Functions

Question 1

Explain calling a function and what a function call is

Answer 1

• Using function = calling
• Line of code that uses function = function call

Question 1

What is a function?

Answer 1

• Code that you’ve given a name to (such as print, str, iter, or next).
• Accomplish a task.
• When you use that function name in a program, execution of the code jumps to that function block, executes the function, and then returns to the point where the function name was called

Question 2

How to define and call a simple function? Give example

Answer 2

def my_first_function():
    print("Hello you")

my_first_function()

Question 3

Define Scope

Answer 3

• Scope refers to the definition of variables or functions in Python and the accessibility in different parts of program .
• Applies to variables and functions

**Local Scope: **
Variables created within a function and accessible only inside that function.

Global Scope:
Variables defined outside any function, accessible anywhere in the code.

Question 4

What scope rule exists with variables created in functions?

Answer 4

If a variable was created in a function, it only exists in that function

Question 5

What happens when you define my_variable inside and outside a function and both Variables have the same name

Answer 5

• Because the variable within the function only exists within the function, to the rest of the program it is as if that variable does not exist.
• That’s why when we change the value of that variable, it does not change the value of the variable outside of the function.
• The interpreter actually creates two variables with the same name, one within the function and one outside of the function. Changing the value of one will not affect the other.

Question 6

What is a nested function?

Answer 6

• Function defined within another function.
• Scope of parent function

Question 7

What is a global Variable and how to access it within functions. Demonstrate.

Answer 7

You use the global keyword to preface the variable you’re going to use. This will tell the interpreter that you want to use the global version of that variable instead of creating a new local version

x = 1
def my_function()
    global x
    x = 10
    print(x)

my_function()
print(x)

Question 8

What is a nonlocal variable?

Answer 8

• Access a function’s local variable from a nested function within that function.
• nonlocal keyword.
• Tells interpreter that you want to use the version created in the parent function

Question 9

What are Arguments?

Answer 9

Values that are passed into functions via parameters

Question 10

Where are function parameters defined?

Answer 10

Between open and closed parentheses is the function definition
Each parameter is seperated by a comma

Question 11

Define an example of a simple function with parameters

Answer 11

def add_num(a, b, c)
    the_sum = a + b + c
    print(the_sum)
    
add_num(1, 5, 6)

Question 12

Can you think of an important rule for arguments passed into function?

Answer 12

Number of arguments passed into function must be equal to number of arguments specified in function definition

Question 13

What are the two types of argument setups. Give example

Answer 13

Positional arguments
Correct position is crucial
~~~
add_num(1, 5, 6)
~~~

Named arguments
Order of arguments not important, naming is important
add_num(b=4, c=100, a=1)

Question 14

What are default arguments?

Answer 14

• You can specify a default value for an argument in a function definition, and if that argument is not passed in during the function call, the argument will assume the default value.
• If the argument is passed in during the function call, the passed in value overrides the default value.
• You specify a default value for an argument by setting it equal to a value in the function definition

Question 15

Define a default argument

Answer 15

def add_fun(a, b=5, c=3)
    sum = (a + b + c)
    print(sum)
    
add_fun(1)

Result:
9

Question 16

Which important rule is there with default arguments?

Answer 16

All default arguments have to be on the right-hand side of the function’s argument list

Question 17

What are return values?

Answer 17

• Returns values form function

A return statement simply uses the keyword “return” followed by a value or set of values that you want to return to the program at the point you called the function.

One thing to note: the return statement will exit your function, so make sure you do not have code that you want to run placed inside your function after your return statement—that code will never be executed!

Question 18

If a function returns multiple values which data type will be returned? Give example

Answer 18

def math(a, b)
    add = a + b
    sub = a - b
    return add, sub
print(math(6, 2)

Result
(8, 4)