Creating Functions

Read this for more on functions.

Chapter 3 Functions

3.13 Glossary


A named sequence of statements that performs some useful operation. Functions may or may not take arguments and may or may not produce a result.

function definition:

A statement that creates a new function, specifying its name, parameters, and the statements it contains.

function object:

A value created by a function definition. The name of the function is a variable that refers to a function object.


The first line of a function definition.


The sequence of statements inside a function definition.


A name used inside a function to refer to the value passed as an argument.

function call:

A statement that runs a function. It consists of the function name followed by an argument list in parentheses.


A value provided to a function when the function is called. This value is assigned to the corresponding parameter in the function.

local variable:

A variable defined inside a function. A local variable can only be used inside its function.

return value:

The result of a function. If a function call is used as an expression, the return value is the value of the expression.

fruitful function:

A function that returns a value.

void function:

A function that always returns None.


A special value returned by void functions.


A file that contains a collection of related functions and other definitions.

import statement:

A statement that reads a module file and creates a module object.

module object:

A value created by an import statement that provides access to the values defined in a module.

dot notation:

The syntax for calling a function in another module by specifying the module name followed by a dot (period) and the function name.


Using an expression as part of a larger expression, or a statement as part of a larger statement.

flow of execution:

The order statements run in.

stack diagram:

A graphical representation of a stack of functions, their variables, and the values they refer to.


A box in a stack diagram that represents a function call. It contains the local variables and parameters of the function.


A list of the functions that are executing, printed when an exception occurs.