Local and global variables

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. A variable is created inside a function. Where can it be used?

A Only inside that function

B Anywhere in the program

2. Which program causes a NameError?

A def game(): score = 5 game() print(score)

B score = 5 def game(): print(score) game()

3. Which variable is a global variable?

A name = "Sam" written outside all functions

B name = "Sam" written inside def greet():

4. True or false: a local variable still exists after its function has finished running.

A True

B False

5. A function needs to use a value from outside it. What is a good way to give it that value?

A Hope Python finds the local variable from another function

B Pass it in as a parameter, like def show(points):

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1def show(): score = 5 print(score)		Aname is a global variable, made outside all functions, so greet() can use it
2name = "Sam" def greet(): print(name)		Bdef double(num): print(num * 2)
3A variable created inside a function is local and only exists while that function runs		CNameError: score is a local variable made inside show(), so it does not exist outside the function
4Use a parameter to pass a value into a function so it does not need to use a variable from outside		Ddef add(): total = 2 + 3
5def make(): age = 12 make() print(age)		Eage is local to make(), so print(age) outside the function causes a NameError. Fix: print it inside the function or return it.
6def show(): print(points) show()		Fpoints was never created, so show() causes a NameError. Fix: create points outside the function first or pass it in as a parameter.

Definitions

local variable

Fill in the Blanks

Complete each line of code by filling in the missing parts.

def show(): total = 5 print(_____)

___ add_bonus(): bonus = 10 print(bonus)

score = 0 def show(): print(_____)

def double(___): print(num * 2) double(4)

def make(): x = 3 ______ x

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A def show():

B score == 10

C print(score)

D show()

Question 2

A def double(n):

B result = x * 2

C return result

D print(double(5))

Question 3

A lives = 3

B def show():

C print(live)

D show()

Question 4

A def make():

B x = 7

C print(y)

D make()

Question 5

A def hello(name):

B print("Hi", Name)

C hello("Mia")

Answer Key

Local and global variables

Section A: Quick Questions

A — Only inside that function

A — def game(): score = 5 game() print(score)

A — name = "Sam" written outside all functions

B — False

B — Pass it in as a parameter, like def show(points):

Section B: Match the Pairs

def show(): score = 5 print(score) → NameError: score is a local variable made inside show(), so it does not exist outside the function

name = "Sam" def greet(): print(name) → name is a global variable, made outside all functions, so greet() can use it

A variable created inside a function is local and only exists while that function runs → def add(): total = 2 + 3

Use a parameter to pass a value into a function so it does not need to use a variable from outside → def double(num): print(num * 2)

def make(): age = 12 make() print(age) → age is local to make(), so print(age) outside the function causes a NameError. Fix: print it inside the function or return it.

def show(): print(points) show() → points was never created, so show() causes a NameError. Fix: create points outside the function first or pass it in as a parameter.

Section C: Definitions

local variable — A variable created inside a function. It only exists in that function, so using it outside gives a NameError. A variable made outside all functions is global and can be used anywhere.

Section D: Fill in the Blanks

def show():
    total = 5
    print(total)

def add_bonus():
    bonus = 10
    print(bonus)

score = 0
def show():
    print(score)

def double(num):
    print(num * 2)
double(4)

def make():
    x = 3
    return x

Section E: Spot the Error

B — A single = is needed to create the local variable. With ==, score is never created, so print(score) gives a NameError. It should be score = 10.

B — x is not a parameter or a variable made in this function, so Python gives a NameError. The function should use the parameter n: result = n * 2.

C — The global variable is called lives, but live was typed. That name does not exist, so there is a NameError. It should be print(lives).

C — The only local variable made in make() is x. The name y was never created, so Python gives a NameError. It should be print(x).

B — Python is case sensitive. The parameter is name, not Name, so Name causes a NameError. It should be print("Hi", name).