Python 3.8 Tuple to variable index?-CodePudding

I have a variable, jdata, that holds data read from a JSON data file. It consists of many levels of dictionaries and lists of dictionaries. I have a search routine that returns a tuple containing path-like information to the element I want to access. I'm struggling to turn the tuple into a variable index. For example, the search routine may return ('name', 5, 'pic', 3). So I want to access jdata['name'][5]['pic'][3]. The number of levels down into the data can change for each search, so the tuple length is variable.

Addendum: for everyone asking for code and what I've done: I don't have code to share because I don't know how to do it and that's why I'm asking here. My first thought was to try and create the text for accessing the variable, for the example above,

    "x = jdata['name'][5]['pic'][3]"

and then looking for a python way of executing that line of code. I figured there has to be a more elegant solution.

I thought the description of tuple to variable access was pretty straight forward, but here is an expanded version of my problem.

jdata = { 'thing1': 1,
          'name': [
              {},
              {},
              {},
              {},
              {},
              {   'thing11': 1,
                  'pic': [ 'LocationOfPicA',
                           'LocationOfPicB',
                           'LocationOfPicC',
                           'LocationOfPicD',
                           'LocationOfPicE'],
                  'thing12: 2},
              {},
              {} ],
          'thing2': 2}

I searched for 'PicD' and my search code returns: ('name', 5, 'pic', 3)

Now I want to do some stuff, for example, accessing the value 'LocationOfPicD', copy the file located there to some other place, and update the value of 'LocationOfPicD' to the new value. All of this I can code. I just need to be able to turn the tuple into an accessible variable.

Edit: I was just reading about mutability in python. Instead of generating a path to an element in the dictionary, I think I can just assign that element value to a variable (x, for example) that gets passed back up the recursion chain of the initial search. From my understanding, I can change x and that also changes the element within the jdata variable. If that doesn't work, I can resort to using the eval() command on my generated text statement using the tuple as originally planned.

CodePudding user response：

If I understand the problem correctly, you just need to avoid getting the lowest level item by value. So, you could do something like

indexes = ('name', 5, 'pic', 3)

x = jdata

for index in indexes[:-1]:
    x = x[index]

x[indexes[-1]] = <new_value_here>

CodePudding user response：

Easy and quick recursive implementation.

def get_d(d, tup, ind=0):
    if ind == len(tup) - 1:  # last item just return value
        return d[tup[ind]]
    return get_d(d[tup[ind]], tup, ind   1)  # else keep getting sub-item

# input input datastructure (could be dict, list, or gettable item) and tuple of items to recursively get
value = get_d(jdata, ('name', 5, 'pic', 3))

Note: this implementation is super basic and has no error handling. It's just here to give you an idea on how it could be done.