salsa | generic framework for on-demand , incrementalized computation | Reactive Programming library

I have a dataframe with prices in $. I want to do calculations on it but the $ makes it impossible. I'm trying to remove it using df.iloc[:, 4].replace("$", " ", regex=True) but unfortunately nothing changes. If I add inplace=True then whe whole word disappears. What am I doing wrong? Tried many stackoverflow posts but nothing works. I cant use str.replace() because its about the whole column not one word.

My code:

I have a simple list where I'm displaying a looped Select using .map.

Everything is working fine, but the initial default value of each select is not what I have in my array list.

How do I set a defaultValue for each select in the list?

https://codesandbox.io/s/festive-robinson-847oj?file=/src/App.js:0-1435

I have a list in React where I'm using .map to render a loop from an array of elements.

The radio inputs are working perfectly, everyone is independent of the others, but I can't do the same for Select.

The Select area is changing in every field, I want it to change to it specified field like I did for the options.

I tried to re-use the same handleChange that I used in the radios for it and instead I had this error.

So i have a dataframe with two columns: artistID and genre:

This code is creating a hmtl form where you can select some chekcboxes and design a Taco. I am trying to perform model fields validation but it is not working. This code for example is supposed to return an error if the input field box of the name is empty or if no checkboxes are selected at all. The error variable in the controller though never catches any errors. What could possibly be happening. This code a copy paste example from the Spring in Action book so I'm not sure why it's not working.

Model

I have the following code

Repo

Attempt

After reading a large json file and capturing only the 'text' column, I would like to add a column to dataframe and set all rows to a specific value:

I am in the first steps of making a basic app following the book Spring in action, fifth edition. But right now I am seeing the following error message in browser, and no logs are printed in console. Below are the code:

Controller method:

This is the current design of the SQL Server database I am working with.

I have two tables:

1. recipes

1. recipe ingredients

Recipes consist of recipe ingredients but an ingredient can be another recipe. In theory there are infinite levels as each recipe can have another ingredient that is also a recipe.

In the above data example, the Fresh Salsa recipe (ID 3047) has 7 ingredients. Six are raw Materials but one is another recipe (Recipe ID 3008). This recipe ID references another recipe in the 'recipes' table.

There is no hierarchy and I don't think I can create a hierarchy.

The goal is to extract all the recipe items for a particular recipe that have a 'sub' recipes and 'sub-sub' recipes etc.

It would seem like a recursive lookup would be the answer but because there is no hierarchy, this doesn't seem to work.

Here's my attempted query (the recipeItem list variable is a list of all the recipeitems that are also recipes created in a previous query):