import glob
import json
from json import JSONDecodeError
from os.path import basename

foo_by_file = {}

for file in glob.glob('**/*.json', recursive=True):
    filename = basename(file)
    with open(file) as file_contents:
        try:
            data = json.load(file_contents)
            foo_by_file[filename] = data.get('foo', 'NOT FOUND')
        except JSONDecodeError:
            foo_by_file[filename] = 'INVALID JSON'

for file, foo in sorted(foo_by_file.items()):
    print(f'{file} {foo}')