Following on from this question: JSON to YAML in Python : How to get correct string manipulation?

I’d like to have specific key names (regardless of nesting depth) always given a double-quote style. This is the starting point:

import sys
from ruamel.yaml import YAML

data = {
    'simple': 'nonquoted',
    'grouping': 'quoted',
    'deep': {
        'simple': 'nonquoted',
        'grouping': 'quoted',
    }
}

def test():
    yaml = YAML()
    yaml.default_flow_style = False
    yaml.dump(data, sys.stdout)

test()

which currently gives:

simple: nonquoted
grouping: quoted
deep:
  simple: nonquoted
  grouping: quoted

Id like it to be:

simple: nonquoted
grouping: "quoted"
deep:
  simple: nonquoted
  grouping: "quoted"

I’ve looked at adding representers, but I got stuck. Can someone show me how?

I have Python 3.10.13 and ruamel.yaml 0.18.6.

Update: I’m able to do this by walking the tree, applying the ruamel specific type DoubleQuotedScalarString

but maybe there is a way to do it on dump?

# Function to preprocess in-place the dictionary to quote values for specific keys
def preprocess_dict_in_place(data, doubleQuoteKeys={}):
    if isinstance(data, dict):
        for key in list(data.keys()):
            if key in doubleQuoteKeys:
                data[key] = DoubleQuotedScalarString(data[key])
            elif isinstance(data[key], dict):
                preprocess_dict_in_place(data[key], doubleQuoteKeys)
            elif isinstance(data[key], list):
                for index in range(len(data[key])):
                    preprocess_dict_in_place(data[key][index], doubleQuoteKeys)
    elif isinstance(data, list):
        for index in range(len(data)):
            preprocess_dict_in_place(data[index])