Skip to main content
Library homepage
 
Engineering LibreTexts

8.1: A list is a sequence

  • Page ID
    8618
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    Like a string, a list is a sequence of values. In a string, the values are characters; in a list, they can be any type. The values in list are called elements or sometimes items.

    There are several ways to create a new list; the simplest is to enclose the elements in square brackets ([ and ]):

    [10, 20, 30, 40]
    ['crunchy frog', 'ram bladder', 'lark vomit']

    The first example is a list of four integers. The second is a list of three strings. The elements of a list don't have to be the same type. The following list contains a string, a float, an integer, and (lo!) another list:

    ['spam', 2.0, 5, [10, 20]]

    A list within another list is nested.

    A list that contains no elements is called an empty list; you can create one with empty brackets, [].

    As you might expect, you can assign list values to variables:

    >>> cheeses = ['Cheddar', 'Edam', 'Gouda']
    >>> numbers = [17, 123]
    >>> empty = []
    >>> print(cheeses, numbers, empty)
    ['Cheddar', 'Edam', 'Gouda'] [17, 123] []

    This page titled 8.1: A list is a sequence is shared under a CC BY-NC-SA license and was authored, remixed, and/or curated by Chuck Severance.

    • Was this article helpful?