确实没有这个功能ruamel.yaml<=0.12.18
在键之前的行上插入注释,但有一个函数可以在结构的开头设置注释:.yaml_set_start_comment
。这样您就可以设置要添加的三个注释中的两个:
import sys
import ruamel.yaml
yaml_str = """\
xyz:
a: 1 # comment 1
b: 2
test1:
test2:
test3: 3
"""
data = ruamel.yaml.round_trip_load(yaml_str)
data['test1'].yaml_set_start_comment('before test2', indent=2)
data['test1']['test2'].yaml_set_start_comment('after test2', indent=4)
ruamel.yaml.round_trip_dump(data, sys.stdout)
gives:
xyz:
a: 1 # comment 1
b: 2
test1:
# before test2
test2:
# after test2
test3: 3
实际上有一个“注释”,由值之间的空行组成xyz
and test1
,但是如果您将注释附加到该结构,然后在之前插入一个新键test1
事情并没有如你所愿。因此要做的就是在 key 之前明确插入注释test1
。您可以往返加载您的预期输出以查看内部Comment
应该看起来像:
yaml_str_out = """\
xyz:
a: 1 # comment 1
b: 2
# before test1 (top level)
test1:
# before test2
test2:
# before test3
test3: 3
"""
test = ruamel.yaml.round_trip_load(yaml_str_out)
print(test.ca)
给出(将其包装起来以便于查看):
Comment(comment=None,
items={'test1': [None,
[CommentToken(value='# before test1 (top level)\n')],
None,
[CommentToken(value='# before test2\n')]]})
如你所见# before test2
被认为是键后的注释。
并在做test['test1'].yaml_set_start_comment('xxxxx', indent=2)
将要
与关联的评论没有任何影响test1
否决了这一点并且# xxxxx
will not出现在转储中。
有了这些信息和一些背景知识,我改编了一些代码yaml_set_start_comment()
(假设原始进口和yaml_str
):
def yscbak(self, key, before=None, indent=0, after=None, after_indent=None):
"""
expects comment (before/after) to be without `#` and possible have multiple lines
"""
from ruamel.yaml.error import Mark
from ruamel.yaml.tokens import CommentToken
def comment_token(s, mark):
# handle empty lines as having no comment
return CommentToken(('# ' if s else '') + s + '\n', mark, None)
if after_indent is None:
after_indent = indent + 2
if before and before[-1] == '\n':
before = before[:-1] # strip final newline if there
if after and after[-1] == '\n':
after = after[:-1] # strip final newline if there
start_mark = Mark(None, None, None, indent, None, None)
c = self.ca.items.setdefault(key, [None, [], None, None])
if before:
for com in before.split('\n'):
c[1].append(comment_token(com, start_mark))
if after:
start_mark = Mark(None, None, None, after_indent, None, None)
if c[3] is None:
c[3] = []
for com in after.split('\n'):
c[3].append(comment_token(com, start_mark))
if not hasattr(ruamel.yaml.comments.CommentedMap,
'yaml_set_comment_before_after_key'):
ruamel.yaml.comments.CommentedMap.yaml_set_comment_before_after_key = yscbak
data = ruamel.yaml.round_trip_load(yaml_str)
data.yaml_set_comment_before_after_key('test1', 'before test1 (top level)',
after='before test2', after_indent=2)
data['test1']['test2'].yaml_set_start_comment('after test2', indent=4)
ruamel.yaml.round_trip_dump(data, sys.stdout)
and get:
xyz:
a: 1 # comment 1
b: 2
# before test1 (top level)
test1:
# before test2
test2:
# after test2
test3: 3
测试与hasattr
是为了确保在添加这样的函数时不会覆盖它ruamel.yaml
顺便说一句:所有注释都是 YAML 中的行尾注释,其中一些注释之前可能只是有效的 YAML。