Kmeans clustering with multiple columns containing strings
After some more research we found this library: https://github.com/nicodv/kmodes. 

The library k-modes is used for clustering categorical variables. It defines clusters based on the number of matching categories between data points. (This is in contrast to the more well-known k-means algorithm, which clusters numerical data based on Euclidean distance.) The k-prototypes algorithm combines k-modes and k-means and is able to cluster mixed numerical / categorical data.

Because the dataframe contains categorical data we can't visualize it in a scatterplot. So I added the number representing the cluster the row was assigned to, for every row to get some form of visualization.

Normally you can only cluster ordinal data, because clustering happens based on distance. So I don't know to what extent this is reliable.