ZeroDivisionError: float division by zero in Python

The Python “ZeroDivisionError: float division by zero” is raised when we try to divide a float number and the second argument of this division is zero. You can solve this error by using an if statement or nesting your division within a try/except block.

Before going into details, let’s reproduce this error:

x = 20.0 #our float
y = 0
 
print(x/y) #ZeroDivisionError: float division by zero
Code language: Python (python)

This error is one of the many built-in errors for Python and exists because a division of a number by 0 tends toward infinity and this cannot be represented in a Python variable.

Use an if statement

You can simply write your code inside an if statement to take care of this exception. This if statement will check that y (the second argument of our division) is not equal to zero to calculate the result. If it indeed equals to zero, we’ll assign 0 to our result, even though it theoretically cannot be calculated.

x = 20.0 
y = 0

if y != 0:
   result = x/y
   print(f'The result is {result}')
else:
    result = 0
    print('The result cannot be calculated') 
Code language: Python (python)

Our code gets longer, but it will run no matter the value of y. If you want to shorten it, you can use a shorter version:

x = 20.0 
y = 0 

result = y and x/y #0
Code language: Python (python)

This syntax is less known but actually easy to understand:

• Python first evaluates if y returns True. Remember that 0 is handled as a falsy value in Python:

z = 0 
print(z == False) #True
Code language: Python (python)

• If y returns False (which is our case in our previous code), the value of y is returned (0)
• If it does not return False, then the result of x/y (our division) is returned

x = 20.0 
y = 0 

a = 10 
b = 20

result_1 = y and x/y #0
result_2 = a and a/b #0.5
Code language: Python (python)

Use a try/except block

Another approach to fix this error is to handle the exception using a try/except block. You can either create a generic block catching all exceptions:

x = 20.0
y = 0 

try:
    result = x/y 
except:
    result = 0 
Code language: Python (python)

Python will try to execute inside the try block and if it raises an error, it will then fall back to the except block. I’d recommend targeting a specific error type when you use this approach, to be sure to not catch another error accidentally:

x = 20.0 
y = 0 

try: 
    result = x/y 
except ZeroDivisionError:
    result = 0 
Code language: PHP (php)