CODEWITHSUNDEEP
pythonjson
Evan Emolo
Evan Emolo

Reputation: 1670

Removing JSON property in array of objects

I have a JSON array that I'm cleaning up in Python. I want to remove the imageData property:

data.json

[{"title": "foo", "imageData": "xyz123"},
{"title": "bar", "imageData": "abc123"},
{"title": "baz", "imageData": "def456"}]

I am setting up a list comprehension to remove the property, but I'm not sure how to create the variable that focuses on imageData:

import json

with open('data.json') as json_data:
    data = json.load(json_data)
    clean_data = [ item for item in data if not item['imageData'] ]
    # Write `clean_data` to new json file

When I print the list comprehension, it returns an empty array. What do I have to correct to get this working properly?

Upvotes: 23

Views: 63928

Answers (4)

Stefano Sanfilippo
Stefano Sanfilippo

Reputation: 33046

An easy solution to your problem is deleting the unwanted key in place, with del:

import json

with open('data.json') as json_data:
    data = json.load(json_data)
    for element in data: 
        del element['imageData']

You should add some safety checks, but you get the idea.

Upvotes: 40

wwii
wwii

Reputation: 23753

How about:
clean_data = [k:v for k,v in data.iteritems() if k != 'imageData']

Or a dictionary expresion/comprehension if you want a dictionary:
clean_data = {k:v for k,v in data.iteritems() if k != 'imageData'}

Upvotes: 1

Daniel Roseman
Daniel Roseman

Reputation: 599560

If not all the elements have an imageData key, then using del will cause an KeyError exception. You could guard against that by using pop with a default:

for item in data: 
    item.pop('image', None)

Upvotes: 18

user1907906
user1907906

Reputation: 

[ item for item in data if not item['imageData'] ]

is empty becaus all have imageData. You are just testing for it, not removing it.

Loop over date and del item['imageData'] on each item.

Upvotes: 2

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