Numeric keys in YAML files

user_1341120 0
Viewed 782

Is there any way to stringify numeric keys in a YAML file? I have a sample input file as so:

foo: bar
123: New York
food: Cheese
23.61 : max_value

I'm using the ruamel package to process my files - is there anything available in the loading or dumping calls that could perform the conversion so it would look like:

foo: bar
'123': New York
food: Cheese
'23.61' : max_value

or even all the keys ...

'foo': bar
'123': New York
'food': Cheese
'23.61': max_value

I looked through the API but couldn't see anything obvious ...

ruamel.yaml pyyaml yaml
1 Answers

There is no loading option that makes all keys strings, but you can do that after loading with a small recursive function:

import sys
import ruamel.yaml

yaml_str = """\
foo: bar
123: New York
food: Cheese
23.61 : max_value
"""

def keys2string(d):
    if isinstance(d, dict):
        for idx, k in enumerate(list(d.keys())):
            if not isinstance(k, str):
                sk = str(k)
                d.insert(idx, str(k), d.pop(k))
                k = sk
            keys2string(d[k])
    elif isinstance(d, list):
        for e in d:
            keys2string(e)


yaml = ruamel.yaml.YAML()
yaml.preserve_quotes = True
data = yaml.load(yaml_str)
keys2string(data)
yaml.dump(data, sys.stdout)

which gives:

foo: bar
'123': New York
food: Cheese
'23.61': max_value

The use of .insert() is one possible way of preserving the order of the keys (i.e. have the stringified keys be in the place of their original numeric keys).

user_13079050
Related