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)))
其他回答
您的问题没有要求使用Python解决方案，但这里有一个使用PyYAML的解决方案。
PyYAML允许您将自定义构造函数(例如!include)附加到YAML加载器。我已经包含了一个可以设置的根目录，以便这个解决方案支持相对和绝对文件引用。
基于类的解决方案
这是一个基于类的解决方案，避免了我原始响应的全局根变量。
请参阅以下要点，了解一个类似的、更健壮的Python 3解决方案，该解决方案使用元类注册自定义构造函数。
import yaml
import os
class Loader(yaml.SafeLoader):
def __init__(self, stream):
self._root = os.path.split(stream.name)[0]
super(Loader, self).__init__(stream)
def include(self, node):
filename = os.path.join(self._root, self.construct_scalar(node))
with open(filename, 'r') as f:
return yaml.load(f, Loader)
Loader.add_constructor('!include', Loader.include)
一个例子:
foo.yaml
a: 1
b:
- 1.43
- 543.55
c: !include bar.yaml
bar.yaml
- 3.6
- [1, 2, 3]
现在可以使用以下方法加载文件:
>>> with open('foo.yaml', 'r') as f:
>>> data = yaml.load(f, Loader)
>>> data
{'a': 1, 'b': [1.43, 543.55], 'c': [3.6, [1, 2, 3]]}
我认为@max - b使用的解决方案看起来很棒。但是，对于嵌套的包含，它没有成功。例如，如果config_1。Yaml包含config_2。Yaml，其中包括config_3。Yaml，装弹机有问题。但是，如果您在加载时简单地将新的加载器类指向它自己，它就可以工作!具体来说，如果我们将旧的_include函数替换为稍微修改过的版本:
def _include(self, loader, node):
oldRoot = self.root
filename = os.path.join(self.root, loader.construct_scalar(node))
self.root = os.path.dirname(filename)
data = yaml.load(open(filename, 'r'), loader = IncludeLoader)
self.root = oldRoot
return data
经过反思，我同意其他评论，嵌套加载一般不适合yaml，因为输入流可能不是一个文件，但它非常有用!
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));
}
}
}
}
}
使用Symfony，它对yaml的处理将间接地允许您嵌套yaml文件。诀窍在于使用参数选项。例如:
common.yml
parameters:
yaml_to_repeat:
option: "value"
foo:
- "bar"
- "baz"
config.yml
imports:
- { resource: common.yml }
whatever:
thing: "%yaml_to_repeat%"
other_thing: "%yaml_to_repeat%"
其结果将与:
whatever:
thing:
option: "value"
foo:
- "bar"
- "baz"
other_thing:
option: "value"
foo:
- "bar"
- "baz"
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)))
推荐文章
- 如何从同一个YAML文件的其他地方引用YAML“设置”?
- YAML多行阵列
- js:将一个组件包装成另一个组件
- Spring Boot YAML配置的字符串列表
- 在这个数据库中&，<<，*是什么意思?yml文件?
- 在YAML中管道符号的用途是什么?
- 我如何在Ruby中解析YAML文件?
- .yaml和.yml扩展名有什么区别?
- 如何在YAML中创建一个空数组?
- n -transclude是什么?
- 在春季引导中从命令行设置活动概要文件和配置位置
- 为什么-(3破折号/连字符)在yaml文件?
- YAML当前日期在rmarkdown
- 如何从Linux shell脚本解析YAML文件?
- YAML等价于JSON中的对象数组
