I like programming and anime.

I manage the bot /u/mahoro@lemmy.ml

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Joined 1 year ago
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Cake day: June 12th, 2023

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  • I also like the POSIX “seconds since 1970” standard, but I feel that should only be used in RAM when performing operations (time differences in timers etc.). It irks me when it’s used for serialising to text/JSON/XML/CSV.

    I’ve seen bugs where programmers tried to represent date in epoch time in seconds or milliseconds in json. So something like “pay date” would be presented by a timestamp, and would get off-by-one errors because whatever time library the programmer was using would do time zone conversions on a timestamp then truncate the date portion.

    If the programmer used ISO 8601 style formatting, I don’t think they would have included the timepart and the bug could have been avoided.

    Use dates when you need dates and timestamps when you need timestamps!


  • Do you use it? When?

    Parquet is really used for big data batch data processing. It’s columnar-based file format and is optimized for large, aggregation queries. It’s non-human readable so you need a library like apache arrow to read/write to it.

    I would use parquet in the following circumstances (or combination of circumstances):

    • The data is very large
    • I’m integrating this into an analytical query engine (Presto, etc.)
    • I’m transporting data that needs to land in an analytical data warehouse (Snowflake, BigQuery, etc.)
    • Consumed by data scientists, machine learning engineers, or other data engineers

    Since the data is columnar-based, doing queries like select sum(sales) from revenue is much cheaper and faster if the underlying data is in parquet than csv.

    The big advantage of csv is that it’s more portable. csv as a data file format has been around forever, so it is used in a lot of places where parquet can’t be used.


  • Wow everyone seems to love P3 but I actually liked P4 better. I mean I really enjoyed both, but P4 was a more immersive experience for me. I should reboot my vita and play it again.

    I really felt like P4 had deeper connections and relationships between the characters. It felt more real, and that made the tension in the game more exciting. I love every second of it and am still trying to find a game like it.

    Don’t get me wrong, P3 was great also. The gameplay was superb and the characters were all great. But P4 still has a special place in my heart.





  • Dude, if you’re being obtuse on purpose because you have an ax to grind against Rust, try a different approach. You’re not getting anywhere, clearly by the fact that no one agrees with you.

    If you don’t like that Rust has a restricted trademark, then call that out instead of trying to label the software and it’s license as non-free. It’s literally called out in my source that name restrictions ipso facto does not violate freedom 3.

    But if you genuinely believe that the implementation of the Rust language and it’s trademark is burdensome to create a fork, and you want people to believe you, then you gotta bring receipts. Remember, the benchmark that we both quoted is that it “effectively hampers you from releasing your changes”. It being “not a piece of cake” doesn’t cut it.

    Hint: Google Rust forks since their existence also undermines your claim.

    Good luck.








  • Story time:

    There was a long data pipeline that produced wrong results. The wrong results were subtle but reproducible. Each run was about an hour long in dev, and there was no intermediate data set. It takes some input, runs for an hour, and produces an output.

    The code was inherited and was a bit of a mess. Instead of digging through the code, I re-ran the pipeline through from about 6 months ago when we knew there was know bug. It was about 100+ commits since that time.

    Mind you, the bug could’ve been anywhere in the codebase as far as I was concerned.

    Took about a day of git bisect to narrow it down… to nothing. I found out that running code from the first commit from 6 months ago also produced incorrect data. Oops. That’s weird though because the code was running correctly back then.

    A few days of debugging later, and I eventually found the culprit: a dependency package got bumped a couple weeks back. Some sort of esoteric parser had a bug but didn’t fail. It incorrectly parsed some data after the bump. Going back a version fixed the bug.

    So yeah, git bisect killed about a day of my time.