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Python, visualised

See your code move.

Write Python and watch every line execute on a table of blocks — variables, lists, dicts, pointers and the call stack, one step at a time. No more guessing what print left out.

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36
levels
82
ranked solutions
0
installs — runs in your browser
bubble_sort.py

                

                
Decode
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How it reads

                
A tiny CPU for every line.

                
Real processors fetch an instruction, decode it, then execute it. codeart does the same for your Python, so cause and effect are never more than one step apart.

            

            
    
                
  1. 
                    01 · Fetch
                    
    Find the line
    
                    
    The editor highlights exactly which line runs next — loops, branches and function calls included.
    
                
    2. 
                
  2. 
                    02 · Decode
                    
    Say what it means
    
                    
    Plain-English operations: APPEND 7 → end of nums, SWAP arr[0] ⇄ arr[1], need in seen → True.
    
                
    3. 
                
  3. 
                    03 · Execute
                    
    Watch memory change
    
                    
    Blocks drop into lists, hop when swapped and fly into variables. Stack frames pile up and pop. Scrub backwards any time.
    
                
    4. 
            

        


        

            

                
Every problem, ranked

                
Brute force to optimal, side by side.

                
Each level comes with several approaches, tagged by what they optimise for. Animate any of them and compare the work they do on the same input.

            

            

                
EasyClimbing Stairsclimb_stairs(5)

                

                    ★ Optimal
                    
Two rolling variablestime O(n) · space O(1)

                    
14 steps
                

                

                    Best time
                    
Bottom-up tabletime O(n) · space O(n)

                    
26 steps
                

                

                    Brute force
                    
Plain recursiontime O(2ⁿ) · space O(n)

                    
47 steps
                

            

        


        

            

                
The path

                
From your first variable to dynamic programming.

            

            

        


        

            
Stop imagining memory.
Look at it.

            Start level one