1.3. WHIRLWIND INTRODUCTION TO TYPES AND FUNCTIONS 11

Look at the Python Shell. ...
In the Shell the last line should look like
>>>
The >>> is the prompt, telling you Idle is waiting for you to type something. Continuing on the same line
enter
6+3
Be sure to end with the Enter key. After the Shell responds, you should see something like
>>> 6+3
9
>>>
The shell evaluates the line you entered, and prints the result. You see Python does arithmetic. At the
end you see a further prompt >>> where you can enter your next line.... The result line, showing 9, that is
produced by the computer, does not start with “>>>”.
1.3. Whirlwind Introduction To Types and Functions
Python directly recognizes a variety of types of data. Here are a few:
Numbers: 3, 6, -7, 1.25
Character strings: ’hello’, ’The answer is: ’
Lists of objects of any type: [1, 2, 3, 4], [’yes’, ’no’, ’maybe’]
A special datum meaning nothing: None
Python has large collection of built-in functions that operate on different kinds of data to produce all kinds
of results. To make a function do its action, parentheses are required. These parentheses surround the
parameter or parameters, as in a function in algebra class.
The general syntax to execute a function is
functionName ( parameters )
One function is called type, and it returns the type of any object. The Python Shell will evaluate functions.
In the Shell the last line should look like
>>>
Continuing on the same line enter