Is PyRun completely free to use?

Yes — PyRun is entirely free. There is no sign-up, no subscription, and no hidden limit. You can write and run Python code as many times as you like without creating an account.

Does PyRun work without an internet connection?

After the first load, PyRun continues to work offline. The Python engine (Pyodide) is cached locally by your browser, so you can keep coding even when you have no internet access. Some features like link sharing require a connection.

Which version of Python does PyRun use?

PyRun runs Python 3.11 via Pyodide, a port of CPython compiled to WebAssembly. You get access to the full Python standard library, including modules like math, json, datetime, itertools, and more.

Is my code private? Does PyRun store what I write?

Your code never leaves your device unless you explicitly generate a public share link. All execution happens entirely inside your browser sandbox. PyRun has no server that receives or stores your code.

Can I use PyRun on a phone or tablet?

Yes. PyRun is built with a responsive layout and works on mobile browsers. The interface adapts to smaller screens, switching to a stacked layout so both the editor and output terminal remain accessible.

Can I import and open my own Python files?

Absolutely. You can open any .py file from your device using the toolbar button or with the Ctrl+O keyboard shortcut. The file loads directly into the editor, ready to run.

How do I share my code with someone else?

Use the Share button in the toolbar or press Ctrl+H. PyRun generates a unique URL that encodes your code. Anyone with the link can open it in their browser and see (or run) the exact same code.

Does PyRun support the input() function?

Yes. PyRun has full support for Python's built-in input() function. When your code reaches an input() call, the terminal prompts you to type a response, just as it would in a local terminal.

Python Lists: Arrays, Methods and Iteration

Learn everything about Python lists. Discover how to create, slice, modify, and iterate through arrays in Python natively.

Try Python Lists Code

Overview

Lists are used to store multiple items in a single variable. Lists are one of 4 built-in data types in Python used to store collections of data.

Lists are ordered, changeable, and allow duplicate values. List items are indexed, the first item has index [0], the second item has index [1] etc.

You can append, remove, sort, and slice lists efficiently.

Code Example

Demonstrating initialization, indexing, modification and standard list iteration.

lists.py

Try in Editor

fruits = ["apple", "banana", "cherry"]

fruits.append("orange") # Add item
fruits[1] = "mango"     # Change item
fruits.sort()           # Alphabetical sort

print(f"List: {fruits}")
print(f"First fruit: {fruits[0]}")
print(f"Total fruits: {len(fruits)}")

Terminal Output

List: ['apple', 'cherry', 'mango', 'orange']
First fruit: apple
Total fruits: 4

Real-world Use Cases

Holding ordered collections like a queue of tasks
Accumulating data points over time
Implementing stacks and queues

Frequently Asked Questions

What is a list comprehension?

It is a shorter syntax when you want to create a new list based on the values of an existing list. Example: [x for x in fruits if "a" in x]

What is the difference between list and tuple?

Lists are mutable (changeable) while tuples are immutable (unchangeable). Tuples use parentheses ().

Keep Learning

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