# Get ZeroDivisionError: float division in python

## Get ZeroDivisionError: float division in python

The problem is here:

``````t = 365/365
``````

You are dividing two integers, so python is using integer division. In integer division, the quotient is rounded down. For example, `364/365` would be equal to `0`. (`365/365` works because it is equal to `1`, which is still `1` rounded down.)

Instead, use float division, like so.

``````t = 365.0/365.0
``````

In addition to cheekens answer, you can put the following at the top of your modules:

``````from __future__ import division
``````

Doing so will make the division operator work the way you want it to i.e always perform a (close approximation of) true mathematical division. The default behaviour of the division operator (where it performs truncating integer division if the arguments happen to be bound to integers) was inherited from C, but it was eventually realised that it was not a great fit for a dynamically typed language like Python. In Python 3, this no longer happens.

In my Python 2 modules, I almost always import division from `__future__`, so that I cant get caught out by accidentally passing integers to a division operation I dont expect to truncate.

Its worth noting that `from __future__ import ...` statements have to be the very first thing in your module (I think you can have comments and a docstring before it, nothing else). Its not really a normal import statement, even though it looks like one; it actually changes the way the Python interpreter reads your code, so it cant wait until runtime to be exectuted like a normal import statement. Also remember that `import __future__` does not have any of the magic effects of `from __future__ import ...`.

#### Get ZeroDivisionError: float division in python

Try this:

`````` exponent = math.exp(-(math.pow(x-mean,2)/(2*math.pow(stdev,2))))
``````

A `ZeroDivisionError` is encountered when you try to divide by zero.