index

Turning a polars dataframe to long format with explode

Tabular data is easier to process when columns contain singular values of the same data type for each row. However, sometimes data can be stored as a list in a single row.

Joram Mutenge

Arranging columns in a specific order using index in polars

Stacking dataframes vertically only works when the column names are the same and arranged in the same order. For example, if you have df1 with columns Name and Age, and df2 w…

Joram Mutenge

How to remove whitespace in column values using polars in python

In data science or data analysis, counting unique values is very common. However, having whitespace (empty space at the beginning or at the end) in your values can lead to…

Joram Mutenge

Your beautiful code doesn’t matter anymore (and that’s fine)

Your code doesn’t run in a vacuum. Your tools, your projects, your career all depend on a fast-moving ecosystem of languages, libraries, platforms, datasets, and now, AI.

Joram Mutenge

Most data analysts are stuck using mediocre tools thanks to the familiarity trap

Data analysts aren’t exactly known for their technical wizardry – at least not if “technical” means writing actual code that doesn’t make software engineers weep. In fact…

Joram Mutenge

Idea person or Thoughtful person: Which one are you?

If you’re working in an organization, you can’t escape meetings. They are part and parcel of day-to-day life in any workplace. But sometimes, it can feel like all you ever…

Joram Mutenge

The single most important lesson I learned from my retired boss

The day my boss retired, a small part of me died.

Joram Mutenge

Let me be the new host of The Data Scientist Show

I messaged Daliana Liu, host of The Data Scientist Show, on LinkedIn asking to become the new host. If you know her, please share this post so she sees it.

Joram Mutenge

I made my first pull request to the Marimo team

If you work extensively with data in Python, you’ll agree that Jupyter notebooks provide an excellent environment for data analysis. I’ve used Jupyter notebooks for a long…

Joram Mutenge

How to improve a bad graph with plotly

All data visualizations should, first and foremost, inform. Any visualization that falls short of this is simply data art. Data visualizations that are uninformative may be…

Joram Mutenge

Creating a desktop app using kivy in python

I love watching movies and TV shows, but there are just too many out there that it’s often difficult to pick what to watch. For years, I’ve been updating my database of…

Joram Mutenge

Using set theory to speed up your data analysis

Most data analysis tasks involve joining tables to get more data or filter out specific data. But what happens when the data you’re working with isn’t in a format that…

Joram Mutenge

How overlooking a small detail on a job interview can disqualify you for a position

A month ago, I interviewed a candidate for a junior data analyst position. Given how difficult it is to land an interview in the data field due to stiff competition, I…

Joram Mutenge

Ten polars functions that pros use and amateurs don’t

Polars is increasingly becoming a popular data analysis library, and my prediction is that more new data scientists and analysts will be starting with Polars rather than…

Joram Mutenge

Tranforming timeseries data with group by and group by dynamic in polars

Polars has become my go-to library for data analysis. Each client project brings new insights into the powerful functionality Polars offers. Recently, I worked on a project…

Joram Mutenge

What I learned about group by dynamic in polars while working on a client’s project

In the last client project I worked on, I learned something about the group_by_dynamic function in Polars. While what I learned was surprising, the fact that I learned it…

Joram Mutenge

How to create charts from The Economist magazine using plotly

We at Conterval have always been fans of the charts from The Economist magazine. No publication does a better job of creating static visualizations you can use in print. We…

Joram Mutenge

What tool should you use as a data analyst?

Data analysis is a hot field nowadays. Companies are opening up new data analyst positions, and many people want to become data analysts.

Joram Mutenge

How we helped a bakery generate forecast by bread type using polars

A few weeks ago, Conterval did a consulting gig for a medium-sized bakery. This bakery makes white and brown bread, which it sells to a major retail store here in the USA.…

Joram Mutenge