ApexDelight

Assert vs Raise Python: What is Difference?

• apexdelight
• March 20, 2025March 20, 2025
• 0

Both assert and raise are used for handling errors in Python, but they serve different purposes:

1. assert (Assertion)

• Used for debugging and checking conditions.
• If the condition is False, it raises an AssertionError.
• Can be disabled when running Python with the -O (optimize) flag.
• Syntax: pythonCopy codeassert condition, "Error message"

Example:

pythonCopy codex = 10
assert x > 5, "x should be greater than 5"  # No error
assert x < 5, "x should be less than 5"  # Raises AssertionError

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2. raise (Exception Handling)

• Used to manually raise exceptions.
• Can raise built-in or custom exceptions.
• Not disabled in optimized mode.
• Syntax: pythonCopy coderaise ExceptionType("Error message")

Example:

pythonCopy codex = -1
if x < 0:
    raise ValueError("x cannot be negative")  # Raises ValueError

---

Key Differences

Feature	assert	raise
Purpose	Debugging	Error handling
Exception Raised	AssertionError	Any exception
Can be Disabled	Yes (-O flag)	No
Usage Scenario	Checking conditions during development	Handling errors in production

When to Use What?

• Use assert for debugging checks that shouldn’t run in production.
• Use raise for handling errors and enforcing business logic.

Let me know if you need more clarification! 🚀