In Chapter 3, Using Python as a Financial Calculator, tuples are introduced as one of the data types. Recall that a tuple is defined by using parentheses such as x=(1,2,3,"Hello"). In addition, after a tuple is defined, we cannot change its values. Like tuples, the lists data type could contain different types of data, and their first subscripts start from 0. The following Python commands generate a list for variable x:

>>>x=[1,2,"John", "M", "Student"]
>>>type(x)
<class 'list'>

From the preceding code statements, we know that a set of variables included will be closed by a pair of square brackets, that is []. To call specific data item(s), we could use different ways to achieve our goals. The following commands show how to pick up individual data items for different goals:

>>>x
[1, 2, 'John', 'M', 'Student']
>>>x[1]
2
>>>x[2:]
['John', 'M', 'Student']

Unlike tuples, we can modify the values of a list.