ruamel.yaml 增删改查

pip install ruamel.yaml

读取：

from ruamel.yaml import YAML
from pathlib import Path

# default, if not specfied, is 'rt' (round-trip)
yaml = YAML(typ='safe')

# 参数doc是 an object that has the .read() method, a string or a pathlib.Path()
data = yaml.load(Path("test_out.yaml"))
print(data)

data2 = yaml.load("""a:
  b: 2
  c: 3
""")
print(data2)

写入：

from ruamel.yaml import YAML
from pathlib import Path

yaml = YAML()
yaml.indent(mapping=2, sequence=4, offset=2)


def tr(s):
    return s.replace('
', '<
')  # such output is not valid YAML!


# 可以传入一个处理字符串的函数，来处理需要输出的yaml文件中的内容
yaml.dump({'a': [1, 2]}, Path("test_out.yaml"), transform=tr)

修改：

a:
  - 1
  - 2
b:
  name: jim

from pathlib import Path
import ruamel.yaml

yaml = ruamel.yaml.YAML()
yaml.indent(mapping=2, sequence=4, offset=2)

data = yaml.load(Path("test_out.yaml"))

# 新增
data['a'].append({"b": 18})
data['a'].append(18)

# 给a中列表第一个值添加注释
data['a'].yaml_add_eol_comment('comment 4', 0)  # takes column of comment 1
# 给b中指定的字段添加注释
data['b'].yaml_add_eol_comment('comment 5', 'name')  # takes column of comment 2
#  column=10 指定注释的离行首的距离
data['a'].yaml_add_eol_comment('comment 7', 1, column=10)

yaml.dump(data, Path("test.yaml"))

from ruamel.yaml import YAML
from pathlib import Path

yaml_str = """
first_name: Art
middle name:
  Vandelay: 18
occupation: Architect  # This is an occupation comment
about: Art Vandelay is a fictional character that George invents...
"""

yaml = YAML()

data = yaml.load(yaml_str)
print(data)
data.insert(1, 'last name', {'Vandelay': 18})
yaml.indent(mapping=2, sequence=4, offset=2)
yaml.dump(data, Path('test.yaml'))

---分隔

a:
  - 1
  - 2
b:
  name: jim

---
c:
  - 1
  - 2

from pathlib import Path
import ruamel.yaml

yaml = ruamel.yaml.YAML()
yaml.indent(mapping=2, sequence=4, offset=2)

data = yaml.load_all(Path("test_out.yaml"))

print(list(data))