What is the difference between error and exception in Python?

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| Python | Programming | Code |

In this tutorial, you will learn the difference between errors and exceptions in Python, as well as the proper way to handle them to create more robust and reliable programs.

By the end, you will understand when an issue in your code is an error or an exception, and how to handle exceptions to prevent your program from crashing unexpectedly.

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What is an error in Python?

An error is a problem in the code that prevents the program from running correctly.
There are different types of errors:

• Syntax errors (SyntaxError): Occur when the code does not follow the language rules.
• Indentation errors (IndentationError): Happen when the code indentation is incorrect.
• Type errors (TypeError): Arise when a data type is used incorrectly.

Example of a syntax error:

print("Hello world"  # Missing closing parenthesis

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What is an exception in Python?

An exception is an event that occurs during program execution that disrupts its normal flow. Exceptions can be caught and handled to prevent the program from failing completely.

• ZeroDivisionError: Division by zero.
• FileNotFoundError: File not found.
• ValueError: Invalid value for an operation.

Example of an exception:

try:
    result = 10 / 0
except ZeroDivisionError:
    print("Cannot divide by zero")

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Key differences between error and exception

Concept	Error	Exception
When	Detected before or during execution	Detected during execution
Handling	Usually cannot be handled	Can be handled with try / except
Example	SyntaxError, IndentationError	ZeroDivisionError, ValueError

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How to handle exceptions in Python

Python provides the try-except statement to catch and handle exceptions:

try:
    number = int(input("Enter a number: "))
    print(10 / number)
except ValueError:
    print("You must enter a valid number")
except ZeroDivisionError:
    print("Cannot divide by zero")
finally:
    print("Operation completed")

finally always runs, regardless of whether an exception occurred or not.

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Best practices

• Always anticipate potential errors that may occur in your code.
• Use specific exceptions instead of a general except:.
• Do not ignore important exceptions: properly handling errors improves program reliability.

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DJC > Tutorials