The Python v2 Tutorial

01 Hello, World!

Python v2 programs are plain text files ending in .pyv2. The print function shows things on screen, and # starts a comment.

# hello.pyv2
print("Hello, World!")
print("2 + 2 =", 2 + 2)

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On your computer, run it with python3 -m pyv2 hello.pyv2 — get the language here.

02 Variables & Values

Just write name = value — no declarations, no semicolons. Python v2 has numbers, strings, booleans, and nil (the “nothing” value). Ask type(x) whenever you're curious.

name = "Ada"
age = 36
pi = 3.14
coding = true
gift = nil

print(name, age, pi, coding, gift)
print(type(name), type(age), type(coding), type(gift))

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03 Math

All the usual operators, plus three you'll love: // is floor division, % is remainder, and ** is power. Division always gives you a real number — 10 / 4 is 2.5, not 2.

print(10 / 4, 10 // 4, 7 % 3, 2 ** 10)
print(-7 // 2, -7 % 3)        # floored, Python-style
print("n=" + 42)              # strings + numbers just work

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04 Strings & F-Strings

The star of the show: f-strings. Put f before a string and {anything} inside it — expressions included. Strings come with friendly methods: upper, split, contains, …

name = "python v2"
print(f"Hello, {name}!")
print(f"next year: {2026 + 1}, fast: {2 ** 8}")
print(f"{{braces}} survive when doubled")

print(name.upper(), name.title())
print("a,b,c".split(",").join(" - "))
print("hello".contains("ell"), "hello".slice(1, 3))

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05 Lists

Lists keep things in order. Index with xs[0] (or xs[-1] for the last), and use the methods that spark joy: push, sort, join, …

xs = [3, 1, 2]
xs.push(4)
print(xs, xs.sort(), xs[-1])

names = ["Ada", "Grace"]
names.insert(0, "Edsger")
print(names, names.join(", "), len(names))
print([1, 2] + [3], [1, 2] * 2)

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06 Maps

Maps hold labeled values. Bare keys become strings, dot access reads them, and get(key, default) never explodes when the key is missing.

hero = {
    name: "Ada",
    scores: [10, 20, 30],
}
hero.city = "London"

print(hero.name, hero["city"])
print(hero.scores)
hero.scores.push(40)
print(hero.scores)
print(hero.get("pet", "none"), hero.has("name"))

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07 Decisions

if / elif / else blocks end with end — no indentation errors, ever. And the ternary reads like a question: ok ? "yes" : "no".

score = 87

if score >= 90:
    grade = "A"
elif score >= 80:
    grade = "B"
else:
    grade = "C"
end

print(f"score {score} → grade {grade}")
print(score > 60 ? "passed" : "failed")

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08 Loops

for x in … walks lists, strings, maps and range(). while repeats until you say stop — with break and continue when you need them.

for i in range(1, 6):
    print(f"i is {i}")
end

total = 0
for n in [1, 2, 3, 4, 5, 6]:
    if n % 2 == 0:
        continue        # skip evens
    end
    total += n
end
print("sum of odds:", total)

for ch in "abc":
    print(ch)
end

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09 Functions & Closures

Define functions with fn, give values back with return. Functions are just values — pass them around. And inner functions remember the world they were born in (real closures, no nonlocal nonsense).

fn greet(name):
    return f"Hello, {name}!"
end

fn make_counter():
    n = 0
    fn bump():
        n += 1
        return n
    end
    return bump
end

print(greet("World"))

counter = make_counter()
counter()
counter()
print("count:", counter())

sq = fn(x): return x * x end
print("7² =", sq(7))

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10 Errors & Checks

When something goes wrong you get a clear message with the line number. Use assert to check things you care about — it's just a normal function.

fn divide(a, b):
    assert(b != 0, "b must not be zero")
    return a / b
end

print(divide(10, 2))
print(divide(1, 0))      # boom — read the error message!

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★ What's Next

You now know the whole language. Seriously — that was it. Go build something:

• Install it on your machine and run examples/fizzbuzz.pyv2.
• Read the docs — full builtin & method reference, plus editor setup.
• Play the CPU raycaster and then read examples/terminal_raycast.pyv2 — the whole engine in one file.
• Join the fun on GitHub — stars, issues and pull requests all accepted.

Graduation project: write FizzBuzz from memory, the Python v2 way —

for i in range(1, 16):
    if i % 15 == 0:
        print("FizzBuzz")
    elif i % 3 == 0:
        print("Fizz")
    elif i % 5 == 0:
        print("Buzz")
    else:
        print(i)
    end
end

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