Today I Learned

To debug a Node.js application, one can use the debugging built-in method:

(1) Insert debugger; statement where you want to insert a break point
(2) Run the file with command $ node inspect <file name>
(3) Use a key for example, c to continue to next break point

You can even debug values associated to variables at that break point by typing repl. For more information, Please check the official guide.

AWS Simple Email Service

Aws

Amazon Simple Email Service (SES) is a cost-effective email service built on the reliable and scalable infrastructure that Amazon.com developed to serve its own customer base. With Amazon SES, you can send transactional email, marketing messages, or any other type of high-quality content to your customers

AWS Textract

Aws

Service to extract text information with precision using an AWS service:

Amazon Textract is a machine learning (ML) service that automatically extracts text, handwriting, 
design elements and data from scanned documents.
It goes beyond simple optical character recognition (OCR) to identify,
understand and extract specific data from documents.

Source:https://aws.amazon.com/es/textract/

Print full object

Javascript

You can print the full object with all the child nodes of an object using:
console.dir(body, { depth: null });

Skip Typescritp check

Typescript

You can add this line at the beginning of a file to ignore all checks:

// @ts-nocheck

// @ts-expect-error

To skip only the next line.

React enviorment variables need REACT_APP_YOUR-VARIABLE-NAME to works in production/stagin servers

React

https://create-react-app.dev/docs/adding-custom-environment-variables/

Law of Demeter with multiple dots

Ruby On Rails

The Law of Demeter belongs to the principle that states in a ruby method of an object should invoke only the methods of the following kinds of objects:

itself
its parameters
any objects it creates/instantiates
its direct component objects

The law restricts how deeply a method can reach into another object’s dependency graph, preventing any one method from becoming tightly coupled to another object’s structure.

Multiple Dots

The most obvious violation of the Law of Demeter is “multiple dots,” meaning a chain of methods being invoked on each others’ return values.

class User
  def discounted_plan_price(discount_code)
    coupon = Coupon.new(discount_code)
    coupon.discount(account.plan.price)
  end
end

The call to account.plan.price above violates the Law of Demeter by invoking price on the return value of plan. The price method is not a method on User, its parameter discount_code, its instantiated object coupon or its direct component account.

The quickest way to avoid violations of this nature is to delegate the method:

class User
  def discounted_plan_price(discount_code)
    account.discounted_plan_price(discount_code)
  end
end

class Account
  def discounted_plan_price(discount_code)
    coupon= Coupon.new(discount_code)
    coupon.discount(plan.price)
  end
end

In a Rails application, you can quickly delegate methods using ActiveSupport’s delegate class method:

class User
  delegate :discount_plan_price, to: :account
end

If you find yourself writing lots of delegators, consider changing the consumer class to take a different object

Flask Blueprint

Flask

A Blueprint is a way to organize a group of related views and other code.
Rather than registering views and other code directly with an application, they are registered with a blueprint.
Then the blueprint is registered with the application when it is available in the factory function.

Find index of element in array

Python

You can use the method Array.index() to find the position of an element, example:

languages = ["English", "Spanish", "French"]
current_lang = "Spanish"

try:
  # Use the index() method to find the index of the element
  index = languages.index(current_lang)
  print(f"The index of '{current_lang}' in the languages list is: {index}")
except ValueError:
  print(f"'{current_lang}' is not found in the languages list.")

View package info

Npm

This command shows data about a package and prints it to stdout.

As an example, to view information about the connect package from the registry, you would run:

npm view connect

And you can see all versions using:

npm view connect versions

Parse Object to String

Python

Using json.dumps()
Similar to JavaScript's JSON.stringify(), Python offers json.dumps() to convert a Python object into a JSON string. This is the preferred method for most scenarios as JSON is a widely used and well-structured format.

import json

my_object = {"name": "Alice", "age": 30, "city": "New York"}
json_string = json.dumps(my_object)

print(json_string)  # Output: {"name": "Alice", "age": 30, "city": "New York"}

List images

Docker

You can use the command:

docker image ls

Convolutional Neural Networks (CNNs)

Convolutional Neural Networks (CNNs) are a specific type of deep learning architecture that excels at tasks involving images, videos, and other grid-like data. They are particularly successful in applications like image classification, object detection, and image segmentation.

Imagine you're looking at a picture of a cat. Our brains are good at recognizing the shapes of ears, whiskers, and fur to tell it's a cat. Convolutional Neural Networks (CNNs) are like artificial brains for computers, especially good at understanding pictures and videos.
Here's the basic idea:

CNNs look at images in small squares, like a detective examining a crime scene with a magnifying glass.
They learn what patterns are important in each square, like edges, shapes, and colors.
By putting these clues together, CNNs can eventually recognize the whole picture, just like you can recognize the cat.

This makes CNNs super useful for:

Telling what's in a picture (cats, dogs, cars, etc.)
Finding specific objects in a picture (like finding a cat in a photo of your living room)
Understanding videos (like what's happening in a security camera recording)

runtime.txt

Python

To specify a Python runtime, add a runtime.txt file to your app’s root directory that declares the exact version number to use.

$ cat runtime.txt
python-3.12.4

Source: https://devcenter.heroku.com/articles/python-runtimes

enumerate

Python

In Python, if you want to access the index while iterating over a sequence (like a list), you can use the built-in function enumerate().
Here’s how you can do it:

xs = [8, 23, 45]
for index, x in enumerate(xs):
    print(f"item #{index + 1} = {x}")

This will give you the desired output:

item #1 = 8
item #2 = 23
item #3 = 45