So, now, in this code I will have no idea that is this, is this error from Airflow or somebody forget to remove from master code debug assert? So with normal error it will be like this:
*assert self.futures, NOT_STARTED_MESSAGE* *if not self.futures: * * raise AirflowException(NOT_STARTED_MESSAGE)* second variant: more readable, does not cause any issues with any flags, I see in traceback what kind of error is this - some random Apache Airflow or maybe ValueError, or maybe TypeError - I have more information as developer And at the end of the day '*debug*' tool not used in production code. On Tue, Dec 3, 2019 at 7:53 PM Jarek Potiuk <[email protected]> wrote: > Just an example of such asserts which IMHO are nicer are here: > > https://github.com/apache/airflow/pull/6596/files#diff-4c0c36f193f2cd65e2b55ba3102c1ba2R38 > One line assert with message. > > J. > > > > On Tue, Dec 3, 2019 at 5:36 PM Anton Zayniev <[email protected]> > wrote: > > > Hi, guys. I'm really surprised about this > > > > > - (+) asserts look nicer and are more readable than if (something): > > > throw Exception() > > > > I'm pretty sure that all the code I have encountered a way more readable > > using "if/else" or "try/except". But may be it is just me. Could you > > provide an example of code which is better with "assert"? > > > > - (+) asserts are especially good for cases like None exception - they > > > add more developer friendly messages when they will fail a few lines > > > below > > > with (for example) None has no property "dag". But it's ok if those > > get > > > optimised away. > > > > I think the best way to catch None is to ensure your code would fail > > conveniently. Like raising understandable Exception message, if you > believe > > that should be a point of confusion. > > > > On Tue, 3 Dec 2019 at 16:22, Iuliia Volkova <[email protected]> wrote: > > > > > Hi everyone, I'm usually not write anything in this mail list, but this > > > theme something really strange > > > Exist offissial doc: > > > > > > https://docs.python.org/3/reference/simple_stmts.html#the-assert-statement > > > > > > and there is a key information: Assert statements are a convenient way > to > > > insert debugging assertions into a program. > > > > > > *Debugging. * - this is a key propose of asserts keyword. > > > > > > there is no any type of possible asserts that cannot be done with > normal > > > Exceptions and Errors types that more explicit and detailed when > > 'assert' - > > > you have ValueError, TyperError and etc. what kind of problems must > > solved > > > DEBUG tools in production code that can be easily turned off on servers > > by > > > users? > > > > > > asserts used in tests and in process of debug code, not in production > > > > > > On Tue, Dec 3, 2019 at 6:47 PM Jarek Potiuk <[email protected]> > > > wrote: > > > > > > > We had a few discussions about using asserts in our code. I pasted > some > > > > links below but wanted to extract a gist of it. > > > > > > > > Here are the comments summarised: > > > > > > > > - (+) asserts look nicer and are more readable than if > (something): > > > > throw Exception() > > > > - (-) asserts can be optimized away with -O flag so we should not > > > based > > > > any real logic on having them > > > > - (+) asserts are good in cases that can happen in development but > > > > should "never happen" in reality > > > > - (+) asserts are especially good for cases like None exception - > > they > > > > add more developer friendly messages when they will fail a few > lines > > > > below > > > > with (for example) None has no property "dag". But it's ok if > those > > > get > > > > optimised away. > > > > > > > > We would like to discuss those points in community and have a > > community - > > > > driven decision on: > > > > > > > > 1) whether we should use asserts? > > > > 2) in which cases > > > > 3) in which cases we should NOT use asserts. > > > > > > > > J. > > > > > > > > The links here: > > > > > > > > Slack Discussion: > > > > > https://apache-airflow.slack.com/archives/CCQ7EGB1P/p1575364664041300 > > > > > > > > Github threads: > > > > > > > > - > https://github.com/apache/airflow/pull/6596#discussion_r352916409 > > > > - > https://github.com/apache/airflow/pull/6596#discussion_r352914727 > > > > - > > > > > > https://github.com/apache/airflow/pull/3690#pullrequestreview-143376629 > > > > > > > > Stack overflow link for asserts: > > > > > > > > - https://stackoverflow.com/a/1838411/5691525 > > > > > > > > > > > > > > > > > > > > > > > > J. > > > > > > > > -- > > > > > > > > Jarek Potiuk > > > > Polidea <https://www.polidea.com/> | Principal Software Engineer > > > > > > > > M: +48 660 796 129 <+48660796129> > > > > [image: Polidea] <https://www.polidea.com/> > > > > > > > > > > > > > -- > > > _________ > > > > > > С уважением, Юлия Волкова > > > Тел. : +7 (911) 116-71-82 > > > > > > > > -- > > Jarek Potiuk > Polidea <https://www.polidea.com/> | Principal Software Engineer > > M: +48 660 796 129 <+48660796129> > [image: Polidea] <https://www.polidea.com/> > -- _________ С уважением, Юлия Волкова Тел. : +7 (911) 116-71-82
