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https://github.com/kislyuk/yq

Command-line YAML, XML, TOML processor - jq wrapper for YAML/XML/TOML documents
https://github.com/kislyuk/yq

cli command-line jq json xml yaml yml

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Command-line YAML, XML, TOML processor - jq wrapper for YAML/XML/TOML documents

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yq: Command-line YAML/XML/TOML processor - jq wrapper for YAML, XML, TOML documents

===================================================================================



Installation

------------

::



    pip install yq



Before using ``yq``, you also have to install its dependency, ``jq``. See the `jq installation instructions

`_ for details and directions specific to your platform.



On macOS, ``yq`` is also available on `Homebrew `_: use ``brew install python-yq``.



Synopsis

--------



``yq`` takes YAML input, converts it to JSON, and pipes it to `jq `_::



    cat input.yml | yq .foo.bar



Like in ``jq``, you can also specify input filename(s) as arguments::



    yq .foo.bar input.yml



By default, no conversion of ``jq`` output is done. Use the ``--yaml-output``/``-y`` option to convert it back into YAML::



    cat input.yml | yq -y .foo.bar



Mapping key order is preserved. By default, custom `YAML tags `_ and

`styles `_ in the input are ignored. Use the ``--yaml-roundtrip``/``-Y``

option to preserve YAML tags and styles by representing them as extra items in their enclosing mappings and sequences

while in JSON::



    yq -Y .foo.bar input.yml



yq can be called as a module if needed. With ``-y/-Y``, files can be edited in place like with ``sed -i``::



    python -m yq -Y --indentless --in-place '.["current-context"] = "staging-cluster"' ~/.kube/config



Use the ``--width``/``-w`` option to pass the line wrap width for string literals. Use

``--explicit-start``/``--explicit-end`` to emit YAML start/end markers even when processing a single document. All other

command line arguments are forwarded to ``jq``. ``yq`` forwards the exit code ``jq`` produced, unless there was an error

in YAML parsing, in which case the exit code is 1. See the `jq manual `_ for more

details on ``jq`` features and options.



Because YAML treats JSON as a dialect of YAML, you can use yq to convert JSON to YAML: ``yq -y . < in.json > out.yml``.



Preserving tags and styles using the ``-Y`` (``--yaml-roundtrip``) option

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



The ``-Y`` option helps preserve custom `string styles `_ and

`tags `_ in your document. For example, consider the following

document (an `AWS CloudFormation `_ template fragment)::



    Resources:

      ElasticLoadBalancer:

        Type: 'AWS::ElasticLoadBalancing::LoadBalancer'

        Properties:

          AvailabilityZones: !GetAZs ''

          Instances:

            - !Ref Ec2Instance1

            - !Ref Ec2Instance2

          Description: >-

            Load balancer for Big Important Service.



            Good thing it's managed by this template.



Passing this document through ``yq -y .Resources.ElasticLoadBalancer`` will drop custom tags, such as ``!Ref``,

and styles, such as the `folded `_ style of the ``Description`` field::



    Type: AWS::ElasticLoadBalancing::LoadBalancer

    Properties:

      AvailabilityZones: ''

      Instances:

        - Ec2Instance1

        - Ec2Instance2

      Description: 'Load balancer for Big Important Service.



        Good thing it''s managed by this template.'



By contrast, passing it through ``yq -Y .Resources.ElasticLoadBalancer`` will preserve tags and styles::



    Type: 'AWS::ElasticLoadBalancing::LoadBalancer'

    Properties:

      AvailabilityZones: !GetAZs ''

      Instances:

        - !Ref 'Ec2Instance1'

        - !Ref 'Ec2Instance2'

      Description: >-

        Load balancer for Big Important Service.



        Good thing it's managed by this template.



To accomplish this in ``-Y`` mode, yq carries extra metadata (mapping pairs and sequence values) in the JSON

representation of your document for any custom tags or styles that it finds. When converting the JSON back into YAML, it

parses this metadata, re-applies the tags and styles, and discards the extra pairs and values.



.. warning ::



 The ``-Y`` option is incompatible with jq filters that do not expect the extra information injected into the document

 to preserve the YAML formatting. For example, a jq filter that counts entries in the Instances array will come up with

 4 entries instead of 2. A filter that expects all array entries to be mappings may break due to the presence of string

 metadata keys. Check your jq filter for compatibility/semantic validity when using the ``-Y`` option.



yq does not support passing YAML comments into the JSON representation used by jq, or roundtripping such comments.



XML support

-----------

``yq`` also supports XML. The ``yq`` package installs an executable, ``xq``, which

`transcodes XML to JSON `_ using

`xmltodict `_ and pipes it to ``jq``. Roundtrip transcoding is available with

the ``xq --xml-output``/``xq -x`` option. Multiple XML documents can be passed in separate files/streams as

``xq a.xml b.xml``. Use ``--xml-item-depth`` to descend into large documents, streaming their contents without loading

the full doc into memory (for example, stream a `Wikipedia database dump `_ with

``cat enwiki-*.xml.bz2 | bunzip2 | xq . --xml-item-depth=2``). Entity expansion and DTD resolution is disabled to avoid

XML parsing vulnerabilities. Use ``python -m yq.xq`` if you want to ensure a specific Python runtime.



TOML support

------------

``yq`` supports `TOML `_ as well. The ``yq`` package installs an executable, ``tomlq``, which uses the

`tomlkit library `_ to transcode TOML to JSON, then pipes it to ``jq``. Roundtrip

transcoding is available with the ``tomlq --toml-output``/``tomlq -t`` option. Use ``python -m yq.tomlq`` if you want to

ensure a specific Python runtime.



.. admonition:: Compatibility note



 This package's release series available on PyPI begins with version 2.0.0. Versions of ``yq`` prior to 2.0.0 are

 distributed by https://github.com/abesto/yq and are not related to this package. No guarantees of compatibility are

 made between abesto/yq and kislyuk/yq. This package follows the `Semantic Versioning 2.0.0 `_

 standard. To ensure proper operation, declare dependency version ranges according to SemVer.



Authors

-------

* Andrey Kislyuk



Links

-----

* `Project home page (GitHub) `_

* `Documentation `_

* `Package distribution (PyPI) `_

* `Change log `_

* `jq `_ - the command-line JSON processor utility powering ``yq``



Bugs

~~~~

Please report bugs, issues, feature requests, etc. on `GitHub `_.



License

-------

Licensed under the terms of the `Apache License, Version 2.0 `_.



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