I was just wondering while reading my textbook how someone could write string-downcase for beginners in scheme? Thank so much!
I know how to do it using map but I was wondering if there was a more basic way to do it so that beginners to scheme can understand without knowing what map does. Thanks!
This time I'll write the general idea of the algorithm, you should know by now how to write this up using a template:
Transform the string to a list of characters, using string->list
Iterate over the list, and transform each character to lowercase using char-downcase
Build a new list with the newly transformed characters
Finally, transform back the resulting list using list->string
Basically we're mapping over the characters in the string. There are several fancy ways to do this, for instance using sequences, or map, etc. but for now, I believe is better that we stick to the basics and learn how to do this from scratch.
Related
I am using apache arrow golang library to read parquet. No-repeated column seems straight forward, but how can I read repeated field?
For reading repeated fields in Parquet there's really two answers: a complex way and an easy way.
The easy way is to use the pqarrow package and just read directly into an Arrow list array of some kind and let the complexity be handled for you. (https://pkg.go.dev/github.com/apache/arrow/go/v10#v10.0.1/parquet/pqarrow)
To read them the complex way, you have to understand repetition and definition levels and how Parquet uses them. Instead of trying to explain them here, I'm going to point you to the excellent write-up on the Apache Arrow blog here: https://arrow.apache.org/blog/2022/10/08/arrow-parquet-encoding-part-2/ which explains how to decode definition and repetition levels (yes it's in the context of the Rust implementation of Parquet, but the basic concepts are the same for the Go implementation).
All of the ColumnChunkReader types allow you to retrieve those Definition and Repetition levels in their ReadBatch methods. For an example have a look at https://pkg.go.dev/github.com/apache/arrow/go/v10#v10.0.1/parquet/file#Float32ColumnChunkReader.ReadBatch
When you call ReadBatch you can pass an []int16 for the definition levels and the repetition levels to be filled in alongside the data, and then you can use those to decode the repeated field accordingly. Personally, I prefer to use the pqarrow package which does it for you, but sometimes you do need the granular access.
I am starting to get acquainted with the use of ELK for work purposes, but struggle to find a solution to use simple mathematic requests in my database.
As shown on the picture, my DB contains 16 available fields, but I would like to create others, without doing it on Excel before converting my file in CVS again.
For example, I would like to create a variable #Bugs/Release. I've heard that this is quite easy to make with no need of scripting, but I can't find the way to do it... Has anybody the solution of this problem?
Huge thanksenter image description here
I am new to this site and I would like to get some inputs regarding parsing STDF files. Generally speaking, I am trying to parse a STDF file to gather only the results (numbers) and not the rest of the line. If I am able to achieve this, I would then like to compare all the numbers together through a bubble sort or insertion sort and see if any numbers are equal to each other. I am capable of doing this in C/C++ and Java but I have no experience parsing documents using Scripts.
Could anyone push me in the right direction? What should I be reading to learn my way around this?
Are you already using an STDF library?
You did not mention one, so I assume not.
You should find a library you are comfortable with (the list changes over time, but you can find some by Googling or looking at the STDF page on Wikipedia) rather than attempting to parse STDF yourself, unless you have a good reason to recreate the STDF parser wheel.
An STDF file contains many tests. It generally does not make sense to compare the results for different tests, so I assume you are looking for matching values within the set of results for each test.
I would use your chosen STDF parser to read the value of each test for each part. Keep a set of the results for each test. As you read each new result, check the set to see if already exists. If it does, you have found the case you were looking for, otherwise add the result to the set.
I'm totally new with programming, but have made some scripts for extraction data from .txt files etc. Now I am making a simple script for work, but need a simple GUI so people can run use it efficiently. The script is really simple, and consists of 4 dictionaries and a list with the keys for the values that I want to print from one of the dictionaries. What I need is a GUI that looks like the one posted. There will be 4 buttons, one for each dictionary, and the user can only pick one. On the left will be the keys, and the keys transferred to the right will be put in a list, which will be used to write the values to a .txt file. This is probably really simple, but I have no idea where to start with GUI, so I hope that someone can give me some ideas. In advance, thank you :)
Exaple: https://ci.apache.org/projects/wicket/guide/6.x/img/multi-select-transfer-component.png
It's cool that you are getting into GUI programming. Try tkinter:
https://www.tutorialspoint.com/python/python_gui_programming.htm
I'm trying to make an algorithm that easily simplifies and groups synonyms (with mismatches, capitals, acronims, etc) into only one. I supose there should exist a standard way to build such a structure that, looking for a string with possible mismatches, if the string exists in the structure, it returns a normalized string key. In short, sometimes the same concept could be written in several ways, but I only want to keep the concept.
For instance: Supose I want to normalize or simplify the appearances of
"General Director", "General Manager", "G, Dtor", "Gen Dir", ...
into
"GEN_DIR"
and keep only this result for further reference.
By the way, I suppose that building a Hash with key/value pairs like
hash["General Director"]="GEN_DIR"
hash["General Manager"]="GEN_DIR"
hash["G, Dtor"]="GEN_DIR"
hash["G, Dir"]="GEN_DIR"
could be a solution, but I suspect that there are more elegant or adequate solutions to that.
I would also need the way to persist this associative structure easily without any database because it should grow as I find more mismatches of the same word or sentence. A possible approach I think is to define this structure by means of a DSL, but I'm open to suggestions.
Well, there is no rule, at least a clear one.
My aim is to scrap from web some "structured" data that sometimes is incorrectly or incompletely typed. Some fields are descriptions and can be left as is. But some fields are suposedly to be "sets" but aren's correctly typed (as in my example). As a human can read that, he immediatelly knows what it means and can associate that with its meaning.
But I would like to automate as much as possible the process of reducing those possible mismatches to only one "string" (or symbol) before, for instance, saving it into a database. So, what I would need is a kindof hash or dictionary, as sawa correctly stated, that I can use to lookup any of such dirty strings to get the normalized string or symbol.
Also, of course, it would be desirable a way to make this hash (or whatelse it could be) to learn from new mismatches in some way and add a new association automatically (possibly it could be based on a distance measure between mismatched string and normalized string that, if lower than X, a new association is built). The whole association (i.e, hash) should grow as new mismatches and concepts arise and, though, it should be kept anywhere (possibly in an xml file, or something like what Mori answered below) for future uses.
Any new Idea?