Читать книгу Algorithms For Dummies - John Paul Mueller, John Mueller Paul, Luca Massaron - Страница 82

To perform useful work with Python, you often need to work with larger amounts of data that come in specific forms. These forms have odd-sounding names, but the names are quite important. The three terms you need to know for this chapter are as follows:

 Scalar: A single base data item. For example, the number 2 shown by itself is a scalar.

 Vector: A one-dimensional array (essentially a list) of data items. For example, an array containing the numbers 2, 3, 4, and 5 would be a vector.

 Matrix: A two-or-more-dimensional array (essentially a table) of data items. For example, an array containing the numbers 2, 3, 4, and 5 in the first row and 6, 7, 8, and 9 in the second row is a matrix.

Python provides an interesting assortment of features on its own, but you'd still need to do a lot of work to perform some tasks. To reduce the amount of work you do, you can rely on code written by other people and found in packages. The following sections describe how to use the NumPy package (https://numpy.org/) to perform various tasks on scalars, vectors, and matrixes. This chapter provides an overview of NumPy by emphasizing the features you use later (see https://www.w3schools.com/python/numpy/default.asp for more details).