在Python中将具有3列的文本文件转换为dict的嵌套dict

Question

我有一个txt文件如下：

#FromNodeId  ToNodeId    Weight
B   A   5
B   D   1
B   G   2
A   B   5
A   D   3
A   E   12
A   F   5
D   B   1
D   G   1
D   E   1
D   A   3
G   B   2
G   D   1
G   C   2
C   G   2
C   E   1
C   F   16
E   A   12
E   D   1
E   C   1
E   F   2
F   A   5
F   E   2
F   C   16

我想将其转换为 python 中字典的字典，如下所示：

graph = {
'B': {'A': 5, 'D': 1, 'G': 2},
'A': {'B': 5, 'D': 3, 'E': 12, 'F' :5},
'D': {'B': 1, 'G': 1, 'E': 1, 'A': 3},
'G': {'B': 2, 'D': 1, 'C': 2},
'C': {'G': 2, 'E': 1, 'F': 16},
'E': {'A': 12, 'D': 1, 'C': 1, 'F': 2},
'F': {'A': 5, 'E': 2, 'C': 16}}

我该怎么做？

Answer 1

import csv, collections


tree = collections.defaultdict(dict)
with open(filepath) as fd: 
    reader = csv.reader(fd, delimiter = ' ', skipinitialspace = True)
    for row in reader:
        tree[row[0]][row[1]] = row[2]

Answer 2

您可以读取数据并按第一个值 (FromNodeId) 分组：

import itertools, re
file_data = [[*a, int(b)] for *a, b in [re.split('\s+', i.strip('\n')) for i in open('filename.txt')]]
last_results = {a:dict(i[1:] for i in b) for a, b in itertools.groupby(sorted(file_data, key=lambda x:x[0]), key=lambda x:x[0])}

输出：

{'A': {'B': 5, 'D': 3, 'E': 12, 'F': 5}, 'B': {'A': 5, 'D': 1, 'G': 2}, 'C': {'G': 2, 'E': 1, 'F': 16}, 'D': {'B': 1, 'G': 1, 'E': 1, 'A': 3}, 'E': {'A': 12, 'D': 1, 'C': 1, 'F': 2}, 'F': {'A': 5, 'E': 2, 'C': 16}, 'G': {'B': 2, 'D': 1, 'C': 2}}

Answer 3

您将原始代码注释为：

g = nx.read_edgelist('sample2.txt', nodetype=str, data=(('Weight', int),), create_using=nx.DiGraph())
graph = nx.to_dict_of_dicts(g,edge_data = None)

返回类似：

{'A': {'B': {'Weight': 5},
  'D': {'Weight': 3},
  'E': {'Weight': 12},
  'F': {'Weight': 5}},
 'B': {'A': {'Weight': 5}, 'D': {'Weight': 1}, 'G': {'Weight': 2}},
 'C': {'E': {'Weight': 1}, 'F': {'Weight': 16}, 'G': {'Weight': 2}},
 'D': {'A': {'Weight': 3},
  'B': {'Weight': 1},
  'E': {'Weight': 1},
  'G': {'Weight': 1}},
 'E': {'A': {'Weight': 12},
  'C': {'Weight': 1},
  'D': {'Weight': 1},
  'F': {'Weight': 2}},
 'F': {'A': {'Weight': 5}, 'C': {'Weight': 16}, 'E': {'Weight': 2}},
 'G': {'B': {'Weight': 2}, 'C': {'Weight': 2}, 'D': {'Weight': 1}}}

这很接近，您可以使用字典理解手动清理它：

clean_graph = {a: {b: edge['Weight'] for b, edge in a_vals.items()} for a, a_vals in graph.items()}

产生：

{'A': {'B': 5, 'D': 3, 'E': 12, 'F': 5},
 'B': {'A': 5, 'D': 1, 'G': 2},
 'C': {'E': 1, 'F': 16, 'G': 2},
 'D': {'A': 3, 'B': 1, 'E': 1, 'G': 1},
 'E': {'A': 12, 'C': 1, 'D': 1, 'F': 2},
 'F': {'A': 5, 'C': 16, 'E': 2},
 'G': {'B': 2, 'C': 2, 'D': 1}}