Section 14: Arguments and FUnction Objects

Question 1

Review

What are the different parts of a function called

Answer 1

Question 2

Positional, Keywork, Display

What is the difference between a Positional Argument and a Keyword Argument?

Answer 2

```python
def display_square(x, message):
print(message, x*x)
~~~

(1) Positional Arguments must be the same order as parameters:

Call function:
display_square(5, 'Square of 5')

(2) Keyword Arguments are “wordy” but can be in different order:

Call Function: display_square(message = 'Square of 5', x = 5)

Question 3

Positional, Keywork, Default

What are default values?

Answer 3

(3) Default Value used when the argument is missing from the call

• If the call the function without providing a value for the message, its default value will be used:

```python
def display_square(x, message = “The solution is”):
#Message arugment is default equal to ‘The solution is’
#If the function is called without an argument, default is used

print(message, x*x)

> > > display_square(5)
The soluation is 25
~~~

Question 4

What happens when a function defintiion is called?

Answer 4

When a function definition is executed:

1. An object created that stores the code of the function
2. Reference to this object is stored in variable named after the function

Question 5

How are functions “callable?”

Answer 5

Function objects are callable, they can use the invocation operator () to execute the code

Note: Difference between …

• my_function: a variable references a function object
• my_fuction(1, 2): a call to the function object, evaluates whatever it returns

Question 6

How can functions be used as variables?

Note: Difference between …

• my_function: a variable references a function object
• my_fuction(1, 2): a call to the function object, evaluates whatever it returns

Answer 6

Functions as variables: can be assigned to another variable

Question 7

How can functions be used as arguments?

Note: Difference between …

• my_function: a variable references a function object
• my_fuction(1, 2): a call to the function object, evaluates whatever it returns

Answer 7

Functions as arguments: can be passed as arguments to another function

Question 8

How can functions be a return type?

Answer 8

Functions as return types: can be returned from a function