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.
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.
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.
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.
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.
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.
- Andrey Kislyuk
- Project home page (GitHub)
- Documentation
- Package distribution (PyPI)
- Change log
- jq - the command-line JSON processor utility powering
yq
Please report bugs, issues, feature requests, etc. on GitHub.
Licensed under the terms of the Apache License, Version 2.0.
