lxml VS Ruby on Rails

lxml

Parsel is a library build to extract data from XML/HTML documents with XPath and CSS selectors support, and could be combined with regular expressions. It's usees lxml parser under the hood by default.

So, now that I no longer work in that industry, and I had some free time, I created a lazy parsing package using lxml instead of the xml parser in the standard library, which can help people who want to have a python only parsing solution.

Seriously, use LXML.

I got curious about this now so I did some tests on my own, and it appears that the XML parser implementation in Python does indeed strip all newline characters from attributes. Whether this is according to XML standard I do not know; I also briefly tried an alternative XML implementation for Python and it behaves the same, so I would assume that this is standard behavior, but I'm not knowledgable enough about XML to say for certain.

I use lxml for the XML parsing and pyodbc as the ODBC library. We have a small team so I just keep it as simple as possible: 1. A cursor yields the XML documents from a SQL query as a stream 2. A generator function parses the XML document and yields the rows (you could parallelize this step) 3. Stream each of the resulting rows to a single CSV file 4. Scoop up the resulting CSV file into the target database (usually with the DB engine's loader; bulk insert isn't so fast over ODBC) It ends up being a straight forward, low-overhead approach.

If that sounds too weird maybe take a look at pycomm3, python also has lxml as well as requests. You could write a script that retrieves the data from the clx using the appropriate pycomm3 driver for cplx and then do xml things with the data using lxml and transmit the data over http using requests.

[0] is a my favorite demonstration of it.

[0]: https://github.com/rails/rails/commit/b83965785db1eec019edf1...

Here's a real life example: Imagine a Ruby on Rails app on which a team of developers are working. The code is hosted on GitLab and all the work is coordinated using GitLab issues. In other words: For every commit, there's an associated issue and the issue number acts as a sort of primary key for documentation, time reporting and so forth. This convention has a few advantages, most notably the ability to easily learn more about how, when and by whom features were implemented as well as how this implementation came to be.

Ruby on Rails is regarded as one of the best ruby frameworks. It was the primary language in developing big projects such as Twitter and helped the language boost the community. Often referred to as “Rails,” Ruby on Rails is a web development framework with an MVC control structure and currently running its 6.1 version. The 16-year-old language has dramatically influenced the web development structures and managing databases, web pages, and other components on a web application.

In Rails 7.1, a new option _instance_methods is introduced, allowing developers to opt-out of the automatic generation of instance methods for enums. When enum is defined with _instance_methods: false, Rails will no longer generate methods like pending?, processed?, etc.

Rails isn't super opinionated about database writes, its mostly left up to developers to discover that for relational DBs you do not want to be doing a bunch of small writes all at once.

That said it specifically has tools to address this that started appearing a few years ago https://github.com/rails/rails/pull/35077

The way my team handles it is to stick Kafka in between whats generating the records (for us, a bunch of web scraping workers) and and a consumer that pulls off the Kafka queue and runs an insert when its internal buffer reaches around 50k rows.

Rails is also looking to add some more direct background type work with https://github.com/basecamp/solid_queue but this is still very new - most larger Rails shops are going to be running a second system and a gem called Sidekiq that pulls jobs out of Redis.

I'm looking forward to see what extractions from this will land on rails. For example: https://github.com/rails/rails/issues/50454

Here is what strict_loading does (source):

Kamal is a wonderfully simple way to deploy your applications anywhere. It will also be included by default in Rails 8. Kamal is trivial, but I don’t recommend using it on your development machine.

Here's the GitHub milestone I've based this article on — https://github.com/rails/rails/milestone/87