🐍 Python: From Zero to Automation, Networking and Cybersecurity

🌐 English | Español

A repository of exercises to learn Python from scratch, with a clear goal: to be able to automate tasks, write scripts and build networking and cybersecurity tools.

Each exercise comes with its own educational statement (which explains the new concepts) and my solution. Difficulty increases gradually, from a simple "Hello, how old are you?" up to a complete command-line tool.

📚 This is the continuation of my Bash exercises repository, using the same format.

---

🎯 Who is this repository for?

• For me, as a learning journal.
• For anyone who wants to learn Python starting from zero, with examples focused on networking and systems (IPs, ports, logs, passwords...) instead of generic ones.

ℹ️ The exercise statements (Enunciado.md) and code comments are currently written in Spanish.

---

📁 Structure

Python/
├── README.md
├── README.es.md
├── 01-fundamentos/
│   ├── 01-presentacion/
│   │   ├── Enunciado.md
│   │   └── solucion.py
│   └── 02-.../
├── 02-estructuras-datos/
├── 03-ficheros-sistema/
├── 04-redes/
├── 05-ciberseguridad/
└── 06-proyecto-final/

Each exercise folder contains:

File	Content
Enunciado.md	Goal, new concepts explained, hints and extra challenges
solucion.py	My solution to the exercise

---

▶️ How to run the exercises

Requirements: Python 3 (usually preinstalled on Linux/WSL2).

Check your version:

python3 --version

Run any solution from its folder:

cd 01-fundamentos/01-presentacion
python3 solucion.py

• python3 is the interpreter that reads and runs your code.
• solucion.py is the file containing the program.

My setup: WSL2 (Ubuntu) + Visual Studio Code.

---

🗺️ Learning path

Block 1 · Fundamentals (with a networking flavor)

#	Exercise	Concepts	Status
01	Introduction	input(), print(), int(), if/else	⏳
02	Basic calculator	operators, variables	⏳
03	Even or odd	% operator	⏳
04	Unit converter (bytes, MB, GB)	f-strings, decimals	⏳
05	Port classifier	if/elif/else, ranges	⏳
06	Multiplication table and countdown	for, range()	⏳
07	Guess the number	while, random	⏳
08	Validate an IP octet (0-255)	and/or, input validation with retries	⏳
09	Check password length	len(), strings	⏳
10	Interactive menu	while True, break, elif	⏳

Block 2 · Data structures and functions

#	Exercise	Concepts	Status
11	IP list manager	lists, append, remove	⏳
12	Port → service dictionary	dictionaries, .get()	⏳
13	Word counter	split(), dictionary as a counter	⏳
14	is_valid_ip() function	functions, return	⏳
15	Failed attempts per user	dictionary + for	⏳
16	Robust password validator	any(), string methods	⏳
17	Network device inventory	nested dictionaries	⏳
18	Filter and sort IPs by subnet	sorted(), list comprehensions	⏳

Block 3 · Files and system

#	Exercise	Concepts	Status
19	Read a file and count lines and words	open(), with, try/except	⏳
20	Journal/log with timestamps	modes "w"/"a", datetime	⏳
21	Analyze a simulated auth.log	files + dictionaries	⏳
22	Folder backup with date	shutil, pathlib	⏳
23	Organize files by extension	pathlib, shutil.move	⏳
24	Audit file permissions	os.walk, os.stat, stat	⏳
25	Run system commands	subprocess.run	⏳
26	Save and load the inventory (JSON/CSV)	json, csv	⏳

Block 4 · Networking

#	Exercise	Concepts	Status
27	Subnet calculator	ipaddress	⏳
28	Ping sweep	subprocess, ipaddress	⏳
29	TCP port scanner	socket	⏳
30	TCP client and server (echo)	socket, bind, listen	⏳
31	Query an API	requests, JSON, venv	⏳
32	Forward and reverse DNS lookup	socket, network errors	⏳
33	Run commands over SSH on a VM	paramiko, getpass	⏳
34	CLI tool with arguments	argparse	⏳

Block 5 · Defensive cybersecurity

#	Exercise	Concepts	Status
35	File hashing and integrity verification	hashlib	⏳
36	Folder integrity monitor	hashes, json, sets	⏳
37	Extract IPs and emails from a log	re (regex)	⏳
38	Brute-force detector with alerts	sliding window, datetime	⏳
39	Secure password generator	secrets, entropy	⏳
40	Check if a password has been leaked	k-anonymity, hashlib, requests	⏳
41	Basic packet sniffer	scapy	⏳
42	Encrypt and decrypt files	cryptography (Fernet)	⏳

Block 6 · Final project

A single project, toolkit: a defensive security tool with four modules (logs, audit, netmon, hids). See the block README for the architecture and how the phases work (statements are in Spanish).

#	Phase	Concepts	Status
43	Design and project skeleton	packages, pyproject.toml, argparse	⏳
44	Core: config, logging, alerts, reports	tomllib, logging, dataclasses	⏳
45	logs module: analyzer with alerts	regex, sliding window, collections	⏳
46	audit module: Linux security audit	stat, ss, hardening	⏳
47	netmon module: network monitor	ThreadPoolExecutor, baseline	⏳
48	hids module: mini HIDS	integration, watch, deduplication	⏳
49	Tests, packaging and final README	pytest, build, versioning	⏳

Legend: ✅ done · ⏳ pending

---

🧭 How to use this repository to learn

1. Read the exercise's Enunciado.md.
2. Try to solve it on your own using the concepts and hints.
3. Try the extra challenges.
4. Compare with solucion.py only at the end.

Making mistakes and debugging is the best part of learning. 💪

---

👤 Author

David · @misteralva · misteralva.github.io

ASIR student interested in networking, cybersecurity and automation.