Part 5

Question 1

What does the scope of a variable denote?

Answer 1

The area of the program from which it is accessible

Question 2

If given a value outside of a function, what scope does a variable have?

Answer 2

Global - accessible from elsewhere in program

Question 3

What is global scope?

Answer 3

Means variable can be accessed from anywhere in the program

However - cannot create a new variable with the same name even in a seperate function

Question 4

What is local scope?

Answer 4

Variable only accessible from within the function it was defined in.

Question 5

What Exception type is raised when a variable that does not exist is accessed?

Answer 5

NameError: name ‘variablename’ is not defined

Happens also when variablename has local scope but is attempted to be accessed outside of the function

Question 6

What happens when you try to set the value of a global variable inside a function?

What would happen if you executed this:

def myfun():

print(x)

x = 5

x = 10

myfun()

Answer 6

It masks the global variable - so any changes within the function will not affect the global variable

The program shown would raise an UnboundLocalError - trying to access the variable before it is assigned

Question 7

What is the lifetime of a variable?

Answer 7

The time it will remain in existence in a program

Global variables exist for the entire duration of the program after being assigned

Local variables only for the duration of their function

Question 8

What happens when a mutable object is passed as an argument to a function, then modified within the function?

Answer 8

The original object is actually modified. Probably because they are pointers to the objects rather than copies of

Question 9

May tuples contain multiple types?

Answer 9

Yes.

Question 10

How can we create a tuple with just one element?

Answer 10

mytup = (1,)

Will contain just the element 1