fixed it. I should have read it.