Empty strings in arrays are removed after parsing

[onilton]

When adding a empty string "" in array, it is removed after parsing:

Small example

from pyhocon import ConfigFactory
from pyhocon import HOCONConverter

conf = ConfigFactory.parse_string('''
features: [
    less noisy / less pedantic syntax
    "hey"
    ""
    # ability to write comments
]

features2 = ["a", "b", "", "d"]
''')
print(conf.as_plain_ordered_dict())
print(HOCONConverter.to_json(conf))
print(conf)

Prints

OrderedDict([('features', ['less noisy / less pedantic syntax', 'hey']), ('features2', ['a', 'b', 'd'])])
{
  "features": [
    "less noisy / less pedantic syntax",
    "hey"
  ],
  "features2": [
    "a",
    "b",
    "d"
  ]
}
ConfigTree([('features', ['less noisy / less pedantic syntax', 'hey']), ('features2', ['a', 'b', 'd'])])

When using the regular (scala) HOCON:
https://hocon-playground.herokuapp.com/

Output:

{
    "features" : [
        "less noisy / less pedantic syntax",
        "hey",
        ""
    ],
    "features2" : [
        "a",
        "b",
        "",
        "d"
    ]
}

[polopi]

Same issue

[bpb]

Same issue.

[davlee1972]

Added a pull request to fix this..

#334

[davlee1972]

Btw this is impacting my CSV text parsing code using..

https://arrow.apache.org/docs/python/generated/pyarrow.csv.ConvertOptions.html#pyarrow.csv.ConvertOptions

There is a null values option to treat certain string values like null, NULL, “”, etc.. Reading this setting in using yamls works fine, but switching to Hocon drops the “” from the list and I end up with errors like: Unable to convert “” to Integer.

[davlee1972]

Testing results: