#397 AttributError when using yaml_set_comment_before_after_key

[Bastien gerard]

I have an error when using yaml_set_comment_before_after_key and setting a "before" coment, when an "after" comment exist already.

from ruamel.yaml import YAML

yaml = YAML()

yaml_str = """
stages:
  # some_comment
  - test
  - build
"""

data = yaml.load(yaml_str)
print(data.ca)
#Comment(start=None, items={ stages: [None, None, None, [CommentToken('# some_comment\n', line: 2, col: 2)]]})

data.yaml_set_comment_before_after_key("stages", before="test2")

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-3-a616e96e7f6f> in <module>
     12 data = yaml.load(yaml_str)
     13 data.ca
---> 14 data.yaml_set_comment_before_after_key("stages", before="test2")

~/.pyenv/versions/3.8.6/envs/gitlabci-jsonschema-lint/lib/python3.8/site-packages/ruamel/yaml/comments.py in yaml_set_comment_before_after_key(self, key, before, indent, after, after_indent)
    396         elif before:
    397             for com in before.split('\n'):
--> 398                 c[1].append(comment_token(com, start_mark))
    399         if after:
    400             start_mark = CommentMark(after_indent)

AttributeError: 'NoneType' object has no attribute 'append'

[Anthon van der Neut]

Thanks for reporting this is fixed in 0.17.15