CircuitPython is a derivative of MicroPython designed to simplify experimentation and education on low-cost microcontrollers. It makes it easier than ever to get prototyping by requiring no upfront desktop software downloads. Simply copy and edit files on the CIRCUITPY drive to iterate.
Follow this quick step-by-step for super-fast Python power :)
For more detailed info on installing CircuitPython, check out Installing CircuitPython.