Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Python Introduction to NumPy Meet NumPy Introducing Arrays

Array-building starts at 4:14. For those of us who watch first and then go back to go through the steps.

Array building

1 Answer

Yes that's correct, the first four minutes go over some crucial notes about what's going on under the hood, with the computer's memory allocation in NumPy, and what its benefits are. Here are the notes of @craigsdennis:

## Differences between lists and NumPy Arrays
* An array's size is immutable.  You cannot append, insert or remove elements, like you can with a list.
* All of an array's elements must be of the same [data type](https://docs.scipy.org/doc/numpy-1.14.0/user/basics.types.html).
* A NumPy array behaves in a Pythonic fashion.  You can `len(my_array)` just like you would assume.