For example, we may create a dictionary containing the data of a rigid body in mechanics, as follows:
truck_wheel = {'name':'wheel','mass':5.7, 'Ix':20.0,'Iy':1.,'Iz':17., 'center of mass':[0.,0.,0.]}
A key/data pair is indicated by a colon, :. These pairs are comma-separated and listed inside a pair of curly brackets, {}.
Individual elements are accessed by their keys:
truck_wheel['name'] # returns 'wheel' truck_wheel['mass'] # returns 5.7
New objects are added to the dictionary by creating a new key:
truck_wheel['Ixy'] = 0.0
Dictionaries are also used to provide parameters to a function (refer to Section 7.2: Parameters and arguments in Chapter 7, Functions, for further information).
Keys in a dictionary can be, among others...