如何在另一个YAML文件中包含一个YAML文件?

我有两个YAML文件，“A”和“B”，我希望将A的内容插入到B中，要么拼接到现有的数据结构中，就像数组一样，要么作为元素的子元素，就像某个散列键的值一样。

这可能吗?怎么做?如果不是，是否有指向规范引用的指针?

当前回答

结合其他答案，这里是一个简短的解决方案，没有重载Loader类，它可以与任何加载器操作文件:

import json
from pathlib import Path
from typing import Any

import yaml


def yaml_include_constructor(loader: yaml.BaseLoader, node: yaml.Node) -> Any:
    """Include file referenced with !include node"""

    # noinspection PyTypeChecker
    fp = Path(loader.name).parent.joinpath(loader.construct_scalar(node)).resolve()
    fe = fp.suffix.lstrip(".")

    with open(fp, 'r') as f:
        if fe in ("yaml", "yml"):
            return yaml.load(f, type(loader))
        elif fe in ("json", "jsn"):
            return json.load(f)
        else:
            return f.read()


def main():
    loader = yaml.SafeLoader  # Works with any loader
    loader.add_constructor("!include", yaml_include_constructor)

    with open(...) as f:
        yml = yaml.load(f, loader)

PyTypeChecker的存在是为了防止pep检查警告预期类型'ScalarNode'，得到'节点'而不是通过节点:yaml。节点到loader.construct_scalar()。

如果yaml。加载输入流不是文件流，因为loader.name在这种情况下不包含路径:

class Reader(object):
    ...
    def __init__(self, stream):
        ...
        if isinstance(stream, str):
            self.name = "<unicode string>"
            ...
        elif isinstance(stream, bytes):
            self.name = "<byte string>"
            ...
        else:
            self.name = getattr(stream, 'name', "<file>")
            ...

在我的用例中，我知道只包含YAML文件，所以解决方案可以进一步简化:

def yaml_include_constructor(loader: yaml.Loader, node: yaml.Node) -> Any:
    """Include YAML file referenced with !include node"""
    with open(Path(loader.name).parent.joinpath(loader.construct_yaml_str(node)).resolve(), 'r') as f:
        return yaml.load(f, type(loader))


Loader = yaml.SafeLoader  # Works with any loader
Loader.add_constructor("!include", yaml_include_constructor)


def main():
    with open(...) as f:
        yml = yaml.load(f, Loader=Loader)

甚至是使用lambda的一行代码:

Loader = yaml.SafeLoader  # Works with any loader
Loader.add_constructor("!include",
                       lambda l, n: yaml.load(Path(l.name).parent.joinpath(l.construct_scalar(n)).read_text(), type(l)))

2022-12-08 10:25:27

其他回答

据我所知，YAML中不直接支持include，你必须自己提供一种机制，然而，这通常很容易做到。

我在我的python应用程序中使用YAML作为配置语言，在这种情况下经常定义这样的约定:

>>> main.yml <<<
includes: [ wibble.yml, wobble.yml]

然后在我的(python)代码中:

import yaml
cfg = yaml.load(open("main.yml"))
for inc in cfg.get("includes", []):
   cfg.update(yaml.load(open(inc)))

唯一的缺点是include中的变量将总是覆盖main中的变量，并且没有办法通过改变“includes:”语句在main中出现的位置来改变优先级。yml文件。

稍微不同的一点是，YAML不支持include，因为它并不是像基于文件的标记那样专门设计的。如果你在AJAX请求的响应中得到一个包含，它意味着什么?

2012-01-23 18:45:22

不，标准YAML不包括任何类型的“import”或“include”语句。

2013-03-15 16:39:30

可能在问问题时不支持，但你可以将其他YAML文件导入其中:

imports: [/your_location_to_yaml_file/Util.area.yaml]

虽然我没有任何在线参考资料，但这对我来说很有用。

2014-08-01 07:50:19

标准YAML 1.2本身不包括这个特性。尽管如此，许多实现提供了一些扩展来实现这一点。

我给出了一种使用Java和snakeyaml:1.24(用于解析/发出YAML文件的Java库)来实现它的方法，它允许创建一个自定义YAML标记来实现以下目标(你会看到我用它来加载在几个YAML文件中定义的测试套件，并且我让它作为一个目标测试:节点的包含列表工作):

# ... yaml prev stuff

tests: !include
  - '1.hello-test-suite.yaml'
  - '3.foo-test-suite.yaml'
  - '2.bar-test-suite.yaml'

# ... more yaml document

下面是允许处理!include标记的单类Java。文件从classpath (Maven资源目录)加载:

/**
 * Custom YAML loader. It adds support to the custom !include tag which allows splitting a YAML file across several
 * files for a better organization of YAML tests.
 */
@Slf4j   // <-- This is a Lombok annotation to auto-generate logger
public class MyYamlLoader {

    private static final Constructor CUSTOM_CONSTRUCTOR = new MyYamlConstructor();

    private MyYamlLoader() {
    }

    /**
     * Parse the only YAML document in a stream and produce the Java Map. It provides support for the custom !include
     * YAML tag to split YAML contents across several files.
     */
    public static Map<String, Object> load(InputStream inputStream) {
        return new Yaml(CUSTOM_CONSTRUCTOR)
                .load(inputStream);
    }


    /**
     * Custom SnakeYAML constructor that registers custom tags.
     */
    private static class MyYamlConstructor extends Constructor {

        private static final String TAG_INCLUDE = "!include";

        MyYamlConstructor() {
            // Register custom tags
            yamlConstructors.put(new Tag(TAG_INCLUDE), new IncludeConstruct());
        }

        /**
         * The actual include tag construct.
         */
        private static class IncludeConstruct implements Construct {

            @Override
            public Object construct(Node node) {
                List<Node> inclusions = castToSequenceNode(node);
                return parseInclusions(inclusions);
            }

            @Override
            public void construct2ndStep(Node node, Object object) {
                // do nothing
            }

            private List<Node> castToSequenceNode(Node node) {
                try {
                    return ((SequenceNode) node).getValue();

                } catch (ClassCastException e) {
                    throw new IllegalArgumentException(String.format("The !import value must be a sequence node, but " +
                            "'%s' found.", node));
                }
            }

            private Object parseInclusions(List<Node> inclusions) {

                List<InputStream> inputStreams = inputStreams(inclusions);

                try (final SequenceInputStream sequencedInputStream =
                             new SequenceInputStream(Collections.enumeration(inputStreams))) {

                    return new Yaml(CUSTOM_CONSTRUCTOR)
                            .load(sequencedInputStream);

                } catch (IOException e) {
                    log.error("Error closing the stream.", e);
                    return null;
                }
            }

            private List<InputStream> inputStreams(List<Node> scalarNodes) {
                return scalarNodes.stream()
                        .map(this::inputStream)
                        .collect(toList());
            }

            private InputStream inputStream(Node scalarNode) {
                String filePath = castToScalarNode(scalarNode).getValue();
                final InputStream is = getClass().getClassLoader().getResourceAsStream(filePath);
                Assert.notNull(is, String.format("Resource file %s not found.", filePath));
                return is;
            }

            private ScalarNode castToScalarNode(Node scalarNode) {
                try {
                    return ((ScalarNode) scalarNode);

                } catch (ClassCastException e) {
                    throw new IllegalArgumentException(String.format("The value must be a scalar node, but '%s' found" +
                            ".", scalarNode));
                }
            }
        }

    }

}

2019-07-29 17:05:57