YAML

Methods

✅ yaml (PyYAML - YAML Parser)

pythonCopyEditimport yaml

Method	Description
yaml.safe_load()	Loads YAML into Python (safe, preferred)
yaml.load()	Loads YAML (use only with Loader arg)
yaml.dump()	Dumps Python object into YAML
yaml.safe_dump()	Dumps safely without tags or custom types
yaml.load_all()	Loads multiple YAML documents
yaml.dump_all()	Dumps multiple documents to a stream

Example

Here are real-world DevOps/SRE scenarios using PyYAML, demonstrating each commonly used method for working with YAML in Python:

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✅ PyYAML — yaml Module DevOps Use Cases

First, install PyYAML:

pip install pyyaml

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🔹 yaml.safe_load() — Load Kubernetes Manifest for Validation

import yaml

with open("deployment.yaml") as f:
    manifest = yaml.safe_load(f)

print("Deployment Name:", manifest["metadata"]["name"])

📌 Use when reading trusted YAML like Kubernetes configs, CI/CD pipelines.

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🔹 yaml.load() — Load with Custom Loader (when required)

import yaml

with open("pipeline.yaml") as f:
    data = yaml.load(f, Loader=yaml.FullLoader)

print("Stages:", data.get("stages"))

⚠️ Use only with Loader=.... Prefer safe_load unless you need custom types.

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🔹 yaml.dump() — Generate Ansible Inventory Dynamically

import yaml

inventory = {
    "all": {
        "hosts": ["web1.example.com", "web2.example.com"],
        "vars": {"ansible_user": "ubuntu"}
    }
}

with open("inventory.yml", "w") as f:
    yaml.dump(inventory, f)

print("Inventory YAML created")

---

🔹 yaml.safe_dump() — Write CI/CD Config Without Tags

import yaml

config = {
    "stages": ["build", "test", "deploy"],
    "build": {"script": "make build"}
}

with open("gitlab-ci.yml", "w") as f:
    yaml.safe_dump(config, f, default_flow_style=False)

print("GitLab CI config written")

✅ Avoids Python object tags like !!python/object.

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🔹 yaml.load_all() — Load Multi-Document YAML (K8s manifest)

import yaml

with open("multi-doc.yaml") as f:
    docs = list(yaml.load_all(f, Loader=yaml.SafeLoader))

for doc in docs:
    print("Loaded kind:", doc.get("kind"))

📄 Example input:

---
kind: Deployment
metadata:
  name: my-app
---
kind: Service
metadata:
  name: my-service

---

🔹 yaml.dump_all() — Generate Multi-Doc K8s File

import yaml

docs = [
    {"kind": "Deployment", "metadata": {"name": "web-app"}},
    {"kind": "Service", "metadata": {"name": "web-service"}}
]

with open("k8s-stack.yaml", "w") as f:
    yaml.dump_all(docs, f)

print("Multi-doc YAML written")

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✅ Summary

Method	Real Use Case Example
yaml.safe_load()	Load Kubernetes YAML safely
yaml.load()	Load full YAML with custom Python types
yaml.dump()	Convert Python to YAML (Ansible inventory)
yaml.safe_dump()	Export CI/CD YAML (safe, clean format)
yaml.load_all()	Read multi-resource Kubernetes YAML file
yaml.dump_all()	Write multiple YAML docs (e.g., full K8s stack)

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