Using Ruamel.yaml, How Can I Make Vars With Newlines Be Multiline Without Quotes

I am generating YAML which serves as a protocol, and it contains some generated JSON inside of it. import json from ruamel import yaml jsonsample = { 'id': '123', 'type': 'customer

Solution 1:

You can do:

import sys
import json
from ruamel import yaml

jsonsample = { "id": "123", "type": "customer-account", "other": "..." }
myyamel = {}
myyamel['sample'] = {}
myyamel['sample']['description'] = "This example shows the structure of the message"
myyamel['sample']['content'] = json.dumps( jsonsample, indent=4, separators=(',', ': '))

yaml.scalarstring.walk_tree(myyamel)

yaml.round_trip_dump(myyamel, sys.stdout, default_style = None, default_flow_style=False, indent=2, block_seq_indent=2, line_break=0, explicit_start=True, version=(1,1))

which gives:

%YAML1.1---sample:description:Thisexampleshowsthestructureofthemessagecontent:|-
    {
        "id": "123",
        "type": "customer-account",
        "other": "..."
    }

Some notes:

• since you are using a normal dict the order in which your YAML is printed is implementation and key dependent. If you want the order to be fixed to your assignments use:

  myyamel['sample'] = yaml.comments.CommentedMap()
  

• you should never use print(yaml.round_trip_dump) if you print the return value, specify the stream to write to, that is more efficient.

• walk_tree converts all strings that have a newline in them to block style mode recursively. You can also explicitly do:

  myyamel['sample']['content'] = yaml.scalarstring.PreservedScalarString(json.dumps( jsonsample, indent=4, separators=(',', ': ')))
  

  in which case you don't need to call walk_tree()

---

Even though you are still working on Python 2, you should start getting used to using the print function instead of the print statement. For that include at the top of each of your Python files:

from __future__ import print_function