Minimal JSON-to-YAML converter with smarter multi-line handling

json2yaml

#!/usr/bin/env python3

"""
Convert a JSON file to a YAML file
"""

import sys
import json
import ruamel.yaml as yaml

def str_presenter(dumper, data):
    if '\n' in data or '\t' in data: # check for complex or multiline strings
        return dumper.represent_scalar('tag:yaml.org,2002:str', data, style='|')
    return dumper.represent_scalar('tag:yaml.org,2002:str', data)
yaml.add_representer(str, str_presenter)

with open(sys.argv[1]) as f:
    view = json.load(f)
    if len(sys.argv) > 2:
        if (sys.argv[2] == '+') and sys.argv[1].endswith('.json'):
            outname = sys.argv[1][:-5] + '.yml'
        else:
            outname = sys.argv[2]
        with open(outname, "w") as fout:
            yaml.dump(view, fout)
    else:
        yaml.dump(view, sys.stdout)