Python Control Structures for Handling Exceptions

In this Python article we want to learn about Python Control Structures for Handling Exceptions, Python is one of the best programming language that is known for its simplicity. there is a key features of Python and that is the ability to handle exceptions, or errors that occur during the execution of a program. Exception handling is important for writing good code that can handle unexpected situations. in this article we want to talk about Python control structures for handling exceptions.

What are exceptions ?

Let’s first define exceptions before learning how to handle them in Python. A programming error is an exception. It takes place while the program is running. Python stops the program’s regular flow when an exception happens and raises an error. This error message gives details about the kind of exception that happened and where it happened.

Some common exceptions in Python include:

SyntaxError: A syntax error occurs when the code is not written correctly and violates the rules of the Python language.

NameError: A name error occurs when a variable or function name is not defined or cannot be found.
TypeError: A type error occurs when an operation or function is performed on an object of the wrong type.
ValueError: A value error occurs when a function or method is called with an argument that has an inappropriate value.

Handling exceptions in Python

For handling exceptions in Python, we can use a combination of try, except and finally blocks. this is the basic syntax for exception handling in Python:

try:
    # code block to be monitored for exceptions
except ExceptionType:
    # code block to be executed if an exception raised
finally:
    # code block to be executed regardless of whether an 
    # exception was raised or not

try:

# code block to be monitored for exceptions

except ExceptionType:

# code block to be executed if an exception raised

finally:

# code block to be executed regardless of whether an

# exception was raised or not

In this code try block contains the code that may raise an exception. if an exception occurs, Python jumps to the corresponding except block and executes the code within it. and finally block is optional and contains code that will be executed regardless of whether an exception was raised or not.

Let’s check the practical example about this concept

try:
    # divide by zero to raise an exception
    x = 10 / 0
except ZeroDivisionError:
    print("Error: division by zero")
finally:
    print("The 'try except' block is finished")

try:

# divide by zero to raise an exception

x = 10 / 0

except ZeroDivisionError:

print("Error: division by zero")

finally:

print("The 'try except' block is finished")

In this code ZeroDivisionError is raised, because we are dividing 10 by 0, which is not a legal mathematical operation. The exception is caught and a message is printed by the except block. After the exception is caught, the finally block is called, and it produces a message to show that the try block is complete.

Run the code and this will be the result

Python Control Structures for Handling Exceptions

Catching multiple exceptions

Sometimes, we need to catch multiple exceptions and handle them differently. we can do this by specifying multiple except blocks, each handling a different exception type. for example:

try:
    # code that may raise exceptions
except ValueError:
    # code to handle value errors
except TypeError:
    # code to handle type errors
except:
    # code to handle all other exceptions
finally:
    # code to be executed regardless of 
    # whether an exception was raised or not

try:

# code that may raise exceptions

except ValueError:

# code to handle value errors

except TypeError:

# code to handle type errors

except:

# code to handle all other exceptions

finally:

# code to be executed regardless of

# whether an exception was raised or not

Raising exceptions

In addition to catching exceptions, we can also raise our own exceptions when certain conditions are met. we do this using the raise keyword. for example:

x = -1

if x < 0:
    raise ValueError("x cannot be negative")

x = -1

if x < 0:

raise ValueError("x cannot be negative")

In this example, we are checking if x is negative. If it is, we raise a ValueError with a custom error message.

Learn More

Python Control Structures for Conditional Statements

What are exceptions ?

Handling exceptions in Python

Catching multiple exceptions

Raising exceptions

Learn More

Leave a Comment Cancel reply