Exercises
Contents
Exercises¶
If you ever get really stuck on an exercise, skip it and ask for help!
Exercise 1 - Variables¶
a) What is a variable? Why do you think they are called variables?
A variable is a storage adress associated with a variable name. Some value is stored at the adress. They might be called variables because their values can vary during the execution of a program.
b) Define two integers and print their sum.
a = 50
b = 21414
print(a + b)
21464
c) Define two strings, add them together (+), and print the result.
first = "Bob"
last = " Ross"
print(first + last)
Bob Ross
d) Let a, b and c be declared like in the code below. Use a fourth variable to swap the values of a and b, and then b and c.
a = 1
b = 2
c = 3
temp = a
a = b
b = temp
temp = b
b = c
c = temp
e) What will this code output?
a = 3
b = a
a = 5
print(b)
It will output 3, as b was defined to be the value of a when a was 3.
f) What is the difference between 3, 3.0, '3', '''3''' and "3"?
In order, their type is: integer, float, string, string, string.
g) What variable type should be used to store:
Whether Wednesday’s weather will water wallflowers
The number Wednesdays on which it has rained before
The probability of it raining on Wednesday
A description of Wednesday’s weather
Whether Wednesday’s weather will water wallflowers - boolean
The number Wednesdays on which it has rained before - integer
The probability of it raining on Wednesday - float
A description of Wednesday’s weather - string
h) What happens when you try to print the following:
1/0variableName(40)"Ola" + 5"Ola", 5
1/0- You will get a zero division errorvariableName(40)- You will get an error as you are trying to call a function which is undefined. Or if variableName is a defined variable, you will get an error from trying to call a variable as a function."Ola" + 5- You will get an error as you cannot add together strings and integer"Ola", 5- You will print “Ola 5”
Exercise 2 - Decisions¶
a) Write a program that prints whether a number is larger than 10.
number = 10
if number > 10:
print("The number is larger than 10")
else:
print("The number is not larger than 10")
The number is not larger than 10
b) Write a program that declares two integers, smallest and largest. Make it so that if smallest is the largest number, the values are swapped.
smallest = 40
largest = 12
if largest < smallest:
temp = smallest
smallest = largest
largest = temp
c) Write a program that grants any loan under 1 million to anyone between the ages of 18 and 80.
age = 33
loanAmount = 999999
if age > 18 and age < 80:
if loanAmount < 1000000:
print("Yes")
else:
print("No")
else:
print("No")
Yes
d) Write a program that grants a loan randomly, with different probabilites depending on some factor like gender, age or loan amount. (using randint())
from random import randint
age = 33
loanAmount = 999999
if age > 33: #50% of people older than 33 are given loans under 100k
if randint(1, 2) == 1 and loanAmount < 100000:
print("Yes")
else:
print("No")
else: #20% of people 33 or under are given loans under 100k
if randint(1, 5) == 1 and loanAmount < 100000:
print("Yes")
else:
print("No")
No
Exercise 3 - Random number generation¶
a) Write a program that prints a random whole number from 0 to 50.
num = randint(0, 50)
print(num)
34
b) Write a program that prints a random even number from 0 to 100.
evenNum = randint(0, 50) * 2
print(evenNum)
54
c) Write a program that prints out “Heads” 49% of the time, “Tails” 49% of the time, and “Standing” 2% of the time.
result = randint(1,100)
if result <= 49: #1 to 49 is 49%
print("Heads")
elif result <= 98: #50 to 98 is 49%
print("Tails")
else: #99 and 100 is 2%
print("Standing")
Standing
d) Write a program that generates 5 random coin tosses (50% heads, 50% tails), and prints out the total number of heads.
heads = 0
heads = heads + randint(0,1)
heads = heads + randint(0,1)
heads = heads + randint(0,1)
heads = heads + randint(0,1)
heads = heads + randint(0,1)
print("The total number of heads is", heads)
The total number of heads is 5
e) Write a program that throws an error 50% of the time.
coin = randint(0,1)
if coin == 0:
print(1/0)
else:
print("Phew!")
Phew!