yamlANYyamlmappingbasics
yaml
name: ExpressYou
plan: premium
active: trueMappings are the YAML equivalent of objects or dictionaries. Keys should be consistent and human readable.
YAML Basics
Core YAML syntax, indentation rules, maps, lists, and practical validation commands for day-one and day-100 YAML workflows.
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Scalars, maps, and sequences
Core YAML building blocks and the examples people search for most.
yamlANYyamlsequencelist
yaml
features:
- message generator
- fix this message
- screenshot to replySequences are the YAML equivalent of arrays or lists.
yamlANYyamlnestingindentation
yaml
app:
name: ExpressYou
pricing:
monthly: 7.99
yearly: 59.99
tools:
- coach me
- message generatorNested indentation controls structure. Spaces matter; tabs should be avoided.
yamlANYyamlscalarstypes
yaml
draft: null
enabled: true
max_retries: 3
price: 7.99Use plain scalars carefully. YAML has implicit typing rules, so quoting can help avoid ambiguity.
Validate and inspect YAML from the terminal
Practical commands that make YAML easier to work with in local and CI workflows.
bashANYyamlyamllintlint
bash
yamllint config.yaml`yamllint` is a standard first pass for catching indentation, trailing spaces, duplicate keys, and other issues.
bashANYyamlpythonvalidation
bash
python - <<'PY'
import yaml
with open('config.yaml') as f:
print(yaml.safe_load(f))
PYUseful when you already have Python and PyYAML available and want a fast sanity check.
bashANYyamlyqformat
bash
yq '.' config.yamlGreat for validating structure and making machine-generated YAML easier to inspect.
bashANYyamlkubernetesvalidation
bash
kubectl apply --dry-run=client -f deployment.yamlThis catches many structural issues in Kubernetes manifests before they hit the cluster.
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