🕵️ Your First Anonymization¶

Detect sensitive entities and replace them with LLM-generated substitutes -- the simplest end-to-end example of Anonymizer.

📚 What you'll learn¶

• Load a CSV dataset and configure Anonymizer in a few lines
• Preview anonymized results on a small sample before committing to a full run
• Inspect entity detection and replacement with display_record()
• Process the full dataset with run()

Tip: First time running notebooks? Start with setup instructions.

⚙️ Setup¶

• Check if your NVIDIA_API_KEY from build.nvidia.com is registered for model access.
• Import the core Anonymizer classes: Anonymizer, AnonymizerConfig, AnonymizerInput, and Substitute.
• Anonymizer() initializes with the default model provider -- no extra config needed.

In [2]:

import getpass
import os

if not os.getenv("NVIDIA_API_KEY"):
    key = getpass.getpass("Enter NVIDIA_API_KEY from build.nvidia.com: ").strip()
    if not key:
        raise RuntimeError("NVIDIA_API_KEY is required to run these notebooks.")
    os.environ["NVIDIA_API_KEY"] = key

import getpass import os if not os.getenv("NVIDIA_API_KEY"): key = getpass.getpass("Enter NVIDIA_API_KEY from build.nvidia.com: ").strip() if not key: raise RuntimeError("NVIDIA_API_KEY is required to run these notebooks.") os.environ["NVIDIA_API_KEY"] = key

In [3]:

from anonymizer import Anonymizer, AnonymizerConfig, AnonymizerInput, Substitute

from anonymizer import Anonymizer, AnonymizerConfig, AnonymizerInput, Substitute

In [4]:

anonymizer = Anonymizer()

anonymizer = Anonymizer()

[13:31:16] [INFO] 🔧 Anonymizer initialized with 3 model configs

[13:31:16] [INFO]   |-- 🔎 detector:  gliner-pii-detector

[13:31:16] [INFO]   |-- ✅ validator: gpt-oss-120b

[13:31:16] [INFO]   |-- 🧩 augmenter: gpt-oss-120b

📦 Load data and configure¶

• AnonymizerInput points to your CSV and names the text column. data_summary gives the LLM context about the kind of text it will process.
• Records up to 2,000 tokens each work with the default model configs.
• AnonymizerConfig with Substitute() tells Anonymizer to replace detected entities with LLM-generated synthetic values for names, cities, dates, etc.

In [5]:

input_data = AnonymizerInput(
    source="https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv",
    text_column="biography",
    data_summary="Biographical profiles of individuals",
)

config = AnonymizerConfig(replace=Substitute())

input_data = AnonymizerInput( source="https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv", text_column="biography", data_summary="Biographical profiles of individuals", ) config = AnonymizerConfig(replace=Substitute())

👁️ Preview¶

• preview() runs on a small sample so you can iterate quickly.
• Always preview before processing the full dataset -- it's the fastest way to catch prompt or config issues early.

In [6]:

preview = anonymizer.preview(config=config, data=input_data, num_records=3)

preview = anonymizer.preview(config=config, data=input_data, num_records=3)

[13:31:16] [INFO] 📂 Loaded 25 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:31:16] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:31:16] [INFO]   |-- 👀 Preview mode: processing 3 of 25 records

[13:31:16] [INFO] 🔍 Running entity detection on 3 records

[13:32:00] [INFO]   |-- 📋 Detection complete — 78 entities found across 3 records (0 failed) [44.7s]

[13:32:00] [INFO]   |-- labels: first_name=22, organization_name=7, age=5, occupation=5, city=4, state=4, degree=4, university=4, field_of_study=4, last_name=3, race_ethnicity=3, political_view=3, language=2, religious_belief=2, street_address=2, place_name=1, date_of_birth=1, project_name=1, employment_status=1

[13:32:00] [INFO] 🔄 Running Substitute replacement

[13:32:20] [INFO]   |-- 📋 Replacement complete (0 failed) [19.8s]

[13:32:20] [INFO] 🎉 Pipeline complete — 3 records processed, 0 total failures

🔍 Inspect¶

• display_record() shows the original text with highlighted entities, the replacement map, and the anonymized output -- all in one view.
• The result dataframe has original and substituted text side-by-side.

In [7]:

preview.display_record(0)

preview.display_record(0)

Anonymizer Preview (record 0)

Original

Bobby| first_name Watford| last_name, a 40| age‑year‑old Mexican| race_ethnicity veterinarian| occupation living in Denver| city, Colorado| state, grew up on the outskirts of the city and developed a love for animals early on. After graduating from Jefferson High| organization_name, he earned his DVM| degree at the University of Colorado Boulder| university, where he also completed a research stint in wildlife health| field_of_study. Fluent in English| language, Bobby| first_name has always described his upbringing as a blend of small‑town curiosity and the vibrant culture of his community, values that continue to shape his compassionate approach to animal care. Since finishing his training, Bobby| first_name has worked at VCA Animal Hospital| organization_name and later at the Colorado Veterinary Clinic| organization_name, where he now leads a busy mixed‑practice team. He identifies as a Christian Democrat| political_view and often volunteers at local shelters, a habit encouraged by his wife, Maya| first_name, and their two teenage children, Aria and Leo| first_name. Outside the clinic, Bobby| first_name enjoys hiking the Rockies| place_name with his family and mentoring veterinary students from his alma mater.

Replaced

Ethan| first_name Kline| last_name, a 45| age‑year‑old Vietnamese| race_ethnicity wildlife rehabilitator| occupation living in Portland| city, Oregon| state, grew up on the outskirts of the city and developed a love for animals early on. After graduating from Lincoln Academy| organization_name, he earned his DDS| degree at the University of Washington Seattle| university, where he also completed a research stint in environmental epidemiology| field_of_study. Fluent in German| language, Ethan| first_name has always described his upbringing as a blend of small‑town curiosity and the vibrant culture of his community, values that continue to shape his compassionate approach to animal care. Since finishing his training, Ethan| first_name has worked at Paws & Claws Veterinary Hospital| organization_name and later at the Cascade Veterinary Center| organization_name, where he now leads a busy mixed‑practice team. He identifies as a Libertarian| political_view and often volunteers at local shelters, a habit encouraged by his wife, Leila| first_name, and their two teenage children, Mia and Noah| first_name. Outside the clinic, Ethan| first_name enjoys hiking the Sierra Nevada| place_name with his family and mentoring veterinary students from his alma mater.

Replacement Map

Original	Label	Replacement
40	age	45
Aria and Leo	first_name	Mia and Noah
Bobby	first_name	Ethan
Christian Democrat	political_view	Libertarian
Colorado	state	Oregon
Colorado Veterinary Clinic	organization_name	Cascade Veterinary Center
DVM	degree	DDS
Denver	city	Portland
English	language	German
Jefferson High	organization_name	Lincoln Academy
Maya	first_name	Leila
Mexican	race_ethnicity	Vietnamese
Rockies	place_name	Sierra Nevada
University of Colorado Boulder	university	University of Washington Seattle
VCA Animal Hospital	organization_name	Paws & Claws Veterinary Hospital
Watford	last_name	Kline
veterinarian	occupation	wildlife rehabilitator
wildlife health	field_of_study	environmental epidemiology

In [8]:

preview.display_record(1)

preview.display_record(1)

Anonymizer Preview (record 1)

Original

Idilio| first_name Bell| last_name is a 37| age‑year‑old astronomer| occupation living in Edison| city, New Jersey| state. Born on November 21, 1988| date_of_birth, he grew up in a bilingual Italian| race_ethnicity household and speaks English| language at home and work. He earned his bachelor’s degree| degree in physics| field_of_study from the University of New Jersey| university and later completed a PhD| degree in astrophysics| field_of_study at Princeton| university, where his dissertation focused on exoplanet atmospheres. After graduation he spent three years at NASA’s Goddard Space Flight Center| organization_name before joining SpaceX| organization_name’s research division, where he now leads a team analyzing data from the Starlink telescope array| project_name. Idilio| first_name describes himself as secular| religious_belief and leans progressive| political_view on most political issues, often volunteering for science outreach programs in his community. Outside the lab, Idilio| first_name shares a modest house on West Roberts Drive| street_address with his wife, Maya| first_name, and their two young daughters, Lina| first_name and Zara| first_name. His mother, Elena| first_name, lives nearby and still cooks the family’s favorite pasta on Sundays, while his father, Marco| first_name, retired| employment_status from an engineering firm in New York| state. Family gatherings are a mix of lively conversation and stargazing sessions on the backyard deck, where Idilio| first_name points out constellations and tells stories of the cosmos that inspire his children’s curiosity.

Replaced

Santiago| first_name Kumar| last_name is a 42| age‑year‑old planetary scientist| occupation living in Boulder| city, Colorado| state. Born on April 12, 1984| date_of_birth, he grew up in a bilingual Greek| race_ethnicity household and speaks Spanish| language at home and work. He earned his Bachelor of Arts| degree in chemical engineering| field_of_study from the University of Colorado| university and later completed a Doctor of Engineering| degree in marine biology| field_of_study at Stanford University| university, where his dissertation focused on exoplanet atmospheres. After graduation he spent three years at European Space Agency’s European Space Research and Technology Centre| organization_name before joining Blue Origin| organization_name’s research division, where he now leads a team analyzing data from the Aurora satellite constellation| project_name. Santiago| first_name describes himself as agnostic| religious_belief and leans moderate| political_view on most political issues, often volunteering for science outreach programs in his community. Outside the lab, Santiago| first_name shares a modest house on East Monroe Avenue| street_address with his wife, Priya| first_name, and their two young daughters, Aisha| first_name and Nadia| first_name. His mother, Sofia| first_name, lives nearby and still cooks the family’s favorite pasta on Sundays, while his father, Victor| first_name, consultant| employment_status from an engineering firm in Illinois| state. Family gatherings are a mix of lively conversation and stargazing sessions on the backyard deck, where Santiago| first_name points out constellations and tells stories of the cosmos that inspire his children’s curiosity.

Replacement Map

Original	Label	Replacement
37	age	42
Bell	last_name	Kumar
Edison	city	Boulder
Elena	first_name	Sofia
English	language	Spanish
Idilio	first_name	Santiago
Italian	race_ethnicity	Greek
Lina	first_name	Aisha
Marco	first_name	Victor
Maya	first_name	Priya
NASA’s Goddard Space Flight Center	organization_name	European Space Agency’s European Space Research and Technology Centre
New Jersey	state	Colorado
New York	state	Illinois
November 21, 1988	date_of_birth	April 12, 1984
PhD	degree	Doctor of Engineering
Princeton	university	Stanford University
SpaceX	organization_name	Blue Origin
Starlink telescope array	project_name	Aurora satellite constellation
University of New Jersey	university	University of Colorado
West Roberts Drive	street_address	East Monroe Avenue
Zara	first_name	Nadia
astronomer	occupation	planetary scientist
bachelor’s degree	degree	Bachelor of Arts
in astrophysics	field_of_study	in marine biology
physics	field_of_study	chemical engineering
progressive	political_view	moderate
retired	employment_status	consultant
secular	religious_belief	agnostic

In [9]:

preview.dataframe

preview.dataframe

Out[9]:

	biography	biography_with_spans	final_entities	biography_replaced
0	Bobby Watford, a 40‑year‑old Mexican veterinar...	<first_name>Bobby</first_name> <last_name>Watf...	{'entities': [{'end_position': 5, 'id': 'first...	Ethan Kline, a 45‑year‑old Vietnamese wildlife...
1	Idilio Bell is a 37‑year‑old astronomer living...	<first_name>Idilio</first_name> <last_name>Bel...	{'entities': [{'end_position': 6, 'id': 'first...	Santiago Kumar is a 42‑year‑old planetary scie...
2	Jodi Allison, 36, lives at 204 Bluegrass in Cl...	<first_name>Jodi</first_name> <last_name>Allis...	{'entities': [{'end_position': 4, 'id': 'first...	Leah Keller, 42, lives at 317 Maplewood in Ale...

🚀 Full run¶

• run() processes the entire dataset with the same config you previewed.
• Access the output via result.dataframe.

In [10]:

result = anonymizer.run(config=config, data=input_data)
print(result)

result = anonymizer.run(config=config, data=input_data) print(result)

[13:32:20] [INFO] 📂 Loaded 25 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:32:20] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:32:20] [INFO] 🔍 Running entity detection on 25 records

[13:37:23] [INFO]   |-- 📋 Detection complete — 666 entities found across 25 records (0 failed) [303.2s]

[13:37:23] [INFO]   |-- labels: first_name=154, organization_name=62, occupation=47, city=41, university=36, field_of_study=34, race_ethnicity=30, last_name=27, state=27, age=26, degree=25, political_view=25, religious_belief=25, street_address=23, language=19, place_name=15, employment_status=11, county=11, date_of_birth=9, education_level=7, date=5, company_name=4, country=1, gender=1, postcode=1

[13:37:23] [INFO] 🔄 Running Substitute replacement

/Users/lramaswamy/Documents/github/Anonymizer/src/anonymizer/engine/row_partitioning.py:42: FutureWarning: The behavior of DataFrame concatenation with empty or all-NA entries is deprecated. In a future version, this will no longer exclude empty or all-NA columns when determining the result dtypes. To retain the old behavior, exclude the relevant entries before the concat operation.
  pd.concat(list(parts), ignore_index=True)
[13:39:33] [INFO]   |-- 📋 Replacement complete (0 failed) [129.3s]

[13:39:33] [INFO] 🎉 Pipeline complete — 25 records processed, 0 total failures

AnonymizerResult(rows=25, columns=4, trace_columns=21, failed_records=0)

In [11]:

result.dataframe.head()

result.dataframe.head()

Out[11]:

	biography	biography_with_spans	final_entities	biography_replaced
0	Bobby Watford, a 40‑year‑old Mexican veterinar...	<first_name>Bobby</first_name> <last_name>Watf...	{'entities': array([{'end_position': 5, 'id': ...	Ethan Hawthorne, a 45‑year‑old Vietnamese mari...
1	Idilio Bell is a 37‑year‑old astronomer living...	<first_name>Idilio</first_name> <last_name>Bel...	{'entities': array([{'end_position': 6, 'id': ...	Mateo Kline is a 36‑year‑old geophysicist livi...
2	Jodi Allison, 36, lives at 204 Bluegrass in Cl...	<first_name>Jodi</first_name> <last_name>Allis...	{'entities': array([{'end_position': 4, 'id': ...	Leah Harper, 42, lives at 312 Magnolia in Sava...
3	James Mills is a 69‑year‑old paramedic who liv...	<first_name>James</first_name> <last_name>Mill...	{'entities': array([{'end_position': 5, 'id': ...	Robert Harper is a 71‑year‑old firefighter who...
4	Nancy Burton is a 21‑year‑old cashier who live...	<first_name>Nancy</first_name> <last_name>Burt...	{'entities': array([{'end_position': 5, 'id': ...	Aisha Khan is a 22‑year‑old stock clerk who li...

⏭️ Next steps¶

• 🔍 Inspecting Detected Entities -- dig into what the detection pipeline found and debug quality.
• 🎯 Choosing a Replacement Strategy -- compare Redact, Annotate, Hash, and Substitute side-by-side.
• ✏️ Rewriting Biographies -- generate privacy-safe paraphrases instead of token-level replacements.