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Solve Pandas “ValueError: cannot reindex from a duplicate axis”

Recently, I’ve been working with Pandas DataFrames that had a DateTime as the index. When I tried reindexing the DataFrame (using the reindex method), I bumped into an error. Let’s find out what causes it and how to solve it. The Python error I’m talking about is: A “duplicate axis”?… 

Pandas: Solve ‘You are trying to merge on object and float64 columns’

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  • 2 min read

Pandas can be somewhat puzzling, sometimes. It has a ton load of functionalities, but that can make the syntax and methods obscure. Simply judging from the method name, the ‘join’ and ‘merge’ method could be the same thing. However, they aren’t. Here’s an error that I used to run into… 

Solve “columns overlap but no suffix specified” in Pandas

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  • 2 min read

Surprisingly, the Pandas error “columns overlap but no suffix specified”, is one I ran into surprisingly late. Solving it is usually very straightforward. We’ll tackle it in this blog post. First, let’s take a closer look at the error: “ValueError: columns overlap but no suffix specified: Index([<list of columns>], dtype=’object’)”… 

Undersampling a Pandas DataFrame

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In a previous post, I explained how you can sample two Pandas DataFrame exactly the same way. In this blog post, I want to use that helper function to undersample your predictors and target variable. When you are working with an imbalanced data set, it’s often good practice to under-… 

How to solve SettingWithCopyWarning when using the ‘inplace’ parameter in pandas

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  • 2 min read

The SettingWithCopyWarning message is a confusing warning to many who are new to Pandas. If you’ve ever taken a computer science course, you might be aware of passing/copying by value or by reference. Well, it very much applies to pandas DataFrames too. Let’s go. Basically, when you are slicing a…