updating a deep key in a Nested JSON file

Question

I have a json file which looks like this:

{
    "email": "abctest@xxx.com", 
    "firstName": "name01", 
    "surname": "Optional"
    "layer01": {
        "key1": "value1", 
        "key2": "value2", 
        "key3": "value3", 
        "key4": "value4", 
        "layer02": {
            "key1": "value1", 
            "key2": "value2"
        }, 
        "layer03": [
            {
                "inner_key01": "inner value01"
            }, 
            {
                "inner_key02": "inner_value02"
            }
        ]
    }, 
    "surname": "Required only$uid"
}

am expecting a update request as:

{
                "email": "XYZTEST@gmail.com",
                "firstName": "firstName",
                "layer01.key3": "newvalue03",
                "layer01.layer02.key1": "newvalue01"
            },

the deeper keys are separated using "."

am using python2.7. Can anyone advice me on this.. am really stuck at this!!

this is what i was working with:

def updateTemplate(self,templatename, data):
    template= self.getTemplatedata(templatename) # gets the python object with the data from original file

    for ref in data:
        k= ref
        keys= ref.split(".")
        temp= template
        if len(keys)>1:
            temp= template[keys[0]]
            for i in range(1,lens(keys)-1):
                print keys[i]
                if type(temp) is dict:
                    temp =temp[keys[i]]



            temp[keys[len(keys)-1]]= data[k]
            print temp

            template.update(temp)        
        else:
            template[k]= data[k]   
    print template  

update added a whole new key in the template object. I need to update the key in last temp to template object

the template object displayed this:

{   u'email': u'abctest@xxx.com',
    u'firstName': u'Valid AU$uid',
    u'key1': u'value1',
    u'key2': u'value2',
    u'key3': u'value03',
    u'key4': u'value4',
    u'layer01': {   u'key1': u'value1',
                    u'key2': u'value2',
                    u'key3': u'value03',
                    u'key4': u'value4',
                    u'layer02': {   u'key1': u'value01', u'key2': u'value2'},
                    u'layer03': [   {   u'inner_key01': u'inner value01'},
                                    {   u'inner_key02': u'inner_value02'}]},
    u'layer02': {   u'key1': u'value01', u'key2': u'value2'},
    u'layer03': [   {   u'inner_key01': u'inner value01'},
                    {   u'inner_key02': u'inner_value02'}],
    u'surname': u'Required only$uid'}

Answer 1

As much as I'd like to help you out, I find your code confusing, but I'll do my best. Here it goes

For starters, by temp= template do you mean to do temp= copy.deepcopy(template)? Remember to import copy Reference

I get that template is a dictionary, but what do you want to achieve by referencing template to temp, tweaking temp then adding

template.update(temp)

temp to template which in fact temp is a reference to template?

How about we scrap the code and start off fresh.

i.e. Input is

{
    "email": "XYZTEST@gmail.com",
    "firstName": "firstName",
    "layer01.key3": "newvalue03",
    "layer01.layer02.key1": "newvalue01"
}

Existing data is:

{
    "email": "abctest@xxx.com", 
    "firstName": "name01", 
    "surname": "Optional"
    "layer01": {
        "key1": "value1", 
        "key2": "value2", 
        "key3": "value3", 
        "key4": "value4", 
        "layer02": {
            "key1": "value1", 
            "key2": "value2"
        }, 
        "layer03": [
            {
                "inner_key01": "inner value01"
            }, 
            {
                "inner_key02": "inner_value02"
            }
        ]
    }, 
    "surname": "Required only$uid"
}

Expected Output:

{
    "email": "XYZTEST@gmail.com", 
    "firstName": "firstName", 
    "surname": "Optional"
    "layer01": {
        "key1": "value1", 
        "key2": "value2", 
        "key3": "newvalue03", 
        "key4": "value4", 
        "layer02": {
            "key1": "newvalue01", 
            "key2": "value2"
        }, 
        "layer03": [
            {
                "inner_key01": "inner value01"
            }, 
            {
                "inner_key02": "inner_value02"
            }
        ]
    }, 
    "surname": "Required only$uid"
}

Kindly confirm if this is the result your expecting, so I can help you with your brainstorming.

Answer 2

Your algorithm is really close but there's a few things in it that complicate things unnecessarily. This makes it easy to miss the key line that's causing the problem:

template.update(temp) 

temp is the child-most dictionary of the template but here you set the original template to have all it's children too. Comment this line out and it should work.

Some of the things that I cleaned up to make this line easier to find:

• Don't hardcode the case where there's only one element in the keys list. The loop can handle it.
• In Python, there's a nice shorthand for keys[len(keys)-1]: keys[-1]. See Negative index to Python list
• Instead of using enumerate and checking if the type of temp is a dict, simply don't loop over the last key (this could change the behaviour a bit for other input)
• Using pprint. It pretty prints things like lists and dictionaries.

Put together, a simplified version looks like this:

import pprint

def updateTemplate(self, templatename, data):
    template = self.getTemplatedata(templatename) # gets the python object with the data from original file

    for ref in data:
        keys = ref.split(".")
        temp = template
        for key_part in keys[:-1]:
            temp = temp[key_part]
        temp[keys[-1]] = data[ref] # Because dictionaries are mutable, this updates template too

    pprint.pprint(template)  

Hope this helps.