Authentication

• You may see this chunk of red text when an error occurs

  
• This chunk of red text when an error occurs is helpful as it tells us the exact line of the error and its type

  
• Using the image below, what line has the error occurred in?

  Line 10

  
• Using the image below, what type of error has occurred?

  NameError

  
• Exception Handling is where a complete program should have a code in place for when an unexpected error occurs
• In this example, Python will attempt to run the code indented beneath "try:" - If there are no errors , the code will stop just before "except" - If an error does occur, the exception code will be run

  
• In the code below, if we enter a correct value , the program will execute normally

  
• In the code below, if an error occurs, the exception code will run - e.g. if you enter the string "cheese" , than the code will run and say "You did not enter a number"

  
• You can add the else command to your code - It will only execute if there are no errors

  
• If a valid number is entered into this code, the else code will be printed (e.g. if time == 4, "How many days will you be with us" "Oh 4 days? I'll fetch your bags!")

  
• If a code generating an error is entered , the except code will be printed (e.g. if time = umbrella, "How many days will you be with us" "Sorry, I don't understand? GET OUT MY HOTEL!")

  
• The code below asks the user to their age in years as a number - If a valid number is generated , the else code is printed - If a code generating an error is used, the exception code will be printed

  
• The exception command can be used for any general error that occurs
• Specific exception commands can be used for a variety of errors
• In the program below, how many specific exception commands are there?

  2

  
• In the code below, if the wrong data type is entered, a Value Error occurs , and this prints the relevant response

  
• In the code below, if the user tries to divide by 0, a Zero Division Error occurs, and this prints the relevant response

  
• In the code below, what response will be printed if a ValueError is triggered ?

  You haven't entered a valid number!

  
• In the code below, what response will be printed if a ZeroDivisionError is triggered?

  You can't divide by 0 ! What were you thinking?

  
• The code below asks the user to input a number that they can divide by 999 , and this value will be displayed - However, if an invalid value is entered, a ValueError occurs - And if you input 0, a ZeroDivisionError occurs