Python ZeroDivisionError — What It Means & How to Fix It

What Does This Error Mean?

A ZeroDivisionError means your code tried to divide a number by zero. Division by zero is mathematically undefined — there is no valid answer — so Python raises an error instead of returning a nonsense result. This usually happens when a variable that should hold a non-zero value ends up being zero, often due to unexpected input or logic.

Affected Models

Python 2.x
Python 3.x
All Python versions

Common Causes

Directly writing something like x = 10 / 0 in your code
A variable used as a divisor ends up being zero because of user input or a calculation result
Dividing by a count or total that is zero because a list or dataset is empty
Using the modulo operator (%) with zero as the divisor (10 % 0 also raises this error)
A calculation that produces zero as an intermediate result, which is then used as a divisor

How to Fix It

Find the division in your code that caused the error. The error message shows the line number.

Look for a / or % operator on that line.
Add a check before the division: if denominator != 0: then do the division. Otherwise, handle the zero case separately.

Example: result = numerator / denominator if denominator != 0 else 0
If the divisor comes from user input, validate it before using it. Tell the user to enter a non-zero number.

Always assume user input might be zero or invalid.
If you are calculating an average of a list, check that the list is not empty before dividing by its length.

Example: average = sum(items) / len(items) if items else 0
Use a try/except block to catch ZeroDivisionError if it is expected to occasionally happen and you want to handle it gracefully.

Example: try: result = a / b except ZeroDivisionError: result = 0

When to Call a Professional

ZeroDivisionErrors are always something you can fix yourself. The fix is simply to check that the divisor is not zero before dividing. Think about whether zero is a valid value in your context and handle it with a meaningful result.

Frequently Asked Questions

What does Python return if I divide a float by zero?

If you divide a float by zero in Python, you also get a ZeroDivisionError. This is different from some other languages where float division by zero returns 'Infinity'. Python is strict — it raises an error either way.

What about 0 divided by 0?

That also raises a ZeroDivisionError in Python. Mathematically, 0/0 is 'indeterminate' (not just undefined), but Python treats it the same as any division by zero. The error message says 'division by zero' in both cases.

Should I always use try/except for division?

Not always — it depends on your code. If zero is never a valid divisor, it is better to validate the value and raise a clear error message than to silently return 0. Use try/except when zero is a legitimate edge case that you want to handle without crashing. Use if-checks when zero means bad input that should be rejected.