Identifying and Correcting Errors
Practice with identifying and correcting code blocks
alphabet = "abcdefghijklmnopqrstuvwxyz"
alphabetList = []
for i in alphabet:
alphabetList.append(i)
print(alphabetList)
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 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?")
count = 0
for i in alphabetList:
if i == letter:
print("The letter " + letter + " is the " + str(count + 1) + " letter in the alphabet")
count += 1
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 = 0
while i <= 10:
evens.append(i)
i += 2
print(evens)
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)
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)
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)
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 = 1
while i < 100:
numbers.append(i)
i += 1
for i in numbers:
if numbers[i-1] % 5 == 0:
newNumbers.append(numbers[i-1])
elif numbers[i-1] % 2 == 0:
newNumbers.append(numbers[i-1])
print(newNumbers)
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,
"salad": 2.99}
subtotal = 0
items = 0
print("<><><><><><><><><><><><><><>")
#shows the user the menu and prompts them to select an item
print("Hello! Here is our menu:")
for k,v in menu.items():
print(k + " $" + str(v)) #why does v have "str" in front of it?
print("<><><><><><><><><><><><><><>\n")
#ideally the code should prompt the user multiple times
# item = input("Please select an item from the menu. ")
print("Your Order:\n")
while items != "done":
items = input("Enter the items you want to order here. Press [enter] after every item. Type 'done' when you have selected everything you want to order. ")
if items == "done":
print("")
print("Thank you for ordering!")
elif items == "burger" or items == "fries" or items == "drink" or items == "salad":
print(items)
subtotal += menu[items]
else:
print(items + " is not an item listed on the menu. Please enter a valid item.")
subtotal = round(subtotal, 2)
total = round(subtotal * 0.0775 + subtotal, 2)
#code should add the price of the menu items selected by the user
print("")
print("Subtotal: $" + str(subtotal))
print("Tax: 7.75%")
print("Total: $" + str(total))
Hacks
Now is a good time to think about Testing of your teams final project...
- What errors may arise in your project?
- What are some test cases that can be used?
- Make sure to document any bugs you encounter and how you solved the problem.
- What are “single” tests that you will perform on your project? Or, your part of the project?
- As Hack Design and Test plan action … Divide these “single” tests into Issues for Scrum Board prior to coding. FYI, related tests could be in same Issue by using markdown checkboxes to separate tests.