Day 013

Udemy Python Bootcamp Day 013

Debugging

Describe Problem

def my_function():
  for i in range(1, 20):
  #it actually goes from 1 all the way up to 19 but not including 20
    if i == 20:
      print("You got it")
my_function()

# Solution
def my_function():
  for i in range(1, 21): 
    if i == 20:
      print("You got it")
my_function()

Reproduce the Bug

from random import randint
dice_imgs = ["❶", "❷", "❸", "❹", "❺", "❻"]
dice_num = randint(1, 6)
# randint(a, b) : Return random integer in range [a, b], including both end points.
print(dice_imgs[dice_num])

# Solution
from random import randint
dice_imgs = ["❶", "❷", "❸", "❹", "❺", "❻"]
dice_num = randint(0, 5)
print(dice_imgs[dice_num])

Play Computer

year = int(input("What's your year of birth?"))
if year > 1980 and year < 1994:
  print("You are a millenial.")
elif year > 1994:
  #When input'1994', print noting
  print("You are a Gen Z.")
  
# Solution
 year = int(input("What's your year of birth?"))
if year > 1980 and year < 1994:
  print("You are a millenial.")
elif year >= 1994:
  print("You are a Gen Z.")

Fix the Errors

age = input("How old are you?")
# we're getting the input from the console as a string, so we must that input string to an integer object in order to do numerical operations.
if age > 18:
print("You can drive at age {age}.")
#indent error & f-string

# Solution
age = int(input("How old are you?"))
if age > 18:
  print(f"You can drive at age {age}.")

Print is Your Friend

pages = 0
word_per_page = 0
pages = int(input("Number of pages: "))
word_per_page == int(input("Number of words per page: "))
# two equal sigh gets evaluated and becomes either true or false.
total_words = pages * word_per_page
print(total_words)

# Solution
pages = 0
word_per_page = 0
pages = int(input("Number of pages: "))
word_per_page = int(input("Number of words per page: "))
total_words = pages * word_per_page
print(total_words)

Use a Debugger

def mutate(a_list):
  b_list = []
  for item in a_list:
    new_item = item * 2
  b_list.append(new_item)
  # to fix this code is just to indent that line over.
  print(b_list)

mutate([1,2,3,5,8,13])
#output
[26]

# Solution
def mutate(a_list):
  b_list = []
  for item in a_list:
    new_item = item * 2
    b_list.append(new_item)
  print(b_list)

mutate([1,2,3,5,8,13])
#output
[2, 4, 6, 10, 16, 26]

Final debugging tips

• TAKE A BREAK!
• ASK A FRIEND!
• run often..
• ASK StackOverflow
  
  

exercise1

number = int(input("Which number do you want to check?"))

if number % 2 = 0:
  print("This is an even number.")
else:
  print("This is an odd number.")

# Solution
number = int(input("Which number do you want to check?"))

if number % 2 == 0:
  print("This is an even number.")
else:
  print("This is an odd number.")

exercise2

year = input("Which year do you want to check?")

if year % 4 == 0:
  if year % 100 == 0:
    if year % 400 == 0:
      print("Leap year.")
    else:
      print("Not leap year.")
  else:
    print("Leap year.")
else:
  print("Not leap year.")

# Solution
year = int(input("Which year do you want to check?"))

if year % 4 == 0:
  if year % 100 == 0:
    if year % 400 == 0:
      print("Leap year.")
    else:
      print("Not leap year.")
  else:
    print("Leap year.")
else:
  print("Not leap year.")

exercise3

for number in range(1, 101):
  if number % 3 == 0 or number % 5 == 0:
    print("FizzBuzz")
  if number % 3 == 0:
    print("Fizz")
  if number % 5 == 0:
    print("Buzz")
  else:
    print([number])

# Solution
for number in range(1, 101):
  if number % 3 == 0 and number % 5 == 0:
    print("FizzBuzz")
  elif number % 3 == 0:
    print("Fizz")
  elif number % 5 == 0:
    print("Buzz")
  else:
    print(number)