在 Python 中解析逻辑 JSON 数据

Question

I wonder if there exists some library to parse a JSON that contains logical operators to transform it into a flat query string.

Let's say as input I get:

{
    "Children":[
       {
          "ID":1,
       },
       {
          "ID":2,
       },
       {
          "Children":[
             {
                "ID":3,
             },
             {
                "ID":4,
             }
          ],
          "Type":"Or"
       }
    ],
    "Type":"And"
 }

And I want to convert it into simply:

(3 Or 4) AND 1 And 2

How would you do this in Python?

Answer 1

It depends on what your precise expectations are; in particular, this problem is a lot easier if you're OK with redundant parentheses.

Here's a simple recursive function with inadequate error checking (ie it's likely to raise an exception if the JSON doesn't precisely conform to expectations):

def json_to_formula(j):
    if 'Children' in j:                                                                
        return '(' + f" {j['Type']} ".join(map(json_to_formula,
                                           j['Children'])) + ')'
    else:
        return str(j['ID'])