图论算法（七）：networkx 获取节点的度 / 连边的数量

1. networkx 获取节点的度
无向图中，节点的度表示节点邻接的节点的数目，NetworkX中，通过degree()函数获取一个节点的度，

import networkx as nx

G = nx.Graph()

# add nodes
G.add_node(1, a = 'seds', d = '1.2')
G.add_node(2, a = 'sfdt', d = '1.2')
G.add_node(3, a = 'feds', d = '2.3')
G.add_node(4, a = 'sedf', d = '3.1')

# add edges
G.add_edge(1, 2)
G.add_edge(1, 3)
G.add_edge(2, 3)
G.add_edge(1, 4)

# print
print 'degree of node 1: ', G.degree(1)
print 'degree of node 2: ', G.degree(2)
print 'degree of node 3: ', G.degree(3)
print 'degree of node 4: ', G.degree(4)

2. networkx 获取连边的数量
无向图中，NetworkX通过size()函数获取图G中连边的数量，

import networkx as nx

G = nx.Graph()

# add nodes
G.add_node(1, a = 'seds', d = '1.2')
G.add_node(2, a = 'sfdt', d = '1.2')
G.add_node(3, a = 'feds', d = '2.3')
G.add_node(4, a = 'sedf', d = '3.1')

# add edges
G.add_edge(1, 2)
G.add_edge(1, 3)
G.add_edge(2, 3)
G.add_edge(1, 4)

# print
print 'number of edges:', G.size()

参考
1. https://networkx.github.io/documentation/networkx-1.9.1/reference/generated/networkx.Graph.degree.html
2. https://networkx.github.io/documentation/networkx-1.9.1/reference/generated/networkx.Graph.size.html