def _partition_at_level(dendrogram, level) :
	"""Return the partition of the nodes at the given level

	A dendrogram is a tree and each level is a partition of the graph nodes.
	Level 0 is the first partition, which contains the smallest snapshot_affiliations, and the best is len(dendrogram) - 1.
	The higher the level is, the bigger are the snapshot_affiliations

	"""
	partition = dendrogram[0].copy()
	for index in range(1, level + 1) :
		for node, community in partition.items() :
			partition[node] = dendrogram[index][community]
	return partition