Lists

Lists are a way Python can store multiple pieces of data. For instance the abbreviated days of the week:

['M','T','W','R','F','S','S']

['M', 'T', 'W', 'R', 'F', 'S', 'S']

We can make lists of numbers and even us numbers from an imported math module to add some interesting numbers.

import math as math

math.pi

3.141592653589793

[math.pi,0,-1,math.e]

[3.141592653589793, 0, -1, 2.718281828459045]

List Comprehension

Operations or functions can be performed on members of a list using a powerful technique know as list comprehension, study these examples:

list = [0, 1, 2, 3, 4]
list

[0, 1, 2, 3, 4]

[2*x for x in list]

[0, 2, 4, 6, 8]

[2**x for x in list]

[1, 2, 4, 8, 16]

The x in these examples is a placeholder which iterates through the values in the list and communicates these vales to the operation (i.e 2**x) to create the new list. We can use any other label here such as temp.

Example

An ideal gas is the simplest description of the way gas molecules and atoms interact and the relationship between temperature, volume, pressure, and number of molecules. See:Open Stax

P V = n R T

P = pressure in atm
V = volume in liter
n = number of moles
R = gas constant = 0.082057 L atm / mol K
T = temperature in Kelvin

Challenge: Compute the volume of 1 mole of gas at 1 atm and the follwing temperatures T = 298 K (room remperature), 310 K, 273 K

T = [273, 298, 310]

P = 1.0
n = 1.0
R = 0.082057

• Use a list to compute volume at the 3 temperatures

V = [n*R*temp/P for temp in T]

V

[22.401561, 24.452986000000003, 25.43767]