如何使用python和ruamel更新此yaml文件？

Question

我有一个test.yaml文件，其中包含以下内容：

school_ids:
  school1: "001"

  #important school2
  school2: "002"


targets:
  neighborhood1:
    schools:
      - school1-paloalto
    teachers:
      - 33
  neighborhood2:
    schools:
      - school2-paloalto
    teachers:
      - 35

我想使用ruamel将文件更新为如下所示：

school_ids:
  school1: "001"

  #important school2
  school2: "002"

  school3: "003"


targets:
  neighborhood1:
    schools:
      - school1-paloalto
    teachers:
      - 33
  neighborhood2:
    schools:
      - school2-paloalto
    teachers:
      - 35
  neighborhood3:
    schools:
      - school3-paloalto
    teachers:
      - 31

如何使用ruamel通过保留注释来更新文件以获得所需的输出

以下是我目前掌握的情况：

import sys
from ruamel.yaml import YAML

inp = open('/targets.yaml', 'r').read()

yaml = YAML()

code = yaml.load(inp)
account_ids = code['school_ids']
account_ids['new_school'] = "003"
#yaml.dump(account_ids, sys.stdout)


targets = code['targets']
new_target = dict(neighborhood3=dict(schools=["school3-paloalto"], teachers=["31"]))
yaml = YAML()
yaml.indent(mapping=2, sequence=3, offset=2)
yaml.dump(new_target, sys.stdout)

Answer 1

您只是在转储从头创建的new_target，而不是使用code甚至targets。 相反，您应该使用code这个 加载并扩展与其根级别键关联的值，然后转储code：

import sys
from pathlib import Path
from ruamel.yaml import YAML

inp = Path('test.yaml')

yaml = YAML()

code = yaml.load(inp)
school_ids = code['school_ids']
school_ids['school3'] = "003"


targets = code['targets']
targets['neighborhood3'] = dict(schools=["school3-paloalto"], teachers=["31"])
yaml = YAML()
yaml.indent(mapping=2, sequence=4, offset=2)
yaml.dump(code, sys.stdout)

其中：

school_ids:
  school1: '001'

  #important school2
  school2: '002'


  school3: '003'
targets:
  neighborhood1:
    schools:
      - school1-paloalto
    teachers:
      - 33
  neighborhood2:
    schools:
      - school2-paloalto
    teachers:
      - 35
  neighborhood3:
    schools:
      - school3-paloalto
    teachers:
      - '31'

请注意，您的序列缩进需要至少比您的序列缩进大2 偏移（2个位置有空间容纳-+空间）

输出在键school2之后有emtpy行，这就是 在解析过程中，这些与关联。可以将其移动到新关键点，但 这不是小事。如果您需要这样做（这对于语义来说并不重要） 然后看看我的答案 here