Online Python Tutor - Visualize Python, Java, and JavaScript code

What are shared sessions?

Language:

[coming soon!] Java options: pass in command-line arguments and feed user input to stdin

Python Examples

Basic: hello | happy | intro | filter | tokenize | insertion sort | for-else | user input

Math: factorial | fibonacci | memoized fibonacci | square root | gcd | towers of hanoi

Objects: OOP 1 | OOP 2 | OOP 3 | inheritance

Linked Lists: LL 1 | LL 2 | LL sum

Pointer Aliasing:
aliasing1 | aliasing2 | aliasing3 | aliasing4 | aliasing5 | aliasing6 | aliasing7 | aliasing8 | sumList

Higher-Order Functions:
closure1 | closure2 | closure3 | closure4 | closure5 | list map | summation | lambda param

Advanced:
list comp | list/set/dict comp | decorator | generator | genexpr | varargs | exception | metaclass

Python 3 only: student torture | nonlocal

Java Examples

Basic: Variables | ControlFlow | Sqrt | ExecLimit | Strings

Methods: PassByValue | Recursion | StackOverflow

OOP: Rolex | Person | Complex | Casting

Data structures: LinkedList | StackQueue | Postfix | SymbolTable

Java features: ToString | Reflect | Exception | ExceptionFlow | TwoClasses

Misc: Forest | Knapsack | StaticInitializer | Synthetic

(All Java examples created by David Pritchard)

JavaScript Examples

factorial | data types | exception | closure | shadowing | constructor | inheritance

Click the button above to create a permanent link to your visualization. To report a bug, paste the link along with a brief error description in an email addressed to philip@pgbovine.net

To embed this visualization in your webpage, click the 'Generate embed code' button above and paste the resulting HTML code into your webpage. Adjust the height and width parameters as needed.

Online Python Tutor currently supports three languages (despite its name!):

1. Python 2.7 and 3.3 with limited module imports and no file I/O. The following modules may be imported: bisect, collections, datetime, functools, heapq, itertools, json, math, operator, random, re, string. Backend source code.

2. Java using OpenJDK Java 7. The original Java visualizer was created by David Pritchard and Will Gwozdz. It supports StdIn, StdOut, most other stdlib libraries, Stack, Queue, and ST. (To access Java's built-in Stack/Queue classes, write import java.util.Stack; — note, import java.util.*; won't work.) Original source code: for the backend and for the frontend and installation instructions.

3. JavaScript running in Node.js v0.10.25 in ES5 strict mode. Backend source code.

By using Online Python Tutor, your visualized code, options, user interactions, and IP address are logged on our server and may be analyzed for research purposes. Nearly all Web services collect this basic information from users. However, Online Python Tutor does not collect any personal information, cookies, or session state.

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Copyright © Philip Guo. All rights reserved.