SPARQL Class Instance Counts

This notebook demonstrates basic SPARQL queries against the ClimateKG Wikibase instance to count how many items belong to each major class in the corpus hierarchy.

Wikibase Instance: ClimateKG Production

SPARQL Endpoint: https://prod-climatekg.semanticclimate.org/bigdata/sparql

📓 Download Notebook: class-counts.ipynb - Run this notebook yourself to execute live queries against ClimateKG.

Setup

First, we’ll import the necessary libraries and configure the SPARQL endpoint.

Show code 
from SPARQLWrapper import SPARQLWrapper, JSON
import pandas as pd
from IPython.display import display, Markdown, HTML

# Configure the SPARQL endpoint
SPARQL_ENDPOINT = "https://prod-climatekg.semanticclimate.org/query/proxy/sparql"
WIKIBASE_URL = "https://prod-climatekg.semanticclimate.org"

print("✓ Libraries imported successfully")
print(f"✓ SPARQL Endpoint: {SPARQL_ENDPOINT}")
✓ Libraries imported successfully
✓ SPARQL Endpoint: https://prod-climatekg.semanticclimate.org/query/proxy/sparql

Helper Functions

We’ll create helper functions to execute SPARQL queries and display results.

Show code 
def count_class_instances(class_qid, class_name=""):
    """
    Count the number of items that are instances of a given class.
    Uses P1 (instance of) to find items belonging to the given class QID.
    """
    # Build the SPARQL query using P1 (instance of)
    query = f"""PREFIX wd: <{WIKIBASE_URL}/entity/>
PREFIX wdt: <{WIKIBASE_URL}/prop/direct/>

SELECT (COUNT(?item) AS ?count) WHERE {{
  ?item wdt:P1 wd:{class_qid} .
}}"""

    # Execute the query
    sparql = SPARQLWrapper(SPARQL_ENDPOINT)
    sparql.setQuery(query)
    sparql.setReturnFormat(JSON)

    try:
        results = sparql.query().convert()
        count = int(results["results"]["bindings"][0]["count"]["value"])

        # Generate query URL for Wikibase SPARQL interface
        import urllib.parse
        query_url = f"{WIKIBASE_URL}/query/#" + urllib.parse.quote(query)

        return {
            "class_qid": class_qid,
            "class_name": class_name,
            "count": count,
            "query": query,
            "query_url": query_url,
            "entity_url": f"{WIKIBASE_URL}/wiki/Item:{class_qid}"
        }
    except Exception as e:
        print(f"Error querying {class_qid}: {e}")
        return {
            "class_qid": class_qid,
            "class_name": class_name,
            "count": 0,
            "query": query,
            "error": str(e)
        }

def display_count_result(result):
    """
    Display the count result in a formatted way.
    """
    class_label = f"{result['class_name']} ({result['class_qid']})" if result['class_name'] else result['class_qid']

    display(Markdown(f"### {class_label}"))

    if 'error' in result:
        display(HTML(f'<p style="color: red;">&#10060; Error: {result["error"]}</p>'))
        return

    # Display count
    display(HTML(f'<p style="font-size: 1.5em; font-weight: bold; color: #2c3e50;">Count: {result["count"]:,} items</p>'))

    # Display links
    display(HTML(f'''
    <p>
        <a href="{result['entity_url']}" target="_blank" style="margin-right: 15px;">View Class in Wikibase</a>
        <a href="{result['query_url']}" target="_blank">Run Query in SPARQL Interface</a>
    </p>
    '''))

    # Display SPARQL query
    display(Markdown("**SPARQL Query:**"))
    display(HTML(f'<pre style="background-color: #f4f4f4; padding: 10px; border-radius: 5px; overflow-x: auto;"><code>{result["query"]}</code></pre>'))

    display(HTML('<hr style="margin: 30px 0;">'))

print("✓ Helper functions defined")
✓ Helper functions defined

Class Instance Counts

The following sections show the count of items for each major class in the corpus hierarchy. Each count is accompanied by:

  • The SPARQL query used to obtain the count
  • A link to view the class definition in Wikibase
  • A link to run the query in the Wikibase SPARQL interface

Corpus Hierarchy Classes

The classes are counted in the following order, representing the typical hierarchy of IPCC corpus items:

  • Q2: Work (abstract creation — the base class for all works)
  • Q3: Report Series (a series of individual monograph standalone works)
  • Q4: Report (a standalone written work — book/monograph/volume)
  • Q5: Text Division (manuscript hierarchical component)
  • Q1: Category (subject or topic tag)
  • Q2087: Acronym (IPCC AR6 acronym)
  • Q3998: Author (IPCC AR6 author — person)

Q2 - Work

Show code 
result_q2 = count_class_instances("Q2", "Work")
display_count_result(result_q2)

Work (Q2)

Count: 0 items

View Class in Wikibase Run Query in SPARQL Interface

SPARQL Query:

PREFIX wd: 
PREFIX wdt: 

SELECT (COUNT(?item) AS ?count) WHERE {
  ?item wdt:P1 wd:Q2 .
}

Q3 - Report Series

Show code 
result_q3 = count_class_instances("Q3", "Report Series")
display_count_result(result_q3)

Report Series (Q3)

Count: 1 items

View Class in Wikibase Run Query in SPARQL Interface

SPARQL Query:

PREFIX wd: 
PREFIX wdt: 

SELECT (COUNT(?item) AS ?count) WHERE {
  ?item wdt:P1 wd:Q3 .
}

Q4 - Report

Show code 
result_q4 = count_class_instances("Q4", "Report")
display_count_result(result_q4)

Report (Q4)

Count: 7 items

View Class in Wikibase Run Query in SPARQL Interface

SPARQL Query:

PREFIX wd: 
PREFIX wdt: 

SELECT (COUNT(?item) AS ?count) WHERE {
  ?item wdt:P1 wd:Q4 .
}

Q5 - Text Division

Show code 
result_q5 = count_class_instances("Q5", "Text Division")
display_count_result(result_q5)

Text Division (Q5)

Count: 10 items

View Class in Wikibase Run Query in SPARQL Interface

SPARQL Query:

PREFIX wd: 
PREFIX wdt: 

SELECT (COUNT(?item) AS ?count) WHERE {
  ?item wdt:P1 wd:Q5 .
}

Q1 - Category

Show code 
result_q1 = count_class_instances("Q1", "Category")
display_count_result(result_q1)

Category (Q1)

Count: 1,001 items

View Class in Wikibase Run Query in SPARQL Interface

SPARQL Query:

PREFIX wd: 
PREFIX wdt: 

SELECT (COUNT(?item) AS ?count) WHERE {
  ?item wdt:P1 wd:Q1 .
}

Q2087 - Acronym

Show code 
result_q2087 = count_class_instances("Q2087", "Acronym")
display_count_result(result_q2087)

Acronym (Q2087)

Count: 1,910 items

View Class in Wikibase Run Query in SPARQL Interface

SPARQL Query:

PREFIX wd: 
PREFIX wdt: 

SELECT (COUNT(?item) AS ?count) WHERE {
  ?item wdt:P1 wd:Q2087 .
}

Q3998 - Author

Show code 
result_q3998 = count_class_instances("Q3998", "Author")
display_count_result(result_q3998)

Author (Q3998)

Count: 932 items

View Class in Wikibase Run Query in SPARQL Interface

SPARQL Query:

PREFIX wd: 
PREFIX wdt: 

SELECT (COUNT(?item) AS ?count) WHERE {
  ?item wdt:P1 wd:Q3998 .
}

Summary Table

Here’s a summary of all the class counts:

Show code 
# Collect all results
all_results = [result_q2, result_q3, result_q4, result_q5, result_q1, result_q2087, result_q3998]

# Create summary DataFrame
summary_data = []
for result in all_results:
    if 'error' not in result:
        summary_data.append({
            'Class': result['class_qid'],
            'Name': result['class_name'],
            'Count': result['count']
        })

summary_df = pd.DataFrame(summary_data, columns=['Class', 'Name', 'Count'])

# Display as formatted table
display(Markdown("### Instance Counts by Class"))
if not summary_df.empty:
    display(summary_df.style.format({'Count': '{:,}'}).set_properties(**{
        'text-align': 'left',
        'font-size': '1.1em'
    }))
    print(f"\n✓ Total items counted: {summary_df['Count'].sum():,}")

else:    print("No results available — run the query cells above first.")

Instance Counts by Class

  Class Name Count
0 Q2 Work 0
1 Q3 Report Series 1
2 Q4 Report 7
3 Q5 Text Division 10
4 Q1 Category 1,001
5 Q2087 Acronym 1,910
6 Q3998 Author 932 

✓ Total items counted: 3,861

Understanding the Queries

SPARQL Query Structure

All the queries above follow the same basic pattern:

PREFIX wd: <https://prod-climatekg.semanticclimate.org/entity/>
PREFIX wdt: <https://prod-climatekg.semanticclimate.org/prop/direct/>

SELECT (COUNT(?item) AS ?count) WHERE {
  ?item wdt:P1 wd:QX .
}

Explanation: - PREFIX wd: - Defines the namespace for entities (classes and items) - PREFIX wdt: - Defines the namespace for direct properties - ?item wdt:P1 wd:QX - Finds all items (?item) that have property P1 (instance of) pointing to class QX - COUNT(?item) - Counts the number of matching items

Key Property

  • P1: “instance of” — This property links items to their class in ClimateKG

Running Your Own Queries

You can run these queries directly in the ClimateKG SPARQL Query Service or use the links provided above for each class.

Next Steps

This notebook demonstrates basic instance counting. You can extend these queries to:

  • Filter by additional properties
  • Retrieve actual item labels and data
  • Perform aggregations and statistics
  • Explore relationships between classes

Related Notebooks: - View this notebook on GitHub

External Resources: - ClimateKG Wikibase - SPARQL Query Service - Wikibase SPARQL Documentation