ITS 320 Colorado State University Python Error Handling Discussion Forum

Post 1: Main post prompt: (Reply to this post with 100 words or more)
Review the following content on Python 3 Errors and Exceptions https://docs.python.org/3/tutorial/errors.html
After studying this technical note, explain various ways in which Python 3 programming exceptions can be handled. Why is it important to handle Python 3 exceptions? Provide a code example of Python 3 exception handling and at least one reference to support your findings.

Post 2: Reply to this post agreeing or disagreeing & expanding on the point in 75 words or more:
“Even if a statement or expression is syntactically correct, it may cause an error when an attempt is made to execute it” (https://docs.python.org/3/tutorial/errors.html). Python handles errors thrown during program execution with try/except statements. This allows us as the programmer to include blocks of code that check for common user errors and then output an error message that informs the user on what exactly they did wrong. Without exception handling, a program would simply crash without any further output to alert what went wrong. A generic except statement will execute if any exception is thrown:

def double(number):
return number * 2

user_input = ”
while user_input != ‘q’:
try:
x = int(input(“Please enter a number: “))
result = double(x)
print(result)
except:
print(“An error occurred during the calculation. Please try again.”)

user_input = input(“Enter any key (‘q’ to quit): “)

In order to show a specialized error message for a specific exception type, the error name must be included in the exception statement. Python has several built-in exceptions and we can also define new exceptions as needed. The above example has been modified to specify the ValueError exception. The output statement then specifies what exactly the user did wrong, which if the exception is thrown then the user did not enter a valid number:

def double(number):
return number * 2

user_input = ”
while user_input != ‘q’:
try:
x = int(input(“Please enter a number: “))
result = double(x)
print(result)

except ValueError as err:

print(“Error occurred. Please enter a valid number.”)

user_input = input(“Enter any key (‘q’ to quit): “)

Post 3: Reply to this post agreeing or disagreeing & expanding on the point in 75 words or more:

I learned that if a statement or expression is syntactically correct, it may cause an error when an attempt is made to execute it. Errors detected during execution are called exceptions. In python exceptions are handled with try except block. Try except block can handle multiple types of exceptions in the program. Try except block works as a statement under try and except gets executed first. If no exception occurs the statement under except is skipped. If exception occurs, then statement under except gets executed

For example:

try:

x = 11/0

print(x)

if we want to capture only a particular type exception then we can include exception type in except statement.

For example:

def value_error_exception():

try:

x = int(“dog”)

print(x)

except ValueError as error:

print(“Exception Type : ValueError”,error)

We can also include an else and finally to try except block. Statements under else is executed when no exception occurs and statements under finally are always executed.

A Python program terminates as soon as it encounters an error. So, if this happens you should review your code for errors. Error and exception handling increase the robustness of your code, and it guards against potential failures that would cause your program to exit in an uncontrolled fashion.