et's build a model using hierarchical clustering. Hierarchical clustering module is available from sklearn.cluster.AgglomerativeClustering. You can choose linkage type and metric. Please check its documentation for more details.

a$)$ Number of clusters vs distance threshold Oftentimes hierarchical clustering does not need to know the number of clusters in advance. Instead, one needs to choose threshold distance$/$similarity to cut the dendrogram later. The AgglomerativeClustering module lets you specify either the number of clusters $($n$\_$clusters$)$ or the threshold $($distance$\_$threshold$).$ Based on our data, which should we choose to set to which value and why?