Exception Handling (learnpython.org)

How amazing is this banner image? Anyway. Exception handling is a mechanism in Python that enables the detection and management of runtime errors or exceptional conditions. It prevents the abrupt termination of a program and provides a controlled way to handle and recover from errors, ensuring the stability and reliability of our code.

#Exception Handling
print(a)

#error
Traceback (most recent call last):
  File "", line 1, in 
NameError: name 'a' is not defined

In Python, exception handling involves the use of the try-except block. The try block contains the code that may raise an exception, while the except block specifies the actions to be taken when an exception occurs. Python provides various built-in exception types, such as ValueError, TypeError, and FileNotFoundError.

#Missing 'a' Variable  Error
def do_stuff_with_number(n):
    print(n)

def catch_this():
    the_list = (1, 2, 3, 4, 5)

    for i in range(20):
        try:
            do_stuff_with_number(the_list[i])
        except IndexError: # Raised when accessing a non-existing index of a list
            do_stuff_with_number(0)

catch_this()

Exception handling allows us to gracefully handle errors and manage program flow. By catching and handling exceptions, we can perform alternate actions, log errors, or prompt users for corrective actions, ensuring a smooth and uninterrupted execution of our programs.

Exception Handling Exercise Solution

#Code Completed
actor = {"name": "John Cleese", "rank": "awesome"}

def get_last_name():
    return actor["name"].split()[1]

get_last_name()
print("All exceptions caught! Good job!")
print("The actor's last name is %s" % get_last_name())

Proper exception handling leads to more reliable and maintainable code. It helps identify and resolve errors, improves code readability, and enhances the overall stability of our applications.