# CircuitPython 101: Working with Lists, Iterators and Generators ## Overview ![](https://cdn-learn.adafruit.com/assets/assets/000/062/199/medium800/robotics___cnc_circuitpython_blinka-small.png?1537453729) This guide is part of a series on some of the more advanced features of Python, and specifically CircuitPython. Are you new to using CircuitPython? No worries, [there is a full getting started guide here](https://learn.adafruit.com/welcome-to-circuitpython). Adafruit suggests using the Mu editor to edit your code and have an interactive REPL in CircuitPython. [You can learn about Mu and its installation in this tutorial](https://learn.adafruit.com/welcome-to-circuitpython/installing-mu-editor). CircuitPython gets far more interesting when used with [the new SAMD51 (M4) based boards](https://www.adafruit.com/?q=m4) and the [Raspberry Pi](https://www.adafruit.com/product/3055). Not only do they have much higher clock speeds, they also have much more RAM. CircuitPython programs run significantly faster as a result, and they can be much larger and/or work with much more data. With this space comes the capability to move beyond simple scripts to more elaborate programs. The goal of this series of guides is to explore Python's mechanisms and techniques that will help make your more ambitious CircuitPython programs more manageable, understandable, and maintainable. In [CircuitPython 101: Basic Builtin Data Structures](https://learn.adafruit.com/basic-datastructures-in-circuitpython) we learned about Python's list data structure. We saw how to manipulate them and how to create literal instances. In [CircuitPython 101: Functions](https://learn.adafruit.com/circuitpython-101-functions) we learned about lambdas, which are single expression functions that don't have a name assigned to them. In this guide we'll explore some features of Python for working with lists: some list processing functions and _list comprehensions._ Then we'll go beyond simple lists with _iterators_ and _generators_. - [Next Page](https://learn.adafruit.com/circuitpython-101-list-and-things-iterators-generators/list-functions.md) ## Featured Products ### Adafruit Metro M4 feat. Microchip ATSAMD51 [Adafruit Metro M4 feat. Microchip ATSAMD51](https://www.adafruit.com/product/3382) Are you ready? Really ready? Cause here comes the fastest, most powerful Metro ever. The **Adafruit Metro M4** featuring the **Microchip ATSAMD51**. This Metro is like a bullet train, with its 120MHz Cortex M4 with floating point support. Your code will zig and zag... In Stock [Buy Now](https://www.adafruit.com/product/3382) [Related Guides to the Product](https://learn.adafruit.com/products/3382/guides) ### Adafruit Feather M4 Express - Featuring ATSAMD51 [Adafruit Feather M4 Express - Featuring ATSAMD51](https://www.adafruit.com/product/3857) It's what you've been waiting for, the Feather M4 Express featuring ATSAMD51. This Feather is fast like a swift, smart like an owl, strong like a ox-bird (it's half ox, half bird, OK?) This feather is powered by our new favorite chip, the **ATSAMD51J19** -  with... In Stock [Buy Now](https://www.adafruit.com/product/3857) [Related Guides to the Product](https://learn.adafruit.com/products/3857/guides) ### Adafruit ItsyBitsy M4 Express featuring ATSAMD51 [Adafruit ItsyBitsy M4 Express featuring ATSAMD51](https://www.adafruit.com/product/3800) What's smaller than a Feather but larger than a Trinket? It's an **Adafruit ItsyBitsy M4 Express** featuring the **Microchip ATSAMD51**! Small, powerful, with a ultra fast ATSAMD51 Cortex M4 processor running at 120 MHz - this microcontroller board is perfect... Out of Stock [Buy Now](https://www.adafruit.com/product/3800) [Related Guides to the Product](https://learn.adafruit.com/products/3800/guides) ## Related Guides - [Adafruit Metro M4 Express featuring ATSAMD51](https://learn.adafruit.com/adafruit-metro-m4-express-featuring-atsamd51.md) - [Adafruit Feather M4 Express](https://learn.adafruit.com/adafruit-feather-m4-express-atsamd51.md) - [Square NeoPixel Display with Black LED Acrylic](https://learn.adafruit.com/sqaure-neopixel-display-with-black-led-acrylic.md) - [3D Printed LED Buckle](https://learn.adafruit.com/3d-printed-led-buckle.md) - [MakeCode Arcade with SAMD51 M4](https://learn.adafruit.com/makecode-arcade-with-samd51-m4.md) - [Party Parrot Zoetrope](https://learn.adafruit.com/party-parrot-zoetrope.md) - [How to train new TensorFlow Lite micro speech models](https://learn.adafruit.com/how-to-train-new-tensorflow-lite-micro-speech-models.md) - [Introducing Adafruit Feather](https://learn.adafruit.com/adafruit-feather.md) - [Prop-Maker Keyblade](https://learn.adafruit.com/propmaker-keyblade.md) - [CircuitPython 101: Functions](https://learn.adafruit.com/circuitpython-101-functions.md) - [Extending CircuitPython: An Introduction](https://learn.adafruit.com/extending-circuitpython.md) - [CircuitPython 101: Basic Builtin Data Structures](https://learn.adafruit.com/basic-datastructures-in-circuitpython.md) - [Glitter Positioning System](https://learn.adafruit.com/glitter-positioning-system.md) - [Controlling Objects in Unity with a 9 DoF Sensor and Arduino](https://learn.adafruit.com/controlling-objects-in-unity-with-arduino.md) - [NeoTrellis Sound Board](https://learn.adafruit.com/neotrellis-soundboard.md) - [Simple Vertical Wordclock](https://learn.adafruit.com/vertical-wordclock.md) - [CircuitPython Motorized Camera Slider](https://learn.adafruit.com/circuitpython-motorized-camera-slider.md)