在 Python 中使用 PyYAML 操作 yml 文件，yaml 默认 load 进来是个字典，所以无法保持原本的顺序，要想不改变原本的 yaml 结构，更新 yaml 文件内容需要用到以下方法
from collections import OrderedDict
import yaml
def ordered_yaml_load(yaml_path, Loader=yaml.Loader,
object_pairs_hook=OrderedDict):
class OrderedLoader(Loader):
pass
def construct_mapping(loader, node):
loader.flatten_mapping(node)
return object_pairs_hook(loader.construct_pairs(node))
OrderedLoader.add_constructor(
yaml.resolver.BaseResolver.DEFAULT_MAPPING_TAG,
construct_mapping)
with open(yaml_path) as stream:
return yaml.load(stream, OrderedLoader)
def ordered_yaml_dump(data, stream=None, Dumper=yaml.SafeDumper, **kwds):
class OrderedDumper(Dumper):
pass
def _dict_representer(dumper, data):
return dumper.represent_mapping(
yaml.resolver.BaseResolver.DEFAULT_MAPPING_TAG,
data.items())
OrderedDumper.add_representer(OrderedDict, _dict_representer)
return yaml.dump(data, stream, OrderedDumper, **kwds)
# load yaml file
yaml_dict = ordered_yaml_load(yaml_file_path)
# dump new yaml file
with open(yaml_file_path, 'w') as f:
ordered_yaml_dump(new_yaml_dict, f, default_flow_style=False)
