def test_edge_count(self):
g = Graph('sample_graph_1.txt')
assert g.edge_count() == 4
assert g.edge_count() != 0
other_g = Graph('sample_graph_2.txt')
assert other_g.edge_count() == 12
assert other_g.edge_count() != 0
another_g = Graph('sample_graph_3.txt')
assert another_g.edge_count() == 27
# make sure its not including empty parentheses or invalid data
assert another_g.edge_count() != 29
assert another_g.edge_count() != 31
assert another_g.edge_count() != 0
def test_empty_graph(self):
nothing = Graph('empty.txt')
assert nothing.vertex_count() == 0
assert nothing.edge_count() == 0
assert nothing.edge_list() == []
