🕵️ Choosing a Replacement Strategy¶

Four replace mode strategies compared side-by-side on the same data.

Strategy	What it does
Substitute	LLM-generated contextual replacements
Redact	Label-based markers ([REDACTED_FIRST_NAME])
Annotate	Tags entities but keeps original text
Hash	Deterministic hash digest

📚 What you'll learn¶

• Compare Redact, Annotate, Hash, and Substitute on the same input
• Customize output formats with format_template
• Understand which strategy fits your use case (readability, determinism, privacy)

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.
  • The default build.nvidia.com (NVIDIA Build) setup is a convenient way to try Anonymizer and iterate on previews. Use of NVIDIA Build is subject to NVIDIA Build's own terms of service and privacy practices, which are separate from and independent of the NeMo Framework library. NVIDIA Build is intended for evaluation and testing purposes only and may not be used in production environments. Do not upload any confidential information or personal data when using NVIDIA Build. Your use of NVIDIA Build is logged for security purposes and to improve NVIDIA products and services.
  • Request and token rate limits on build.nvidia.com vary by account and model access, and lower-volume development access can be slow for full-dataset runs. Start with preview() on a small sample, then move to your own endpoint for production data and usage.
• Import all four strategy classes: Redact, Annotate, Hash, Substitute.
• Anonymizer() initializes with the default model provider -- no extra config needed.
• configure_logging(LoggingConfig.default()) keeps logs at INFO. Switch to LoggingConfig.debug() when troubleshooting.

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 [ ]:

from anonymizer import (
    Annotate,
    Anonymizer,
    AnonymizerConfig,
    AnonymizerInput,
    Hash,
    LoggingConfig,
    Redact,
    Substitute,
    configure_logging,
)

configure_logging(LoggingConfig.default())

from anonymizer import ( Annotate, Anonymizer, AnonymizerConfig, AnonymizerInput, Hash, LoggingConfig, Redact, Substitute, configure_logging, ) configure_logging(LoggingConfig.default())

In [4]:

anonymizer = Anonymizer()

anonymizer = Anonymizer()

[13:17:15] [INFO] 🔧 Anonymizer initialized with 3 model configs

[13:17:15] [INFO]   |-- 🔎 detector:  gliner-pii-detector

[13:17:15] [INFO]   |-- ✅ validator: gpt-oss-120b

[13:17:15] [INFO]   |-- 🧩 augmenter: gpt-oss-120b

📦 Input data¶

• We use the same biographies dataset throughout so each strategy is compared on identical input.

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",
)

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", )

🔄 Substitute¶

• Uses an LLM to generate contextually appropriate synthetic replacements.
  • The LLM considers the full document context matching names with emails, cities to states, etc.
• Customize with instructions to steer the LLM's replacement choices.

In [6]:

substitute_config = AnonymizerConfig(replace=Substitute())

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

substitute_config = AnonymizerConfig(replace=Substitute()) substitute_preview = anonymizer.preview( config=substitute_config, data=input_data, num_records=3, )

[13:17:15] [INFO] 👀 Preview mode: 📂 Loaded 3 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:17:15] [INFO] 🔍 Running entity detection on 3 records

[13:17:15] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:17:36] [INFO]   |-- 📋 Detection complete — 76 entities found across 3 records (0 failed) [20.6s]

[13:17:36] [INFO]   |-- labels: first_name=22, state=6, age=5, occupation=5, city=5, company_name=4, last_name=3, race_ethnicity=3, organization_name=3, language=3, political_view=3, education_level=3, field_of_study=2, street_address=2, degree=1, university=1, place_name=1, date_of_birth=1, project_name=1, employment_status=1, religious_belief=1

[13:17:36] [INFO] 🔄 Running Substitute replacement

[13:17:50] [INFO]   |-- 📋 Replacement complete (0 failed) [14.6s]

[13:17:50] [INFO] 🎉 Pipeline complete — 3 records processed, 0 total failures

In [7]:

substitute_preview.display_record(0)

substitute_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| company_name and later at the Colorado Veterinary Clinic| company_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 Hernandez| last_name, a 52| age‑year‑old Filipino| race_ethnicity zoologist| 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 High| organization_name, he earned his Master of Science| degree at the University of Washington| university, where he also completed a research stint in conservation genetics| field_of_study. Fluent in Spanish| 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 PetCare Veterinary Center| company_name and later at the Cascade Animal Hospital| company_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, Nina| first_name, and their two teenage children, Sofia and Mateo| 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	52
Aria and Leo	first_name	Sofia and Mateo
Bobby	first_name	Ethan
Christian Democrat	political_view	Libertarian
Colorado	state	Oregon
Colorado Veterinary Clinic	company_name	Cascade Animal Hospital
DVM	degree	Master of Science
Denver	city	Portland
English	language	Spanish
Jefferson High	organization_name	Lincoln High
Maya	first_name	Nina
Mexican	race_ethnicity	Filipino
Rockies	place_name	Sierra Nevada
University of Colorado Boulder	university	University of Washington
VCA Animal Hospital	company_name	PetCare Veterinary Center
Watford	last_name	Hernandez
veterinarian	occupation	zoologist
wildlife health	field_of_study	conservation genetics

Custom instructions¶

• Pass instructions to guide the LLM -- e.g. keep replacements within a specific region, culture, or naming convention.

In [8]:

substitute_custom_config = AnonymizerConfig(
    replace=Substitute(instructions="Use only Japanese names and locations for all replacements.")
)
substitute_custom_preview = anonymizer.preview(
    config=substitute_custom_config,
    data=input_data,
    num_records=3,
)
substitute_custom_preview.display_record(0)

substitute_custom_config = AnonymizerConfig( replace=Substitute(instructions="Use only Japanese names and locations for all replacements.") ) substitute_custom_preview = anonymizer.preview( config=substitute_custom_config, data=input_data, num_records=3, ) substitute_custom_preview.display_record(0)

[13:17:51] [INFO] 👀 Preview mode: 📂 Loaded 3 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:17:51] [INFO] 🔍 Running entity detection on 3 records

[13:17:51] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:18:18] [INFO]   |-- 📋 Detection complete — 78 entities found across 3 records (0 failed) [27.1s]

[13:18:18] [INFO]   |-- labels: first_name=22, state=6, age=5, occupation=5, city=5, organization_name=5, company_name=4, last_name=3, race_ethnicity=3, language=3, political_view=3, degree=2, field_of_study=2, education_level=2, religious_belief=2, street_address=2, university=1, date_of_birth=1, telescope_array=1, employment_status=1

[13:18:18] [INFO] 🔄 Running Substitute replacement

[13:18:28] [INFO]   |-- 📋 Replacement complete (0 failed) [10.2s]

[13:18:28] [INFO] 🎉 Pipeline complete — 3 records processed, 0 total failures

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| company_name and later at the Colorado Veterinary Clinic| company_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 with his family and mentoring veterinary students from his alma mater.

Replaced

Takumi| first_name Tanaka| last_name, a 45| age‑year‑old Japanese| race_ethnicity marine biologist| occupation living in Sapporo| city, Hokkaido| state, grew up on the outskirts of the city and developed a love for animals early on. After graduating from Tokyo Metropolitan Hibiya High School| organization_name, he earned his Ph.D. in Marine Biology| degree at the University of Tokyo| university, where he also completed a research stint in marine ecology| field_of_study. Fluent in Japanese| language, Takumi| 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, Takumi| first_name has worked at Sakura Animal Clinic| company_name and later at the Nihon Veterinary Center| company_name, where he now leads a busy mixed‑practice team. He identifies as a Liberal Democratic Party| political_view and often volunteers at local shelters, a habit encouraged by his wife, Haruka| first_name, and their two teenage children, Sora and Ren| first_name. Outside the clinic, Takumi| first_name enjoys hiking the Rockies with his family and mentoring veterinary students from his alma mater.

Replacement Map

Original	Label	Replacement
40	age	45
Aria and Leo	first_name	Sora and Ren
Bobby	first_name	Takumi
Christian Democrat	political_view	Liberal Democratic Party
Colorado	state	Hokkaido
Colorado Veterinary Clinic	company_name	Nihon Veterinary Center
DVM	degree	Ph.D. in Marine Biology
Denver	city	Sapporo
English	language	Japanese
Jefferson High	organization_name	Tokyo Metropolitan Hibiya High School
Maya	first_name	Haruka
Mexican	race_ethnicity	Japanese
University of Colorado Boulder	university	University of Tokyo
VCA Animal Hospital	company_name	Sakura Animal Clinic
Watford	last_name	Tanaka
veterinarian	occupation	marine biologist
wildlife health	field_of_study	marine ecology

🚫 Redact¶

• Replaces each entity with a label-based marker. Default: [REDACTED_FIRST_NAME].
• Customize with Redact(format_template=...).

In [9]:

redact_config = AnonymizerConfig(replace=Redact())

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

redact_preview.display_record(0)

redact_config = AnonymizerConfig(replace=Redact()) redact_preview = anonymizer.preview( config=redact_config, data=input_data, num_records=3, ) redact_preview.display_record(0)

[13:18:28] [INFO] 👀 Preview mode: 📂 Loaded 3 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:18:28] [INFO] 🔍 Running entity detection on 3 records

[13:18:28] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:18:54] [INFO]   |-- 📋 Detection complete — 75 entities found across 3 records (0 failed) [25.6s]

[13:18:54] [INFO]   |-- labels: first_name=22, state=6, age=5, occupation=5, city=5, organization_name=4, education_level=4, last_name=3, race_ethnicity=3, language=3, company_name=3, political_view=3, religious_belief=2, street_address=2, university=1, place_name=1, date_of_birth=1, field_of_study=1, employment_status=1

[13:18:54] [INFO] 🔄 Running Redact replacement

[13:18:54] [INFO]   |-- 📋 Replacement complete (0 failed) [0.0s]

[13:18:54] [INFO] 🎉 Pipeline complete — 3 records processed, 0 total failures

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| education_level at the University of Colorado Boulder| university, where he also completed a research stint in wildlife health. 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| company_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

[REDACTED_FIRST_NAME]| first_name [REDACTED_LAST_NAME]| last_name, a [REDACTED_AGE]| age‑year‑old [REDACTED_RACE_ETHNICITY]| race_ethnicity [REDACTED_OCCUPATION]| occupation living in [REDACTED_CITY]| city, [REDACTED_STATE]| state, grew up on the outskirts of the city and developed a love for animals early on. After graduating from [REDACTED_ORGANIZATION_NAME]| organization_name, he earned his [REDACTED_EDUCATION_LEVEL]| education_level at the [REDACTED_UNIVERSITY]| university, where he also completed a research stint in wildlife health. Fluent in [REDACTED_LANGUAGE]| language, [REDACTED_FIRST_NAME]| 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, [REDACTED_FIRST_NAME]| first_name has worked at [REDACTED_COMPANY_NAME]| company_name and later at the [REDACTED_ORGANIZATION_NAME]| organization_name, where he now leads a busy mixed‑practice team. He identifies as a [REDACTED_POLITICAL_VIEW]| political_view and often volunteers at local shelters, a habit encouraged by his wife, [REDACTED_FIRST_NAME]| first_name, and their two teenage children, [REDACTED_FIRST_NAME]| first_name. Outside the clinic, [REDACTED_FIRST_NAME]| first_name enjoys hiking the [REDACTED_PLACE_NAME]| place_name with his family and mentoring veterinary students from his alma mater.

Replacement Map

Original	Label	Replacement
Bobby	first_name	[REDACTED_FIRST_NAME]
Watford	last_name	[REDACTED_LAST_NAME]
40	age	[REDACTED_AGE]
Mexican	race_ethnicity	[REDACTED_RACE_ETHNICITY]
veterinarian	occupation	[REDACTED_OCCUPATION]
Denver	city	[REDACTED_CITY]
Colorado	state	[REDACTED_STATE]
Jefferson High	organization_name	[REDACTED_ORGANIZATION_NAME]
DVM	education_level	[REDACTED_EDUCATION_LEVEL]
University of Colorado Boulder	university	[REDACTED_UNIVERSITY]
English	language	[REDACTED_LANGUAGE]
VCA Animal Hospital	company_name	[REDACTED_COMPANY_NAME]
Colorado Veterinary Clinic	organization_name	[REDACTED_ORGANIZATION_NAME]
Christian Democrat	political_view	[REDACTED_POLITICAL_VIEW]
Maya	first_name	[REDACTED_FIRST_NAME]
Aria and Leo	first_name	[REDACTED_FIRST_NAME]
Rockies	place_name	[REDACTED_PLACE_NAME]

Custom template¶

• format_template="***" replaces every entity with the same constant.

In [10]:

custom_config = AnonymizerConfig(replace=Redact(format_template="***"))

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

custom_preview.display_record(0)

custom_config = AnonymizerConfig(replace=Redact(format_template="***")) custom_preview = anonymizer.preview( config=custom_config, data=input_data, num_records=3, ) custom_preview.display_record(0)

[13:18:54] [INFO] 👀 Preview mode: 📂 Loaded 3 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:18:54] [INFO] 🔍 Running entity detection on 3 records

[13:18:54] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:19:21] [INFO]   |-- 📋 Detection complete — 75 entities found across 3 records (0 failed) [26.5s]

[13:19:21] [INFO]   |-- labels: first_name=22, state=6, age=5, occupation=5, city=5, organization_name=4, company_name=4, last_name=3, race_ethnicity=3, language=3, political_view=3, degree=2, field_of_study=2, education_level=2, street_address=2, place_name=1, date_of_birth=1, employment_status=1, religious_belief=1

[13:19:21] [INFO] 🔄 Running Redact replacement

[13:19:21] [INFO]   |-- 📋 Replacement complete (0 failed) [0.0s]

[13:19:21] [INFO] 🎉 Pipeline complete — 3 records processed, 0 total failures

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| organization_name, 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| company_name and later at the Colorado Veterinary Clinic| company_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

***| first_name ***| last_name, a ***| age‑year‑old ***| race_ethnicity ***| occupation living in ***| city, ***| state, grew up on the outskirts of the city and developed a love for animals early on. After graduating from ***| organization_name, he earned his ***| degree at the ***| organization_name, where he also completed a research stint in ***| field_of_study. Fluent in ***| language, ***| 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, ***| first_name has worked at ***| company_name and later at the ***| company_name, where he now leads a busy mixed‑practice team. He identifies as a ***| political_view and often volunteers at local shelters, a habit encouraged by his wife, ***| first_name, and their two teenage children, ***| first_name. Outside the clinic, ***| first_name enjoys hiking the ***| place_name with his family and mentoring veterinary students from his alma mater.

Replacement Map

Original	Label	Replacement
Bobby	first_name	***
Watford	last_name	***
40	age	***
Mexican	race_ethnicity	***
veterinarian	occupation	***
Denver	city	***
Colorado	state	***
Jefferson High	organization_name	***
DVM	degree	***
University of Colorado Boulder	organization_name	***
wildlife health	field_of_study	***
English	language	***
VCA Animal Hospital	company_name	***
Colorado Veterinary Clinic	company_name	***
Christian Democrat	political_view	***
Maya	first_name	***
Aria and Leo	first_name	***
Rockies	place_name	***

🏷️ Annotate¶

• Tags each entity with its label but keeps the original text visible. Default: <Alice, first_name>.
• Customize with format_template -- must include {text} and {label}, e.g. Annotate(format_template="<{text}-|-{label}>").

In [11]:

annotate_config = AnonymizerConfig(replace=Annotate())

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

annotate_preview.display_record(0)

annotate_config = AnonymizerConfig(replace=Annotate()) annotate_preview = anonymizer.preview( config=annotate_config, data=input_data, num_records=3, ) annotate_preview.display_record(0)

[13:19:21] [INFO] 👀 Preview mode: 📂 Loaded 3 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:19:21] [INFO] 🔍 Running entity detection on 3 records

[13:19:21] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:19:49] [INFO]   |-- 📋 Detection complete — 77 entities found across 3 records (0 failed) [27.8s]

[13:19:49] [INFO]   |-- labels: first_name=22, state=6, age=5, occupation=5, city=5, organization_name=5, company_name=4, last_name=3, race_ethnicity=3, language=3, political_view=3, degree=2, field_of_study=2, education_level=2, street_address=2, university=1, place_name=1, date_of_birth=1, employment_status=1, religious_belief=1

[13:19:49] [INFO] 🔄 Running Annotate replacement

[13:19:49] [INFO]   |-- 📋 Replacement complete (0 failed) [0.0s]

[13:19:49] [INFO] 🎉 Pipeline complete — 3 records processed, 0 total failures

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| company_name and later at the Colorado Veterinary Clinic| company_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| organization_name.

Replaced

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

Replacement Map

Original	Label	Replacement
Bobby	first_name	<Bobby, first_name>
Watford	last_name	<Watford, last_name>
40	age	<40, age>
Mexican	race_ethnicity	<Mexican, race_ethnicity>
veterinarian	occupation	<veterinarian, occupation>
Denver	city	<Denver, city>
Colorado	state	<Colorado, state>
Jefferson High	organization_name	<Jefferson High, organization_name>
DVM	degree	<DVM, degree>
University of Colorado Boulder	university	<University of Colorado Boulder, university>
wildlife health	field_of_study	<wildlife health, field_of_study>
English	language	<English, language>
VCA Animal Hospital	company_name	<VCA Animal Hospital, company_name>
Colorado Veterinary Clinic	company_name	<Colorado Veterinary Clinic, company_name>
Christian Democrat	political_view	<Christian Democrat, political_view>
Maya	first_name	<Maya, first_name>
Aria and Leo	first_name	<Aria and Leo, first_name>
Rockies	place_name	<Rockies, place_name>
alma mater	organization_name	<alma mater, organization_name>

Custom template¶

• Override the default format with any string containing {text} and {label}.

In [12]:

annotate_custom_config = AnonymizerConfig(replace=Annotate(format_template="<{text}-|-{label}>"))
annotate_custom_preview = anonymizer.preview(
    config=annotate_custom_config,
    data=input_data,
    num_records=3,
)
annotate_custom_preview.display_record(0)

annotate_custom_config = AnonymizerConfig(replace=Annotate(format_template="<{text}-|-{label}>")) annotate_custom_preview = anonymizer.preview( config=annotate_custom_config, data=input_data, num_records=3, ) annotate_custom_preview.display_record(0)

[13:19:49] [INFO] 👀 Preview mode: 📂 Loaded 3 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:19:49] [INFO] 🔍 Running entity detection on 3 records

[13:19:49] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:20:16] [INFO]   |-- 📋 Detection complete — 77 entities found across 3 records (0 failed) [26.8s]

[13:20:16] [INFO]   |-- labels: first_name=22, state=6, organization_name=6, age=5, occupation=5, city=5, last_name=3, race_ethnicity=3, language=3, company_name=3, political_view=3, education_level=3, religious_belief=2, street_address=2, degree=1, university=1, place_name=1, date_of_birth=1, field_of_study=1, employment_status=1

[13:20:16] [INFO] 🔄 Running Annotate replacement

[13:20:16] [INFO]   |-- 📋 Replacement complete (0 failed) [0.0s]

[13:20:16] [INFO] 🎉 Pipeline complete — 3 records processed, 0 total failures

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. 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| company_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

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

Replacement Map

Original	Label	Replacement
Bobby	first_name	<Bobby-|-first_name>
Watford	last_name	<Watford-|-last_name>
40	age	<40-|-age>
Mexican	race_ethnicity	<Mexican-|-race_ethnicity>
veterinarian	occupation	<veterinarian-|-occupation>
Denver	city	<Denver-|-city>
Colorado	state	<Colorado-|-state>
Jefferson High	organization_name	<Jefferson High-|-organization_name>
DVM	degree	<DVM-|-degree>
University of Colorado Boulder	university	<University of Colorado Boulder-|-university>
English	language	<English-|-language>
VCA Animal Hospital	company_name	<VCA Animal Hospital-|-company_name>
Colorado Veterinary Clinic	organization_name	<Colorado Veterinary Clinic-|-organization_name>
Christian Democrat	political_view	<Christian Democrat-|-political_view>
Maya	first_name	<Maya-|-first_name>
Aria and Leo	first_name	<Aria and Leo-|-first_name>
Rockies	place_name	<Rockies-|-place_name>

#️⃣ Hash¶

• Deterministic -- same input always produces the same hash.
• Customize with format_template (must include {digest}), algorithm (sha256/sha1/md5), and digest_length (6-64 characters).

In [13]:

hash_config = AnonymizerConfig(replace=Hash())

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

hash_preview.display_record(0)

hash_config = AnonymizerConfig(replace=Hash()) hash_preview = anonymizer.preview( config=hash_config, data=input_data, num_records=3, ) hash_preview.display_record(0)

[13:20:31] [INFO] 👀 Preview mode: 📂 Loaded 3 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:20:31] [INFO] 🔍 Running entity detection on 3 records

[13:20:31] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:21:42] [INFO]   |-- 📋 Detection complete — 78 entities found across 3 records (0 failed) [71.4s]

[13:21:42] [INFO]   |-- labels: first_name=23, state=6, age=5, occupation=5, city=5, organization_name=4, last_name=3, race_ethnicity=3, language=3, company_name=3, political_view=3, education_level=3, religious_belief=2, street_address=2, school_name=1, degree=1, university=1, clinic_name=1, place_name=1, date_of_birth=1, field_of_study=1, employment_status=1

[13:21:42] [INFO] 🔄 Running Hash replacement

[13:21:42] [INFO]   |-- 📋 Replacement complete (0 failed) [0.0s]

[13:21:42] [INFO] 🎉 Pipeline complete — 3 records processed, 0 total failures

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| school_name, he earned his DVM| degree at the University of Colorado Boulder| university, where he also completed a research stint in wildlife health. 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| company_name and later at the Colorado Veterinary Clinic| clinic_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| first_name 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

<HASH_FIRST_NAME_4a70dab2cb4d>| first_name <HASH_LAST_NAME_e2efa8a62600>| last_name, a <HASH_AGE_d59eced1ded0>| age‑year‑old <HASH_RACE_ETHNICITY_d108dfd1df5c>| race_ethnicity <HASH_OCCUPATION_52a469e4d8e9>| occupation living in <HASH_CITY_fcdeb8c07d4a>| city, <HASH_STATE_4ae62bf4e804>| state, grew up on the outskirts of the city and developed a love for animals early on. After graduating from <HASH_SCHOOL_NAME_39dde416149c>| school_name, he earned his <HASH_DEGREE_d44ae5e206d1>| degree at the <HASH_UNIVERSITY_bca201129c41>| university, where he also completed a research stint in wildlife health. Fluent in <HASH_LANGUAGE_ba118bf7fc9c>| language, <HASH_FIRST_NAME_4a70dab2cb4d>| 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, <HASH_FIRST_NAME_4a70dab2cb4d>| first_name has worked at <HASH_COMPANY_NAME_56e3eb3da5fa>| company_name and later at the <HASH_CLINIC_NAME_b45afd893ae9>| clinic_name, where he now leads a busy mixed‑practice team. He identifies as a <HASH_POLITICAL_VIEW_1eba4d0314c9>| political_view and often volunteers at local shelters, a habit encouraged by his wife, <HASH_FIRST_NAME_031e45c699d1>| first_name, and their two teenage children, <HASH_FIRST_NAME_736001faca59>| first_name and <HASH_FIRST_NAME_5bc426e8d81e>| first_name. Outside the clinic, <HASH_FIRST_NAME_4a70dab2cb4d>| first_name enjoys hiking the <HASH_PLACE_NAME_d706f1c04961>| place_name with his family and mentoring veterinary students from his alma mater.

Replacement Map

Original	Label	Replacement
Bobby	first_name	<HASH_FIRST_NAME_4a70dab2cb4d>
Watford	last_name	<HASH_LAST_NAME_e2efa8a62600>
40	age	<HASH_AGE_d59eced1ded0>
Mexican	race_ethnicity	<HASH_RACE_ETHNICITY_d108dfd1df5c>
veterinarian	occupation	<HASH_OCCUPATION_52a469e4d8e9>
Denver	city	<HASH_CITY_fcdeb8c07d4a>
Colorado	state	<HASH_STATE_4ae62bf4e804>
Jefferson High	school_name	<HASH_SCHOOL_NAME_39dde416149c>
DVM	degree	<HASH_DEGREE_d44ae5e206d1>
University of Colorado Boulder	university	<HASH_UNIVERSITY_bca201129c41>
English	language	<HASH_LANGUAGE_ba118bf7fc9c>
VCA Animal Hospital	company_name	<HASH_COMPANY_NAME_56e3eb3da5fa>
Colorado Veterinary Clinic	clinic_name	<HASH_CLINIC_NAME_b45afd893ae9>
Christian Democrat	political_view	<HASH_POLITICAL_VIEW_1eba4d0314c9>
Maya	first_name	<HASH_FIRST_NAME_031e45c699d1>
Aria	first_name	<HASH_FIRST_NAME_736001faca59>
Leo	first_name	<HASH_FIRST_NAME_5bc426e8d81e>
Rockies	place_name	<HASH_PLACE_NAME_d706f1c04961>

Custom template¶

• Override the algorithm, digest length, and output format.

In [14]:

hash_custom_config = AnonymizerConfig(replace=Hash(algorithm="md5", digest_length=8, format_template="[{digest}]"))
hash_custom_preview = anonymizer.preview(
    config=hash_custom_config,
    data=input_data,
    num_records=3,
)
hash_custom_preview.display_record(0)

hash_custom_config = AnonymizerConfig(replace=Hash(algorithm="md5", digest_length=8, format_template="[{digest}]")) hash_custom_preview = anonymizer.preview( config=hash_custom_config, data=input_data, num_records=3, ) hash_custom_preview.display_record(0)

[13:21:43] [INFO] 👀 Preview mode: 📂 Loaded 3 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:21:43] [INFO] 🔍 Running entity detection on 3 records

[13:21:43] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:22:18] [INFO]   |-- 📋 Detection complete — 76 entities found across 3 records (0 failed) [34.9s]

[13:22:18] [INFO]   |-- labels: first_name=22, state=6, age=5, occupation=5, city=5, organization_name=4, company_name=4, last_name=3, race_ethnicity=3, language=3, political_view=3, degree=2, field_of_study=2, education_level=2, street_address=2, university=1, place_name=1, date_of_birth=1, employment_status=1, religious_belief=1

[13:22:18] [INFO] 🔄 Running Hash replacement

[13:22:18] [INFO]   |-- 📋 Replacement complete (0 failed) [0.0s]

[13:22:18] [INFO] 🎉 Pipeline complete — 3 records processed, 0 total failures

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| company_name and later at the Colorado Veterinary Clinic| company_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

[657b3da9]| first_name [6e424e2c]| last_name, a [d645920e]| age‑year‑old [a0e769d8]| race_ethnicity [84c99b4a]| occupation living in [67100af8]| city, [15e49475]| state, grew up on the outskirts of the city and developed a love for animals early on. After graduating from [27c56955]| organization_name, he earned his [47211f54]| degree at the [e2b97348]| university, where he also completed a research stint in [7b2947bb]| field_of_study. Fluent in [78463a38]| language, [657b3da9]| 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, [657b3da9]| first_name has worked at [3541ebe8]| company_name and later at the [cd3abcd1]| company_name, where he now leads a busy mixed‑practice team. He identifies as a [408d2599]| political_view and often volunteers at local shelters, a habit encouraged by his wife, [719fe280]| first_name, and their two teenage children, [0efaeae5]| first_name. Outside the clinic, [657b3da9]| first_name enjoys hiking the [661f0bd9]| place_name with his family and mentoring veterinary students from his alma mater.

Replacement Map

Original	Label	Replacement
Bobby	first_name	[657b3da9]
Watford	last_name	[6e424e2c]
40	age	[d645920e]
Mexican	race_ethnicity	[a0e769d8]
veterinarian	occupation	[84c99b4a]
Denver	city	[67100af8]
Colorado	state	[15e49475]
Jefferson High	organization_name	[27c56955]
DVM	degree	[47211f54]
University of Colorado Boulder	university	[e2b97348]
wildlife health	field_of_study	[7b2947bb]
English	language	[78463a38]
VCA Animal Hospital	company_name	[3541ebe8]
Colorado Veterinary Clinic	company_name	[cd3abcd1]
Christian Democrat	political_view	[408d2599]
Maya	first_name	[719fe280]
Aria and Leo	first_name	[0efaeae5]
Rockies	place_name	[661f0bd9]

⏭️ Next steps¶

• 🕵️ Inspecting Detected Entities -- dig into what the detection pipeline found and debug quality.
• ✏️ Rewriting Biographies -- generate privacy-safe paraphrases instead of token-level replacements.
• ⚖️ Rewriting Legal Documents -- rewrite legal text with domain-specific privacy goals.