Playground

A blank Python 3.14, running in this tab. Nothing is uploaded, nothing is installed, and what you type is saved in this browser for next time.

Scratch pad Python

# A blank page. Write whatever you like, then press Run. # # Your code is saved in this browser, so it will still be # here when you come back. from collections import Counter text = """the quick brown fox jumps over the lazy dog the quick brown fox is quick""" counts = Counter(text.split()) for word, count in counts.most_common(5): print(f"{word:8} {count}")

Things worth knowing

The first run is slow. Python itself has to arrive — about 11 MB, once, then cached by your browser. Every run after that starts instantly.
input() really blocks. The prompt appears in the output and the program waits. Enter sends a line; the EOF button ends input.
Runaway loops are safe. Code runs in a worker, so Stop can always kill it — the page itself never freezes.
Some things are missing. A browser has no threads, no subprocess and no raw sockets, so those parts of the standard library will not work here. Everything else does.

Copy a starting point

Ask a question

name = input("What is your name? ")
print(f"Hello, {name}!")

Read and write a file

with open("notes.txt", "w") as f:
    f.write("line one\nline two\n")

with open("notes.txt") as f:
    for n, line in enumerate(f, 1):
        print(n, line.rstrip())

Work with JSON

import json

data = {"name": "Ada", "tags": ["python", "maths"]}
text = json.dumps(data, indent=2)
print(text)
print(json.loads(text)["tags"][0])

Time some code

import time

start = time.perf_counter()
total = sum(i * i for i in range(1_000_000))
elapsed = time.perf_counter() - start

print(total)
print(f"{elapsed * 1000:.1f} ms")