将字符串格式的键值对图转换为字典。Python

Question

给定一个地图，用一串用逗号分隔的两位数字表示，比如 "12,23,34,45,56,67,78,81"，其中每对数字代表两个数字之间的路径。我们需要把这个字符串转换成一个图，图用字典表示，字典的键是起点（数字），值是从这个起点可以到达的目的地。例如，1:[2,8]，2:[3]，等等。

这是我非常糟糕的尝试：

def path(way):
x = way.split(',')
y = sorted(set(tele.replace(',','')))
graph = dict()
for i in x:
    for j in range(len(i)):
        for h in y:
            if h in i and i[j] != h:
                if h in graph:
                    graph[h].append((i[j]))
                else:
                    graph[h] = [(i[j])]
return graph

我打算在这之后实现广度优先搜索算法，以找到最佳路径。如果我的解释不清楚，我很抱歉。任何帮助都将非常感激，谢谢！

Answer 1

# this initializes values in the dictionary d with empty lists
# so that we can directly call .append() without checking "if key in keys"
from collections import defaultdict
d = defaultdict(list)

# your input string
s = "12,23,34,45,56,67,78,81"

# iterate through digit pairs
for pair in s.split(","):
  # get single digits from a pair
  fr = pair[0]
  to = pair[1]

  # add edges in both directions (undirected)
  d[fr].append(to)
  d[to].append(fr)

# see what we got
print d

结果

{'1': ['2', '8'], '3': ['2', '4'], '2': ['1', '3'], '5': ['4', '6'], '4': ['3', '5'], '7': ['6', '8'], '6': ['5', '7'], '8': ['7', '1']}