Data cleaning steps

Paste a CSV, then add cleaning steps in order, like a Java stream: each step takes the result of the one above. You see the row count after every step, the preview, and the pandas code for the same steps. Everything runs in your browser; nothing is uploaded.

1. Input

Paste CSV with a header row, or upload a .csv file (up to 5 MB, 50,000 rows).

What the input looks like

2. Steps

Add steps in order. The column names offered are the ones left after the steps above.

Fields marked * are required. A field that is wrong turns red.

    3. Result

    As pandas code

    The same steps written for pandas. Check it against the preview: a few steps differ slightly, for example how whitespace counts as missing.

    
  
    

  
    
    
    Questions
    
    
    What counts as missing?
    A cell that is empty or only spaces. Values such as NA are not missing until you replace them, so add a Replace step first if your file uses NA.
    
    
    Why does the order of steps matter?
    Each step changes the table the next one sees. Remove duplicates before you fill the missing values, and the median is worked out without the repeated rows.
    
    
    Can I use the steps again on another file?
    Yes. Download the steps as JSON and keep them. The same steps on the same file always give the same result.
    
    
    Is my data uploaded anywhere?
    No. The file is read and cleaned in your browser, and nothing is sent to a server.