Question

我有3个节点和3种颜色（R，G，B），并且我试图用节点和颜色的所有可能组合来创建字典（因此其3 ^ 3 = 27种可能的组合）应该看起来像

{0:  {0: 'R', 1: 'R', 2: 'R'}, 1: {0: 'R', 1: 'R', 2: 'G'}, 3: etc

但是我的字典colorized_nodes只是不断更新，最后我只剩下了最后一个组合。我不明白这是怎么回事。我的代码如下：

import itertools

colorized_nodes=dict()
colorized=dict()

nodes = [1, 2, 3] 
colors = ['R','G','B'] 
nodes_count=len(nodes)
colors_count=len(colors)
all_combs=nodes_count**colors_count

#all possible combinations of colors
comb=itertools.product(colors, repeat=colors_count)
allcombs=list(comb)


for i in range (all_combs):
    for index,color in enumerate(allcombs[i]):
        colorized[index]=color
    colorized_nodes={**colorized_nodes, **colorized}
    print(colorized_nodes)
    colorized={}

print('checkpoint') 
print(colorized_nodes)

Answer 1

您的代码始终只使用一个键来存储内容-您可以在整个过程中使用enumerate来简化代码：

#all possible combinations of colors
comb=itertools.product(colors, repeat=colors_count)
allcombs=list(comb)

# see below for loop-equivalent
cols = {i:{ii:vv for ii,vv in enumerate(v)} for i,v in enumerate(allcombs)}
print(cols)

输出：

{0: {0: 'R', 1: 'R', 2: 'R'}, 1: {0: 'R', 1: 'R', 2: 'G'}, 2: {0: 'R', 1: 'R', 2: 'B'},
 3: {0: 'R', 1: 'G', 2: 'R'}, 4: {0: 'R', 1: 'G', 2: 'G'}, 5: {0: 'R', 1: 'G', 2: 'B'}, 
 6: {0: 'R', 1: 'B', 2: 'R'}, 7: {0: 'R', 1: 'B', 2: 'G'}, 8: {0: 'R', 1: 'B', 2: 'B'}, 
 9: {0: 'G', 1: 'R', 2: 'R'},10: {0: 'G', 1: 'R', 2: 'G'},11: {0: 'G', 1: 'R', 2: 'B'}, 
 12: {0: 'G', 1: 'G', 2: 'R'},13: {0: 'G', 1: 'G', 2: 'G'},14: {0: 'G', 1: 'G', 2: 'B'}, 
 15: {0: 'G', 1: 'B', 2: 'R'},16: {0: 'G', 1: 'B', 2: 'G'},17: {0: 'G', 1: 'B', 2: 'B'}, 
 18: {0: 'B', 1: 'R', 2: 'R'},19: {0: 'B', 1: 'R', 2: 'G'},20: {0: 'B', 1: 'R', 2: 'B'}, 
 21: {0: 'B', 1: 'G', 2: 'R'},22: {0: 'B', 1: 'G', 2: 'G'},23: {0: 'B', 1: 'G', 2: 'B'}, 
 24: {0: 'B', 1: 'B', 2: 'R'},25: {0: 'B', 1: 'B', 2: 'G'},26: {0: 'B', 1: 'B', 2: 'B'}}

dict理解等同于

for idx,part in enumerate(allcombs):
    colorized={}
    for index, color in enumerate(part):
        colorized[index]=color
    colorized_nodes[idx]=colorized

向嵌套的dict python添加字典

1 个答案: