Tag Archives: Carles Mateo Python teaching classes

News from the Blog 2022-01-22

News for the Blog

It has been 9 years since I created the blog, and some articles have old content that still get many visitors. To make sure they get the clear picture and not obsolete information, all the articles of the taxonomy POST, will include the Date and Time when the article was first published.

I also removed the annoying link “Leave a comment” on top. I think it influences some people to leave comments before actually having read the article.

It is still possible to add comments, but they are on the bottom of the page. I believe it makes more sense this way. This is the way.

Technically that involved modifying the files of my template:

  • functions.php
  • content.php

My Books

Automating and Provisioning to Amazon AWS using boto3 Amazon’s SDK for Python 3

I finished my book about Automating and Provisioning to Amazon AWS using boto3 Amazon’s SDK for Python 3.

It’s 128 pages in Full size DIN-A4 DRM-Free, and comes with a link to code samples of a real project CLI Menu based.

Docker Combat Guide

I have updated my book Docker Combat Guide and I added a completely new section, including source code, to work with Docker’s Python SDK.

I show the Docker SDK by showing the code of an actual CLI program I wrote in Python 3.

Here you can see a video that demonstrates how I launched a project with three Docker Containers via Docker compose. The Containers have Python, Flask webserver, and redis as bridge between the two Python Containers.

All the source code are downloadable with the book.

Watch at 1080p at Full Screen for better experience

My Classes

In January I resumed the coding classes. I have new students, and few spots free in my agenda, as some of my students graduated and others have been hired as Software Developers. I can not be more proud. :)

Free Training

Symfony is one of the most popular PHP Frameworks.

You can learn it with these free videos:


Software Licenses I Purchased

Before leaving 2021, I registered WinRAR for Windows.

WinRAR is a compressing Software that has been with us for 19 years.

I’m pretty sure I registered it in the past, but these holidays I was out only with two Window laptops and I had to do some work for the university and WinRAR came it handy, so I decided to register it again.

I create Software and Books, and I earn my life with this, so it makes a lot of sense to pay others for their good work crafting Software.

Books I Purchased

I bought this book and by the moment is really good. I wanted to buy some updated books as all my Linux books have some years already. Also I keep my skills sharp by reading reading reading.

Hardware I purchased

So I bought a cheap car power inverter.

The ones I saw in Amazon were €120+ and they were not very good rated, so I opted to buy a cheap one in the supermarket and keep it on the car just in case one day I need it. (My new Asus Zenbook laptop has 18 hours of autonomy and I don’t charge it for days, but you never know)

For those that don’t know, a power inverter allows you to get a 220V (120V in US) plug, from the connection of the lighter from your car. Also you can get the energy from an external car battery. This comes in really handy to charge the laptop, cameras, your drone… if you are in the nature and you don’t have any plug near.

I bought one years ago to power up Raspberry Pi’s when I was doing Research for a project I was studying to launch.


Many friends are using Starlink as a substitute of fiber for their rural homes, and they are super happy with it.

One of them send me a very fun article.

It is in Italian, but you can google translate it.


Anyways you can get the idea of what’s going on in the picture :)

So tell me… so your speed with Starlink drops 80% in winter uh… aha…

Random news about Software

I tried the voice recognition in Slack huddle, and it works pretty well. Also Zoom has this feature and they are great. Specially when you are in a group call, or in a class.

My health

I was experimenting some problems, so I scheduled an appointment to get blood analysis and to be checked. Just in case.

TL;TR I could have died.

The doctors saw my analysis and sent me to the hospital urgently, where they found something that was going to be lethal. For hours they were checking me and doing several more analysis and tests to discard false positives, etc… and they precisely found the issue and provided urgent treatment and confirmed that I could have died at any moment.

Basically I dodged a bullet.

I was doing certain healthy things that helped me in a situation that could have been deadly or extremely dangerous to my health.

With the treatment and my strict discipline, I reverted the situation really quick and now I have more health and more energy than before. I feel rejuvenated.

I’m feeling lucky that with my work, the classes, the books I wrote, etc… I didn’t have to worry about the expensive medicines, the transport, etc… It was a bad moment, during Christmas, with so many people on holidays, pharmacies and GPs closed, so I had to spend more time looking for, traveling, and to pay more than it would had been strictly necessary. Despite all the time I used to my health, I managed to finish my university duties on time, and I didn’t miss my duties at work after the hospital, neither I had to cancel any programming classes or mentoring sessions. Nobody out of my closest circle knew what was going on, with the exception of my boss, which I kept informed in real time, just in case there was any problem, as I didn’t want to let down the company and have my duties at work to be unattended if something major happened.

I was not afraid to die. Unfortunately I’ve lost very significant people since I was a child. Relatives, very appreciated bosses and colleagues which I considered my friends, and great friends of different circles. Illnesses, accidents, and a friend of mine committed suicide years ago, and some of my partners attempted it (before we know each other). When you see people that are so good leaving, this brings a sadness that cannot be explained with words. I have had a tough life.

We have a limited time, and he have freedom to make choices. Some people choose to be miserable, to mistreat others, to lie, to cheat, to be unfaithful, to lack ethic and integrity. Those are their choices. Their wasted time will not come back.

Some of my friends are doctors. I admire them. They save lives and improve the quality of life of people with health problems.

I like being an Engineer cause I can create things, I can build instead of destroy, I can help to improve the world, and I can help users to have a good time and to avoid the frustration of services being down. I chose to do a positive work. So many times I’ve been offered much bigger salaries to do something I didn’t like, or by companies that I don’t admire, and I refused. Cause I wanted to make a better world. I know many people don’t think like that, and they only take take take. They are even unable to understand my choices, even to believe that I’m like that. But it’s enough that I know what I’m doing, and that it makes sense for me, and that I know that I’m doing well. And then, one day, you realize, that doing well, being fair and nice even if other people stabbed you in the back, you got to know fantastic people like you, and people that adore you and love to have you in their life, in their companies… So I’m really fortunate. To all the good-hearted people around, that give without expect anything in return, that try to make the world a better place, thank you.

Python Programming class for beginners 2021-11-11

Suggested optional pre-requisites to have before the class

  • Install Python 3 (3.8 recommended, any version from Python 3.6 is fine)
  • Install PyCharm Community Edition or Professional Edition (is free for 30 days only)

Suggested optional reading material

Examples of the class today have been upload here

Material from some other classes

On this class, recorded on the video (1h 48m)

Why there are different types of variables

  • Memory
    • All are 0 and 1’s
  • How big can be a variable (float, integer, string)
  • Operations performed, like +
  • MT Notation I use

The order in which the instructions are performed (top to bottom).

  • Declaring a variable
  • We can call thinks that were previously defined up (like functions)
  • Loops will send the execution pointer up
  • Operations with integer variables
    • Additions
  • Operations with Strings

Language syntax and tricks (write a Notebook with your own notes)

  • Pre-created solutions, like reverse an string with for
  • Open a file, read the contents by lines to string, split the strings to arrays by a separator, like tab or space, get what you want by position.
with open(s_filename) as file:
    for s_line in file:

# Show Exceptions

# Show hexadecimal of the text:

# cd /home/carles/Desktop/code/carles/python-classes/2021-11-11

# hexdump -c text.txt

# remove enters, spaces at the end of the file with s_line.rstrip()

The blocks and functions

  • Indentation
  • Typical error missing :
  • Functions are for reusing code and reducing errors
    • As they are for reusing, they are flexible (parameters)

The while loop

  • The condition True
  • The condition in a variable
  • The condition in a if
  • Break
  • Pattern counter inside a loop

Building a Menu for user selection in text mode

  • Input
  • Validation


  • As part of the questions, a question about the mental process to Build the solution was raised.
    • TODO: Was explained
    • The importance of keeping Notes with snippets of code that you normally use one time and another
    • How to search in Google to find explanations in Python sites
  • A question was raised about how menus could be implemented using OOP
    • A parent Menu class, with a MenuAdmin class inheriting was demonstrated. The MenuAdmin inherits the menu options from the parent Menu, and adds Admin only options.

Some graphics with matplotlib

Recently I showed you how to generate a Cloud Tag.

You may like some of other graphs that can be easily generated with matlib package.

I’ve been always working on BackEnd and APIs and I don’t work on FrontEnd, although I programmed some videogames by myself and I’ve fixed some huge bugs in JavaScript in some of the companies I work, but they considered myself the last resource, so I would fix a FrontEnd bug when nobody else could. But even if you work 99.9% of your time in BackEnd, Scaling, Architecture… like me, it is useful being able to draw graphics, for example, when you create a tool that shows the number of players per minute, and its evolution over time, or web visitors in real time, etc…

I wrote this article with two simple examples for my book Python 3 exercises for beginners.

You can find this source code here:


import matplotlib.pyplot as plt

a_points1 = [7, 3, 15, 5, 10, 2, 9]
a_points2 = [2, 4, 9, 2, 7, 8, 4]



We can also add customized axis:


import matplotlib.pyplot as plt

a_points1 = [7, 3, 15, 5, 10, 2, 9]
a_points2 = [2, 4, 9, 2, 7, 8, 4]
a_points3 = [12, 10, 1, 7, 14, 16, 1]

a_days_of_the_week = ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"]

plt.plot(a_days_of_the_week, a_points1)
plt.plot(a_days_of_the_week, a_points2)
plt.plot(a_days_of_the_week, a_points3)
plt.grid(axis='y', color='black', linestyle='solid')

Draw a pie chart

import matplotlib.pyplot as plt

a_scores = [70, 20, 5, 5]
a_languages = ["Python", "Bash", "Java", "PHP"]
a_colors = ["Red", "Blue", "Green", "Cyan"]

plt.pie(a_scores, labels=a_languages, colors=a_colors)

This graphic represents in which languages I use my time nowadays, or if I update it by adding HTML and jQuery:


News from the blog 2021-09-07

  • Blocking Ip addresses in the firewall

I’ve been blocking entire ranges from Cloud Providers, as some of their Ip’s were being used to try to hack/abuse the blog.

After some time blocking individual Ip’s, I opted for being some more effective and blocking /24 (the class C for the offending Ip).

If you work for a CSP and you can’t see my blog from your range, this is the reason.

  • I have updated my two Python books.

For Python 3 simple exercises for beginners I’ve added this new content:

v.0.29 and v.0.28 Python 3 Simple Exercises for Beginners
Added a new section Games, with a first game “Guess my number”

Provided a solution for the recipe Exercise 3: Create a function that will ask a user for a number from Keyboard input, and return the result, only when the value is between the accepted ranges.

Added two new questions to the Quiz section.

Fixed a docstring in Recipes Exercise 4, referring to a String return value which it was an Integer.

Added an exercise for retrieving a JSON with your public Ip

Added a new exercise for converting bytes to kilobytes with two decimal positions.

Added a new exercise / recipe to SSH to a Server with Username and Password and execute a command, using the Paramiko library.

For Python 3 Combat Guide I have added this new content:

v.1.02 Python 3 Combat Guide

Added a new exercise / recipe to SSH to a Server with Username and Password and execute a command using Paramiko library. I added two examples executing commands uptime and df -h /

Show an alternative way to run Flask apps.

Added new interesting packages.

As long as covid is active I plan to keep the minimum price of each of my books at the minimum accepted by LeanPub which is USD $5.

I also enable bundles and enable LeanPub to make punctual discounts to make them even more affordable to humble pockets.

  • I’m going to teach an initiation to programming class, a live Zoom session of 1 hour, plus 15 minutes for questions, for Free. It will be a very basic starting class for absolute beginners.

It will be performed at a time around 19:00 Irish time, wich is 11:00 AM in Irivine, CA time, to maximize the opportunities for people to assist.

If you would like to join, write me an email:

There are not many spots available, but if there is no room for you this time I may contact you for the next time.

This version adds class StringUtils, and a set of methods to perform different useful tasks with Strings, like converting a number to the biggest unit with sense, like a large number of bytes to PB, a smaller one to TB, or GB, MB, KB, justifying strings to the right or to the left, and cap the number of chars to a specified one, etc…

I have many libraries that I’ve been building across the years, and I’m liberating them as Open Source, as soon as I have time to make sure that are compatible with Python 3.5 or superior (and with Python 2.6 when possible), and I have time to add a decent Unit Testing Code Coverage.

I try to release libraries that have no other dependencies. After that I’ll start releasing my libs that have dependencies, like to work with MySQL, SQLite, web scrapping, etc…

Video: Beginners Python: teaching to work with for, range, lists, dicts

I recorded this class where some university colleagues and few of my students joined me.

It is recorded at Full HD. Increase Youtube’s quality to make sure the video is smoothly displayed.

You can download the source code from a previous class and this one in Gitlab:


If you are looking for my technical books follow the link.

If you would like to become one of my students, or to have me as Mentor, check this section in my blog:

Classes and Mentor