Guess the Number¶

In this chapter you will:¶

area	topic
🚀	write a number guessing game
💡	use the string data type
⚙	implement a conditional loop
🔧	enter Python commands
🐞	debug endless loops

Exercise 1: Conditional Loops¶

In this chapter, you will need a new command to influence the order in which instructions are executed: the conditional loop or while loop.

Match the expressions so that the while loops run the designated number of times.

Exercise 2¶

Which of these while commands are correct?

while a = 1:

while b == 1

while a + 7:

while len(c) > 10:

while a and (b-2 == c):

while s.find('c') >= 0:

Exercise 3¶

Which statements are correct?

while is also called a conditional loop
The expression after while may contain function calls
It is possible to while loops that run forever
The colon after while may be omitted
The code block after while is executed at least once

Exercise 4: Search¶

The following for loop searches for 33 in the data. Modify the code, so that it uses a while loop instead.

data = [5, 7, 33, 12, 4, 3, 18]

found = False
for n in data:
    if n == 33:
        found = True

print("The value 33 has been found: {}".format(found))

Exercise 5¶

The following while loop counts numbers higher than 10. Change the code so that it uses a for loop instead.

data = [4, 7, 11, 1, 3,  15]

i = 0
high = 0
while i < len(data):
    if data[i] > 10:
        high += 1
    i += 1

print(f"There are {high} values higher than 10")

Exercise 6¶

Which of the following while loops will finish?

Exercise 6.1¶

count = 0
while count > 0:
    print count
    count += 1

Exercise 6.2¶

text = "a"
while "z" not in text:
    text += "a"

Exercise 6.3¶

a = 7
b = 135
while a != b:
    a += (a - b) / 10.0
    b -= (a - b) / 10.0

Exercise 6.4¶

n = 0
while n * 5 != n ** 2:
    n += 2

Exercise 6.5¶

data = [1, 2, 7, 8]
while data[-1] > 2:
    data.pop()

Exercise 6.6¶

data = [2, 3, 15]
while data[0] < 100:
    data = data[1:]

Exercise 7: Implement the game¶

In the Guess the Number game, the player tries to guess a number that the computer has generated.

The program randomly “rolls” a number between 1 and 100.
Do not output the number.
The player enters a number.
The program says whether the number was too big or too small.
Repeat steps 3-5 until the correct number was guessed.

Example output:¶

I have memorized a number.
Try to guess it!

Please enter a number (1-100): 33
My number is lower.

Please enter a number (1-100): 22
My number is lower.

Please enter a number (1-100): 11
My number is higher.

Please enter a number (1-100): 17
My number is lower.

Please enter a number (1-100): 14
My number is lower.

Please enter a number (1-100): 13
You found it!