Identifying and Correcting Errors (Unit 1.4)

Become familiar with types of errors and strategies to fixing them

Lightly Review Videos and take notes on topics with Blog

Complete assigned MCQ questions

Here are some code segments you can practice fixing:

alphabet = "abcdefghijklmnopqrstuvwxyz"

alphabetList = []

for i in alphabet:
    alphabetList.append(i)

print(alphabetList)

['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']

The intended outcome is to determine where the letter is in the alphabet using a while loop

What is a good test case to check the current outcome? Why?
Make changes to get the intended outcome.

letter = input("What letter would you like to check?")

i = 0

while i < 26:
    if alphabetList[i] == letter:
        print("The letter " + letter + " is the " + str(i + 1) + " letter in the alphabet")
    i += 1

The letter a is the 1 letter in the alphabet

The intended outcome is to determine where the letter is in the alphabet using a for loop

What is a good test case to check the current outcome? Why?
Make changes to get the intended outcome.

letter = input("What letter would you like to check?")

for i in alphabetList:
    count = 0
    if i == letter:
        print("The letter " + letter + " is the " + str(count + 1) + " letter in the alphabet")
    count += 1

The letter a is the 1 letter in the alphabet

This code outputs the even numbers from 0 - 10 using a while loop.

Analyze this code to determine what can be changed to get the outcome to be odd numbers. (Code block below)

evens = []
i = 2

while i <= 10:
    evens.append(i)
    i += 2

print(evens)

[2, 4, 6, 8, 10]

This code should output the odd numbers from 0 - 10 using a while loop.

odds = []
i = 1

while i <= 10:
    odds.append(i)
    i += 2

print(odds)

[1, 3, 5, 7, 9]

This code outputs the even numbers from 0 - 10 using a for loop.

Analyze this code to determine what can be changed to get the outcome to be odd numbers. (Code block below)

numbers = [0,1,2,3,4,5,6,7,8,9,10]
evens = []

for i in numbers:
    if (numbers[i] % 2 == 0):
        evens.append(numbers[i])

print(evens)

[0, 2, 4, 6, 8, 10]

This code should output the odd numbers from 0 - 10 using a for loop.

numbers = [0,1,2,3,4,5,6,7,8,9,10]
odds = []

for i in numbers:
    if (numbers[i] % 2 == 1):
        odds.append(numbers[i])

print(odds)

[1, 3, 5, 7, 9]

The intended outcome is printing a number between 1 and 100 once, if it is a multiple of 2 or 5

What values are outputted incorrectly. Why?
Make changes to get the intended outcome.

numbers = []
newNumbers = []
i = 0

while i <= 100:
    numbers.append(i)
    i += 1

for i in numbers:
    if numbers[i] == 0:
        pass
    elif numbers[i] % 5 == 0 or numbers[i] % 2 == 0:
        newNumbers.append(numbers[i])

print(newNumbers)

[2, 4, 5, 6, 8, 10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28, 30, 32, 34, 35, 36, 38, 40, 42, 44, 45, 46, 48, 50, 52, 54, 55, 56, 58, 60, 62, 64, 65, 66, 68, 70, 72, 74, 75, 76, 78, 80, 82, 84, 85, 86, 88, 90, 92, 94, 95, 96, 98, 100]

Challenge

This code segment is at a very early stage of implementation.

What are some ways to (user) error proof this code?
The code should be able to calculate the cost of the meal of the user

Hint:

write a “single” test describing an expectation of the program of the program
test - input burger, expect output of burger price
run the test, which should fail because the program lacks that feature
write “just enough” code, the simplest possible, to make the test pass

Then repeat this process until you get program working like you want it to work.

menu =  {"burger": 3.99,
         "fries": 1.99,
         "drink": 0.99}
total = 0
ordering = True

#shows the user the menu and prompts them to select an item
print("Menu")
for k,v in menu.items():
    print(k + "  $" + str(v)) #why does v have "str" in front of it?

while ordering == True:
    item = input("Please select an item from the menu or select 'done'")
    print(item)
    if item == "done": # checks if you are done with your order
        ordering = False
    elif item in menu: # checks if key exists in menu dictionary
        total += menu[item] # find any item from the dictionary and add its value to total
    else:
        print("input incorrect, please try again") # if you misspelled a word then you can re-enter the word

#code should add the price of the menu items selected by the user 
print("your total: $" + str(total))

Menu
burger  $3.99
fries  $1.99
drink  $0.99
foot lettuce
input incorrect, please try again
burger
drink
done
your total: $4.98

Bugs/Errors

If you misspelled a word the program would encounter an error, I fixed this by adding an "else" statement that allows you to re-enter your order, I also had to google how to check if a key is in your dictionary to check if the key is correct.
For some reason if you order a burger fries and a drink you get charged $6.970000000000001 ## "single" tests
"single" tests on my own project I can isolate specific parts of my program and use print statements to isolate specific problems