docs: add beginner-friendly knowledge graph example

[gourangasatapathyvit]

Summary

• Adds examples/guides/beginner_knowledge_graph.py — a step-by-step example that walks beginners through the full Cognee workflow: remember → explore → recall
• The example ingests a short paragraph about Marie Curie, prints every extracted entity and relationship from the knowledge graph, then asks natural-language questions against it
• Adds an "Understanding the Knowledge Graph" section to the README explaining what a knowledge graph is, what Cognee does under the hood, and showing sample output
• Adds a pointer to the example in the README Examples section

Closes #2738

What the example covers

1. REMEMBER — Feed sample text into Cognee
2. EXPLORE — Retrieve and print all graph nodes (entities) and edges (relationships) using get_graph_engine().get_graph_data(), filtering out internal nodes (DocumentChunk, TextSummary) for clarity
3. RECALL — Ask three natural-language questions and print clean text answers

Changes

• examples/guides/beginner_knowledge_graph.py — new beginner-friendly example with inline explanations of what nodes, edges, and relationships are
• README.md — new "Understanding the Knowledge Graph" section with sample output; pointer in Examples section

Test plan

• Ran python examples/guides/beginner_knowledge_graph.py end-to-end with Azure OpenAI — all 3 stages complete successfully
• Verified entities (21 nodes) and relationships (33 edges) are extracted and displayed cleanly
• Verified all 3 recall questions answered correctly
• ruff check and ruff format --check pass
• markdownlint MD040 resolved (language tag on fenced code block)

I affirm that all code in every commit of this pull request conforms to the terms of the Topoteretes Developer Certificate of Origin

🤖 Generated with Claude Code

Summary by CodeRabbit

• Documentation
  • Added an "Understanding the Knowledge Graph" section explaining knowledge graphs, the product's end-to-end workflow, and a sample output with run instructions.
  • Added a "New to knowledge graphs?" callout linking to a beginner-friendly example and showing how to execute it.
• New Features
  • Added a runnable beginner example demonstrating ingestion, entity/relationship extraction, and natural‑language querying.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 09e6eb00-d09a-40c9-9f5b-4016b5584e2d

📥 Commits

Reviewing files that changed from the base of the PR and between 1342d0f and 23c27b6.

📒 Files selected for processing (2)

• README.md
• examples/guides/beginner_knowledge_graph.py

✅ Files skipped from review due to trivial changes (1)

• README.md

🚧 Files skipped from review as they are similar to previous changes (1)

• examples/guides/beginner_knowledge_graph.py

---

Walkthrough

This PR adds a beginner-friendly knowledge graph example: a README section and callout linking to a new runnable script that resets state, ingests sample text, prints extracted graph nodes/edges, and runs predefined natural-language queries.

Changes

Beginner Knowledge Graph Example

Layer / File(s)	Summary
README knowledge-graph documentation README.md	Adds an "Understanding the Knowledge Graph" section describing the graph workflow, a sample output block, and a python examples/guides/beginner_knowledge_graph.py run command; also inserts a "New to knowledge graphs?" callout linking to the example.
Example script docstring, imports, and sample text examples/guides/beginner_knowledge_graph.py	Module docstring describing REMEMBER/EXPLORE/RECALL workflow, required imports, and the SAMPLE_TEXT constant used as the demo input.
Async main workflow (reset, ingest, extract, query) and entry point examples/guides/beginner_knowledge_graph.py	Implements async def main() with Stage 0: cognee.forget(everything=True), Stage 1: cognee.remember(...) ingest, Stage 2: get_graph_data() to retrieve and print entities and relationships, Stage 3: looping cognee.recall(question) to print answers, a final summary, and if __name__ == "__main__": asyncio.run(main()) entry point.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main change: adding a beginner-friendly knowledge graph example, which directly aligns with the PR's primary objective.
Description check	✅ Passed	The description provides a clear summary of changes, explicitly links the related issue (#2738), outlines what the example covers, lists concrete changes, and includes a detailed test plan with verification steps.
Linked Issues check	✅ Passed	The PR successfully addresses all coding requirements from issue #2738: provides a simple beginner-friendly example demonstrating the full Cognee workflow (remember → explore → recall), shows how a knowledge graph is created from input, demonstrates output interpretation with plain-language guidance, and adds README entry points for discoverability.
Out of Scope Changes check	✅ Passed	All changes are in scope: the new beginner_knowledge_graph.py example directly addresses the linked issue, and README updates document the example and explain knowledge graph concepts as intended.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (1)

examples/guides/beginner_knowledge_graph.py (1)

40-40: ⚡ Quick win

Consider adding a comment about the internal API usage.

The import of get_graph_engine() from cognee.infrastructure.databases.graph is an internal API that may change in future versions. While this is intentional for the demonstration (per the PR objectives), consider adding a comment explaining that this is an advanced inspection technique for educational purposes.

📝 Suggested comment addition

 import asyncio
 import cognee
+# Note: get_graph_engine is an internal API used here for educational purposes
+# to show graph internals. For production code, use cognee.recall() instead.
 from cognee.infrastructure.databases.graph import get_graph_engine

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@examples/guides/beginner_knowledge_graph.py` at line 40, The import of
get_graph_engine from cognee.infrastructure.databases.graph uses an internal API
that may change; update the file to add a short inline comment above the import
(near the get_graph_engine import statement) stating that this is an
internal/advanced inspection technique used for demonstration and may break
across versions, and recommend using the public API for production code or
pinning the library version when relying on it.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@examples/guides/beginner_knowledge_graph.py`:
- Line 58: Add a short docstring to the async function main() that briefly
summarizes what the function demonstrates (e.g., initializing the knowledge
graph, creating nodes/edges, and showing query usage); place the docstring
immediately below the async def main(): line so the function is documented per
project guidelines.

---

Nitpick comments:
In `@examples/guides/beginner_knowledge_graph.py`:
- Line 40: The import of get_graph_engine from
cognee.infrastructure.databases.graph uses an internal API that may change;
update the file to add a short inline comment above the import (near the
get_graph_engine import statement) stating that this is an internal/advanced
inspection technique used for demonstration and may break across versions, and
recommend using the public API for production code or pinning the library
version when relying on it.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: baf91219-43ce-482e-ba85-fc815d92677c

📥 Commits

Reviewing files that changed from the base of the PR and between 66f8f1f and 6349b7d.

📒 Files selected for processing (2)

• README.md
• examples/guides/beginner_knowledge_graph.py

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@README.md`:
- Line 194: The README contains a fenced code block opened with triple backticks
that lacks a language tag which triggers markdownlint MD040; update the opening
fence to include a language specifier (e.g., change ``` to ```text) so the block
is properly tagged and lint-clean, leaving the block contents unchanged and
retaining the closing triple backticks.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 592e777e-43b6-4332-a533-f5737067ad0b

📥 Commits

Reviewing files that changed from the base of the PR and between 6349b7d and abe7019.

📒 Files selected for processing (2)

• README.md
• examples/guides/beginner_knowledge_graph.py

🚧 Files skipped from review as they are similar to previous changes (1)

• examples/guides/beginner_knowledge_graph.py

[gourangasatapathyvit]

hi @Vasilije1990 , Can you pls review the PR