Remove Duplicate items in legend

Taming the Legend: Kiss Those Duplicate Entries Goodbye in Matplotlib

Legends. We all need ’em, right? They’re the Rosetta Stone of your data viz, translating those squiggles and blobs into something meaningful. But let’s be honest, a cluttered legend is like a messy desk – nobody wants to deal with it. And duplicate entries? Ugh, the worst! They muddy the waters and can even lead folks to misinterpret your hard work. So, how do we wrangle those unruly legends and banish those pesky duplicates? Let’s dive in.

The Duplicate Dilemma: Why Does This Happen?

Ever wonder why you end up with the same thing listed twice (or more!) in your legend? Usually, it boils down to how Matplotlib automatically labels things. See, by default, it tries to create a legend entry for every labeled element you plot. Which is usually helpful! But if you’re looping through data or layering plots with identical categories, boom – you’ve got duplicates. It’s like Matplotlib is a little too helpful sometimes.

Time to Declutter: Your Arsenal of Solutions

Okay, enough complaining. Let’s get practical. Here are a few tried-and-true methods to evict those duplicate legend entries and restore order to your plots.

1. Dictionary Magic: The Pythonic Way

This is one of my favorites because it’s so darn elegant. Python dictionaries are like bouncers at a club – they don’t let duplicates in! We can use this to our advantage. Basically, we’re going to pair up the plot elements (the “handles”) with their labels, shove them into a dictionary, and poof, only the unique labels survive. Here’s the code:

python