JSFiddle - React, Tailwind, and code Playground

JavaScript

function pydict (item) {
    if(!(this instanceof pydict)) {
       return new pydict(item);
    }
    var self = this;
    self._item = item;
    self.get = function(name, def) {
        var val = self._item[name];
        return new pydict(val === undefined || val === null ? def : val);
    };
    self.value = function() {
       return self._item;
    };
    return self;
};

// now use it by wrapping your js object
var output = {deeply: { nested: { array: [] } } };
var array = pydict(output).get('deeply', {}).get('nested', {}).get('array', []).value();
console.log(array);