The Programmer's Grimoire: learn to code, starting with Python

Install Python from python.org (on Windows the Microsoft Store copy is fine too). Open a terminal and check it answers: the version command below should print 3.something. Then type the interpreter name with no arguments and drop into the interactive prompt: this REPL is your sandbox, where every later incantation can be tested one line at a time. Finally, put two lines in a file named hello.py and run it with the file name. Congratulations: you have summoned and commanded.

$ python3 --version
Python 3.13.2
$ python3 hello.py
Hello, Azeroth

Variables are labeled jars; values have types. Learn str, int, float, and bool, and let f-strings carry your formatting. Ask the user for input (it always arrives as a string) and answer back. Ten minutes of this in the REPL teaches more than a chapter of reading.

name = "Chromie"
level = 60
print(f"{name} is level {level}")
print(int("60") + 1)   # types convert on purpose, never silently

Programs become programs when they decide. if, elif, and else choose paths; comparison operators produce booleans; and, or, and not combine them. Then loop: for walks a sequence, while repeats until a condition breaks. Write a number guessing game in fifteen lines; it uses everything in this rank.

for i in range(1, 4):
    print("cast", i)

if level >= 60 and name == "Chromie":
    print("the timeline holds")
else:
    print("keep leveling")

A function is a bound demon with a name: def creates it, arguments feed it, return brings back the result. Write many small functions instead of few large ones; if you can name it in three words, it should probably be a function. Learn default argument values, and learn that scope is real: a function sees its own variables and its parameters, not your scratchpad.

def heal(target, amount=10):
    """Return the heal message for a target."""
    return f"{target} healed for {amount}"

print(heal("tank"))
print(heal("party", 25))

Lists are ordered packs, dicts are spellbooks keyed by name, sets drop duplicates, tuples do not change. Master .append, .items(), in, and len first; comprehensions second: they build a new collection from an old one in one readable line. Almost all real data arrives as some nest of lists and dicts, so this rank pays for the whole apprenticeship.

spells = {"fireball": 3, "frostbolt": 2, "polymorph": 1}
for name, rank in sorted(spells.items()):
    print(f"{name}: rank {rank}")

maxed = [s.title() for s in spells if spells[s] >= 2]

Programs that remember things read and write files. The with-statement opens a file and guarantees it closes. Errors are not shame: they are the machine reporting reality, and try/except is how a program survives them without lying about what happened. Catch the specific error you expect (ValueError, KeyError, FileNotFoundError), never everything.

with open("journal.txt", "a") as f:
    f.write("day 1: summoned an imp\n")

try:
    level = int("sixty")
except ValueError:
    print("that was not a number, apprentice")

Classes bundle data with the functions that belong to it; import borrows ready-made power; and the ecosystem is the hoard. Learn to create a virtual environment and install from the package index: this is how you summon other summoners' demons without wrecking your own circle. Write one small class with an __init__ and two methods, then rewrite an earlier function-based exercise with it.

class Imp:
    def __init__(self, name):
        self.name = name

    def work(self, chore):
        return f"{self.name} sorted the {chore}"

imp = Imp("Pip")
print(imp.work("files"))

# $ python3 -m venv .venv && source .venv/bin/activate
# $ pip install rich  # then: import rich

The apprenticeship ends when something real exists. Climb the ladder: a command line tool you actually use (rename files, track a habit, tally expenses), then a scraper for a page you own, then a small web API or site. Put it under version control from day one, write three tests and run them with pytest, and publish the repository so the project has a public soul. Then read your own code from rank 1 and feel the distance.

$ git init && git add . && git commit -m "first summoning"
$ pytest -q
3 passed in 0.02s
$ # push it to a public code host: the project now exists