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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: “columns overlap but no suffix specified: Index([<list of columns>], dtype=’object’)” When… 

Solving “Found unknown categories […] in column” with sklearn OneHotEncoder

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  • 1 min read

In this short blog post, I tackle an error related to a classic problem within machine learning: how to treat unseen categorical values and solve the “found unknown categories” error. Imagine you have a train and a test data set with the following values in a column: Train: [‘green’, ‘red’,… 

Solving “trend lines are not supported when marks are stacked” in Tableau

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  • 2 min read

When you have a scatter plot in Tableau, you often want to add a trend line to indicate a relationship between two variables. However, sometimes it appears that it’s impossible: it’s greyed out and there is a tooltip that says “trend lines are not supported when marks are stacked”. Let’s…