Alright, floating point numbers those ***** little buggers that can cause headaches for even the most seasoned programmers out there. No worries, though! In this guide, we’ll be diving into some of the quirks and nuances of working with floats in Python (and other programming languages), all while keeping things lighthearted and casual.
First off, let’s start with a little background on what floating point numbers actually are. Essentially, they’re just approximations of decimal values that can be represented using binary digits think of them as the digital equivalent of writing 3.14 instead of 3 (which is obviously much more cumbersome).
Now, here’s where things get a little tricky: due to the limitations of our hardware and software, floating point numbers can only represent certain values with a high degree of accuracy. This means that some decimal values simply cannot be represented exactly using binary digits instead, they have to be rounded or truncated in order to fit within the available space.
This is where we run into issues like “floating point errors” and “rounding errors,” which can cause unexpected results when working with floating point numbers. For example:
> 0.1 + 0.2 == 0.3
False
Yep, you read that right in Python (and many other programming languages), adding two small decimal values together and expecting a result of exactly 0.3 is not guaranteed to work as expected! This is because the binary representation of these numbers cannot be represented with perfect accuracy using floating point arithmetic.
So what can we do about this? Well, one option is to use string formatting or other techniques to limit the number of significant digits displayed in our output this can help us avoid some of the more egregious errors that arise from working with floating point numbers. For example:
> format(math.pi, ‘.12g’) # give 12 significant digits
‘3.14159265359’
Another option is to simply accept the fact that floating point errors are a natural part of working with these numbers after all, they’re just approximations! In many cases, we can live with a certain degree of error and still get the results we need.
Of course, there are times when we absolutely cannot tolerate any kind of error in our calculations for example, if we’re working on financial software or other applications where precision is critical. In these situations, it may be worth exploring alternative approaches to floating point arithmetic (such as using fixed-point numbers or arbitrary-precision libraries) that can provide greater accuracy and reliability.