按元素顺序迭代字典

Question

给定

post = {"comments": [
{
"_id": 2, 
"detail": "info1",
"responses": [
{
"_id": 3,
"responses": [],
"detail": "info2"
}]
},
{
"_id": 0, 
"responses": [],
"detail": "info3",
}]
}

从视觉上看，这只是

[comment comment]
[child comment]
[parent comment]

我正试图遍历从第一条到最后一条的每条评论

所以info1然后info2然后info3

我的尝试

queue = []
comment1 = post['comments']
queue.append(comment1)
for responses in queue:
for comment in responses:
print(comment['detail'])
if(comment['responses'] != []):
queue.append(comment['responses'])

这会打印

info1
info3
info2

不管怎样，通过调整一下来得到我想要的？

Answer 1

您可以使用递归函数遍历注释树。有一种方法：

def replies_deep(comment):
print(comment['detail'])
for response in comment['responses']:  # Iterate over responses
replies_deep(response)  # Recurse into the response's responses
for top in post['comments']:
replies_deep(top)

Answer 2

您的代码之所以这么做，是因为它在队列的末尾添加了回复，而不是直接在它后面。要解决这个问题，您需要创建一个函数：

def process_comment(comment):
print(comment['detail'])
if(comment['responses'] !=  []):
for i in comment['responses']:
process_comment(i)
queue = []
comment1 = post['comments']
queue.append(comment1)
for responses in queue:
for comment in  responses:
process_comment(comment)

上面的代码应该可以工作。

Answer 3

试试这个代码；它使用递归函数来获取注释：

#Bad code, but simplest in this circumstance.
def iterate(arr):
global queue
for comment in arr:
queue.append(comment["detail"])
print(comment["detail"]) #For your debug.
iterate(comment["responses"])
post = {} #Put your data here
queue = []
iterate(post["comments"])

该函数反复调用自己，读取对答复的答复，直到完成为止。它会产生你想要的结果，在穿过之前先下树。