class Edge:
'''
An edge in a directed graph. Edges have a source and a target node.
Attributes:
source_node -- A resosuma.graph.node.Node, the source of the edge
target_node -- A resosuma.graph.node.Node, the target of the edge
label -- The label string of the edge
'''
def __init__(self, source: str, label: str, target: str):
'''
Constructor setting attributes.
Note that this function explicitly creates Node objects from
the source and target arguments.
Keyword arguments:
source -- the name of the source node
label -- the name of the edge
target -- the name of the target node
'''
self.source_node = Node(source)
self.label = label
self.target_node = Node(target)
def get_source(self):
return self.source_node
def get_target(self):
return self.target_node
def get_label(self):
return self.label
def __str__(self):
src = self.source_node.get_label()
trg = self.target_node.get_label()
return 'Edge: ' + src + ' > ' + self.label + ' > ' + trg
def __key(self):
return (self.source_node, self.label, self.target_node)
def __eq__(self, other):
return self.__key() == other.__key()
def __hash__(self):
return hash(self.__key())
def test_get_label():
n = Node("Test")
assert n.get_label() == "Test"