파이썬 NetworkX 사용법 - 예제

 

 

 

In [1]:

from IPython.core.display import display, HTML
display(HTML("<style>.container {width:90% !important;}</style>"))

 

 

 

NetworkX¶

참고
https://networkx.github.io/documentation/stable/tutorial.html
https://networkx.github.io/documentation/stable/reference/generated/networkx.convert_matrix.from_pandas_adjacency.html

In [2]:

import networkx as nx

 

무방향성 그래프¶

In [3]:

#객체 생성
g1 = nx.Graph()

In [4]:

#노드 추가
g1.add_node("a")
g1.add_node(1)
g1.add_node(2)
g1.add_node(3)

g1.add_nodes_from([11, 22])

In [5]:

#노드 제거
g1.remove_node(3)

In [6]:

#엣지 추가
g1.add_edge(1, "a")
g1.add_edge(1, 2)
g1.add_edge(1, 22)

g1.add_edges_from([(1, 2), (1, 11)])

In [7]:

#엣지 제거
g1.remove_edge(1, 22)

In [8]:

#그래프 그리기
nx.draw(g1, with_labels = True, font_weigth = "bold")

 

In [9]:

#degree 크기에 따른 node size 설정
d = dict(g1.degree)
nx.draw(g1, nodelist = d.keys(), node_size = [v * 100 for v in d.values()], with_labels = True, font_weigth = "bold")

 

In [10]:

#노드 현황
g1.nodes

Out[10]:

NodeView(('a', 1, 2, 11, 22))

In [11]:

#엣지 현황
g1.edges

Out[11]:

EdgeView([('a', 1), (1, 2), (1, 11)])

In [12]:

#degree
g1.degree

Out[12]:

DegreeView({'a': 1, 1: 3, 2: 1, 11: 1, 22: 0})

In [13]:

#인접
g1.adj

Out[13]:

AdjacencyView({'a': {1: {}}, 1: {'a': {}, 2: {}, 11: {}}, 2: {1: {}}, 11: {1: {}}, 22: {}})

In [14]:

#노드의 개수
g1.number_of_nodes()

Out[14]:

5

In [15]:

#엣지의 개수
g1.number_of_edges()

Out[15]:

3

In [16]:

#요약
print(nx.info(g1))

 

Name: 
Type: Graph
Number of nodes: 5
Number of edges: 3
Average degree:   1.2000

 

방향성 그래프¶

In [17]:

#객체 생성
g2 = nx.DiGraph()

g2.add_edges_from([(1, 2), (1, 3), (2, 4), (3, 4)])

nx.draw(g2, with_labels = True, font_weigth = "bold")

 

In [18]:

g2.degree

Out[18]:

DiDegreeView({1: 2, 2: 2, 3: 2, 4: 2})

In [19]:

g2.in_degree

Out[19]:

InDegreeView({1: 0, 2: 1, 3: 1, 4: 2})

In [20]:

g2.out_degree

Out[20]:

OutDegreeView({1: 2, 2: 1, 3: 1, 4: 0})

 

가중치 표시¶

In [27]:

g3 = nx.DiGraph() 

g3.add_weighted_edges_from([(1, 2, 3), (2, 3, 4)])
g3.add_edge(1, 3, weight = 6)

pos = nx.spring_layout(g3)
nx.draw(g3, pos = pos, with_labels = True)

labels = nx.get_edge_attributes(g3,'weight')
nx.draw_networkx_edge_labels(g3, pos, edge_labels = labels);

 

 

판다스 데이터프레임 사용¶

In [396]:

import pandas as pd

In [511]:

df = pd.DataFrame({'from': ['A', 'B', 'C', 'A', 'E', 'D'],
                   'to': ['D', 'A', 'E', 'C', 'A', 'E'],
                   'weight': [1, 2, 3, 4, 5, 6]})
df

Out[511]:

	from	to	weight
0	A	D	1
1	B	A	2
2	C	E	3
3	A	C	4
4	E	A	5
5	D	E	6

In [513]:

g = nx.from_pandas_edgelist(df, 'from', 'to', create_using = nx.DiGraph())
nx.draw(g, with_labels=True)