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Basics of Error Handling | Error Handling
Python Advanced Concepts
course content

Course Content

Python Advanced Concepts

Python Advanced Concepts

1. Modules and Imports
2. Error Handling
3. File Handling
4. Pytest Framework
5. Unittest Framework
6. Iterators and Generators

book
Basics of Error Handling

Welcome to the first chapter of our journey into error handling in Python! 🎉 Error handling is a critical skill for any programmer, as it allows your programs to respond appropriately to unexpected issues. This chapter covers the types of errors and exceptions you might encounter and how to handle them using the try and except blocks.

Types of Errors and Exceptions in Python

Python categorizes errors into two main types: syntax errors and exceptions.

Syntax Errors

Syntax errors occur when the parser detects an incorrect statement. This could be a typo, a missing parenthesis, or incorrect indentation. Here's an example:

1
print("Hello world"
copy

This will result in a syntax error (SyntaxError) because the closing parenthesis is missing.

Exceptions or Run-Time Error

Exceptions are errors that are detected during execution. Common exceptions include:

  • IndexError: trying to access an index that does not exist;
  • ValueError: passing an argument with the wrong value;
  • TypeError: mismatch of data type, such as adding a string to an integer;
  • ZeroDivisionError: dividing a number by zero;
  • FileNotFoundError: trying to access a file that doesn't exist.

Here is an exception hierarchy where each lower-level error inherits from the one above it. This means that if you catch a higher-level exception, such as Exception, it will also catch all derived 'child' errors. While it's not necessary to know every single error, those highlighted in yellow are the most common and are particularly important to be aware of.

The try, except Block

To handle exceptions effectively, Python uses the try and except blocks. This allows the program to continue even if an error occurs.

Example of try, except Block

1234567
try: # Attempt to divide by zero result = 10 / 0 print("The result is", result) except ZeroDivisionError: # This code runs if the ZeroDivisionError is raised print("Attempted to divide by zero.")
copy

If the division were possible (i.e., dividing by a number other than zero), the print statement within the try block would execute, and the except block would be skipped. The except block only executes when the specific error it is designed to catch is raised.

Let’s practice error handling by writing a script that simulates error conditions and uses the try and except blocks.

Task
test

Swipe to show code editor

Write a script that handles different types of errors using basic operations.

#Use comments as helpful tips for solving this task 😉

Switch to desktopSwitch to desktop for real-world practiceContinue from where you are using one of the options below
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How can we improve it?

Thanks for your feedback!

Section 2. Chapter 1
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book
Basics of Error Handling

Welcome to the first chapter of our journey into error handling in Python! 🎉 Error handling is a critical skill for any programmer, as it allows your programs to respond appropriately to unexpected issues. This chapter covers the types of errors and exceptions you might encounter and how to handle them using the try and except blocks.

Types of Errors and Exceptions in Python

Python categorizes errors into two main types: syntax errors and exceptions.

Syntax Errors

Syntax errors occur when the parser detects an incorrect statement. This could be a typo, a missing parenthesis, or incorrect indentation. Here's an example:

1
print("Hello world"
copy

This will result in a syntax error (SyntaxError) because the closing parenthesis is missing.

Exceptions or Run-Time Error

Exceptions are errors that are detected during execution. Common exceptions include:

  • IndexError: trying to access an index that does not exist;
  • ValueError: passing an argument with the wrong value;
  • TypeError: mismatch of data type, such as adding a string to an integer;
  • ZeroDivisionError: dividing a number by zero;
  • FileNotFoundError: trying to access a file that doesn't exist.

Here is an exception hierarchy where each lower-level error inherits from the one above it. This means that if you catch a higher-level exception, such as Exception, it will also catch all derived 'child' errors. While it's not necessary to know every single error, those highlighted in yellow are the most common and are particularly important to be aware of.

The try, except Block

To handle exceptions effectively, Python uses the try and except blocks. This allows the program to continue even if an error occurs.

Example of try, except Block

1234567
try: # Attempt to divide by zero result = 10 / 0 print("The result is", result) except ZeroDivisionError: # This code runs if the ZeroDivisionError is raised print("Attempted to divide by zero.")
copy

If the division were possible (i.e., dividing by a number other than zero), the print statement within the try block would execute, and the except block would be skipped. The except block only executes when the specific error it is designed to catch is raised.

Let’s practice error handling by writing a script that simulates error conditions and uses the try and except blocks.

Task
test

Swipe to show code editor

Write a script that handles different types of errors using basic operations.

#Use comments as helpful tips for solving this task 😉

Switch to desktopSwitch to desktop for real-world practiceContinue from where you are using one of the options below
Everything was clear?

How can we improve it?

Thanks for your feedback!

Section 2. Chapter 1
Switch to desktopSwitch to desktop for real-world practiceContinue from where you are using one of the options below
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