# Python Reading

## Key Ideas

- NumPy is Python library written in C to provide fast numerical
methods for scientific computation.
- NumPy enables Python users to use a data structure
called an array. You can conceptualize an array as an
efficient implementation of a list.
- Today we will learn about 1-D (one dimensional) arrays.
However, Python arrays can contain any number of dimensions.

## Getting Started

- Install NumPy on your machine:
- Windows:
**python -m pip install numpy**
- Mac:
**pip3 install --user numpy**

## In-Class Activity

- One way to gain insight into numeric data is to calculate
its mean and standard deviation. More information.
- Sometimes it is useful to sort numeric data into either
ascending or descending order. Why?
- Download demo.py and
conduct experiments until you fully understand it.
- Can you explain how the sort function works?
- The sort function does not return anything.
Why does the shoulder_heights array in the main program change?
- Can you modify the sort function so that it sorts the
data into descending order?
- The NumPy module includes a sort function. Can you find
the relevant documentation and then use it?
- What are other useful things you might want to do with
a 1-D array?

## Active Learning

### Optional Alternative NumPy Installation for Windows Users

Enter the second instruction in the MS-DOS command prompt,
from the same directory where the module was downloaded.

- Download numpy, choosing the version in the next instruction.
- python -m pip install numpy-1.13.3+mkl-cp36-cp36m-win32.whl