Hierarchical Clustering customized Linkage function In my clustering project, I need to customize the linkage function, so that after each cluster merging I can update the inter-cluster distance in my own way. 

Currently I'm using scikit-learn AgglomerativeClustering, which seems not having this customizable feature. After a quick glance in scipy, no luck there either. Does anyone know any python hierarchical clustering toolkit that has customizable linkage?
Fork sklearn and implement it yourself! The linkage function is referenced in cluster/hierarchical.py as


  join_func = linkage_choices[linkage] 


and 


  coord_col = join_func(A[i], A[j], used_node, n_i, n_j)


If you have time, polish your code and submit a pull request when you're done.