Instructions

Course Outcome: 4. Explain the use of lists and dictionaries in Python programming

Course Outcome: 6. Summarize the use of files and exceptions in Python programming 

“””

This is the flower box, and it should be at the beginning of each assignment.

You must add comments to your code
Program Name: Wk4_firstname_lastname.py
Student Name: Ymmas Azaba
Course: ENTD220
Instructor: My instructor
Date: Any Day

Copy Wrong: This is my work.

“””

ASSIGNMENT

You are going to enhance the prior assignment by implementing exceptions!

***** You must tell me where you implemented the exception and why. *****

• Show me 2 test cases that will trap the errors.
• Sample output
  • Enter first number between -10 and 20 –> add
  • Error –> could not convert string to float: 'add'    <<<< first trap
  • Enter first number between -10 and 20 –> 10
  • Enter second number between -10 and 20 –> 0
  • Error –> float division by zero <<< second trap

Submission Instructions:

• Make sure that you save your code in a text file in this format.
• W4_firstname_lastname.py

HINTS:

"""

   comment block

"""

# def functions

def add …

def sub…

def …

def isinrange() or  checknum()

while True:

   try:

         ## Get user inputs

         ## Do calculation and print results

   except Exception as e: 
         print("Error –>",e)
         continue 

print thank you for using…

# Trapping Errors

# Trapping error to avoid program breaking when error occurs

# errors can be user errors or system errors

# try-except should be on the program level
# try-except gives the user a chance to correct 
# the error instead of terminating the program
"""
Do I raise or return errors in Python?
Raise a python exception, and then wrap all of your self written functions in a try/except wrapper. 
Return a result that indicates there was an error. As easy as returning False if it didn't work, 
or returning a dictionary with an error field. What's the pro's and con's of each? Thoughts? 
Never return an error in the same place as a value.
https://www.w3schools.com/python/gloss_python_raise.asp
https://www.programiz.com/python-programming/exception-handling
"""
def div(n1,n2):

       return n1/n2

while True:
 try: 
    fnum=float(input("Enter first number –> "))
    snum=float(input("Enter second number –> "))
    print("The div = ", div(fnum,snum));
    break
 except Exception as e: 
    print(“Error: “,e)
    continue

Enter first number –> sam

ValueError: could not convert string to float: 'sam'

# Test 2

Enter first number –> 7

Enter second number –> 0