How to recursively remove certain keys from a multi-dimensional(depth not known) python dictionary?
python
Solution
If you allow `remove_specific_key` (renamed `remove_keys`) to accept any object as its first argument, then you can simplify the code:
def remove_keys(obj, rubbish):
if isinstance(obj, dict):
obj = {
key: remove_keys(value, rubbish)
for key, value in obj.iteritems()
if key not in rubbish}
elif isinstance(obj, list):
obj = [remove_keys(item, rubbish)
for item in obj
if item not in rubbish]
return obj
Since you wish to remove more than one key, you might as well let `rubbish` be a set instead of one particular key. With the above code, you'd remove '_event' and 'length' keys with
product = remove_keys(product, set(['_event', 'length']))
Edit: `remove_key` uses dict comprehension, introduced in Python2.7. For older version of Python, the equivalent would be
obj = dict((key, remove_keys(value, rubbish))
for key, value in obj.iteritems()
if key not in rubbish)
Problem
I'm using kendoUI Grid in one of my projects. I retrieved a piece of data using their api and found that it added some "unwanted" data to my json/dictionary. After passing the json back to my Pyramid backend, I need to remove these keys. The problem is, the dictionary can be of whatever depth and I don't know the depth in advance. Example: ``` product = { id: "PR_12" name: "Blue shirt", description: "Flowery shirt for boys above 2 years old", _event: {<some unwanted data here>}, length: <some unwanted data>, items: [{_event: {<some rubbish data>}, length: <more rubbish>, price: 23.30, quantity: 34, color: "Red", size: "Large"}, {_event: {<some more rubbish data>}, length: <even more rubbish>, price: 34.50, quantity: 20, color: "Blue", size: "Large"} ....] } ``` I want to remove two keys in particular: "_event" & "length". I tried writing a recursive function to remove the data but I can't seem to get it right. Can someone please help? Here's what I have: ``` def remove_specific_key(the_dict, rubbish): for key in the_dict: if key == rubbish: the_dict.pop(key) else: # check for rubbish in sub dict if isinstance(the_dict[key], dict): remove_specific_key(the_dict[key], rubbish) # check for existence of rubbish in lists elif isinstance(the_dict[key], list): for item in the_dict[key]: if item == rubbish: the_dict[key].remove(item) return the_dict ```