List of lists - merge sublists with common elements

[Gribouillis]

This is a version of the problem of finding the connected components of a graph. One approach would be to use a library that already has a function to do that, such as networkx.

>>> import networkx as nx
>>> g = nx.Graph()
>>> ipath = [['a','b'],['c','d'],['b','e'],['f','g'],['a','h'],['i','c']]
>>> for p in ipath:
...     g.add_edges_from(zip(p, p[1:]))
... 
>>> for c in nx.connected_components(g):
...     print(c)
... 
{'e', 'h', 'a', 'b'}
{'i', 'c', 'd'}
{'g', 'f'}