🕵️ 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.
  • Treat the default build.nvidia.com setup as a convenient experimentation path. For privacy-sensitive or production data, switch to a secure endpoint you trust and to which you are comfortable sending data.
  • Request/token rate limits on build.nvidia.com vary by account and model access, and lower-volume development access can be slow for full runs. Start with preview() on a small sample.
• Import all four strategy classes: Redact, Annotate, Hash, Substitute.
• Anonymizer() initializes with the default model provider -- no extra config needed.
• Anonymizer.configure_logging() controls verbosity -- switch to Anonymizer.configure_logging(LoggingConfig.debug()) when troubleshooting.

In [1]:

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 [2]:

from anonymizer import Annotate, Anonymizer, AnonymizerConfig, AnonymizerInput, Hash, Redact, Substitute

from anonymizer import Annotate, Anonymizer, AnonymizerConfig, AnonymizerInput, Hash, Redact, Substitute

In [3]:

anonymizer = Anonymizer()

anonymizer = Anonymizer()

[13:40:20] [INFO] 🔧 Anonymizer initialized with 3 model configs

[13:40:20] [INFO]   |-- 🔎 detector:  gliner-pii-detector

[13:40:20] [INFO]   |-- ✅ validator: gpt-oss-120b

[13:40:20] [INFO]   |-- 🧩 augmenter: gpt-oss-120b

📦 Input data¶

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

In [4]:

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 [5]:

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, )

[13:40:20] [INFO] 📂 Loaded 25 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:40:20] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:40:20] [INFO]   |-- 👀 Preview mode: processing 3 of 25 records

[13:40:20] [INFO] 🔍 Running entity detection on 3 records

[13:41:02] [INFO]   |-- 📋 Detection complete — 79 entities found across 3 records (0 failed) [41.5s]

[13:41:02] [INFO]   |-- labels: first_name=22, organization_name=8, age=5, occupation=5, city=4, state=4, degree=4, university=4, field_of_study=4, political_view=4, last_name=3, race_ethnicity=3, language=2, street_address=2, place_name=1, date_of_birth=1, device_identifier=1, employment_status=1, religious_belief=1

[13:41:02] [INFO] 🔄 Running Substitute replacement

[13:41:18] [INFO]   |-- 📋 Replacement complete (0 failed) [16.0s]

[13:41:18] [INFO] 🎉 Pipeline complete — 3 records processed, 0 total failures

In [6]:

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| 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

Diego| first_name Sanchez| last_name, a 52| age‑year‑old Filipino| race_ethnicity marine biologist| 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 Doctor of Dental Surgery| degree at the University of Oregon| university, where he also completed a research stint in environmental toxicology| field_of_study. Fluent in Spanish| language, Diego| 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, Diego| first_name has worked at Pacific Veterinary Group| organization_name and later at the Oregon Animal Care 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, Isabel| first_name, and their two teenage children, Sofia and Mateo| first_name. Outside the clinic, Diego| 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	Diego
Christian Democrat	political_view	Libertarian
Colorado	state	Oregon
Colorado Veterinary Clinic	organization_name	Oregon Animal Care Center
DVM	degree	Doctor of Dental Surgery
Denver	city	Portland
English	language	Spanish
Jefferson High	organization_name	Lincoln High
Maya	first_name	Isabel
Mexican	race_ethnicity	Filipino
Rockies	place_name	Sierra Nevada
University of Colorado Boulder	university	University of Oregon
VCA Animal Hospital	organization_name	Pacific Veterinary Group
Watford	last_name	Sanchez
veterinarian	occupation	marine biologist
wildlife health	field_of_study	environmental toxicology

Custom instructions¶

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

In [7]:

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)

[13:41:18] [INFO] 📂 Loaded 25 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:41:18] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:41:18] [INFO]   |-- 👀 Preview mode: processing 3 of 25 records

[13:41:18] [INFO] 🔍 Running entity detection on 3 records

[13:41:53] [INFO]   |-- 📋 Detection complete — 77 entities found across 3 records (0 failed) [34.7s]

[13:41:53] [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, employment_status=1

[13:41:53] [INFO] 🔄 Running Substitute replacement

[13:42:12] [INFO]   |-- 📋 Replacement complete (0 failed) [19.5s]

[13:42:12] [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| 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

Takashi| first_name Tanaka| last_name, a 45| age‑year‑old Japanese| race_ethnicity zoologist| 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 Sapporo North High School| organization_name, he earned his 理学修士| degree at the Hokkaido University| university, where he also completed a research stint in marine biology| field_of_study. Fluent in Japanese| language, Takashi| 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, Takashi| first_name has worked at Sapporo Veterinary Hospital| organization_name and later at the Sapporo Animal Clinic| organization_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, Yuki| first_name, and their two teenage children, Sakura and Haru| first_name. Outside the clinic, Takashi| first_name enjoys hiking the Japanese Alps| 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	Sakura and Haru
Bobby	first_name	Takashi
Christian Democrat	political_view	Liberal Democratic Party
Colorado	state	Hokkaido
Colorado Veterinary Clinic	organization_name	Sapporo Animal Clinic
DVM	degree	理学修士
Denver	city	Sapporo
English	language	Japanese
Jefferson High	organization_name	Sapporo North High School
Maya	first_name	Yuki
Mexican	race_ethnicity	Japanese
Rockies	place_name	Japanese Alps
University of Colorado Boulder	university	Hokkaido University
VCA Animal Hospital	organization_name	Sapporo Veterinary Hospital
Watford	last_name	Tanaka
veterinarian	occupation	zoologist
wildlife health	field_of_study	marine biology

🚫 Redact¶

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

In [8]:

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)

[13:42:12] [INFO] 📂 Loaded 25 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:42:12] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:42:12] [INFO]   |-- 👀 Preview mode: processing 3 of 25 records

[13:42:12] [INFO] 🔍 Running entity detection on 3 records

[13:43:00] [INFO]   |-- 📋 Detection complete — 78 entities found across 3 records (0 failed) [47.6s]

[13:43:00] [INFO]   |-- labels: first_name=23, 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, employment_status=1

[13:43:00] [INFO] 🔄 Running Redact replacement

[13:43:00] [INFO]   |-- 📋 Replacement complete (0 failed) [0.0s]

[13:43:00] [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| 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| 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

[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_DEGREE]| degree at the [REDACTED_UNIVERSITY]| university, where he also completed a research stint in [REDACTED_FIELD_OF_STUDY]| field_of_study. 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_ORGANIZATION_NAME]| organization_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 and [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	degree	[REDACTED_DEGREE]
University of Colorado Boulder	university	[REDACTED_UNIVERSITY]
wildlife health	field_of_study	[REDACTED_FIELD_OF_STUDY]
English	language	[REDACTED_LANGUAGE]
VCA Animal Hospital	organization_name	[REDACTED_ORGANIZATION_NAME]
Colorado Veterinary Clinic	organization_name	[REDACTED_ORGANIZATION_NAME]
Christian Democrat	political_view	[REDACTED_POLITICAL_VIEW]
Maya	first_name	[REDACTED_FIRST_NAME]
Aria	first_name	[REDACTED_FIRST_NAME]
Leo	first_name	[REDACTED_FIRST_NAME]
Rockies	place_name	[REDACTED_PLACE_NAME]

Custom template¶

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

In [9]:

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)

[13:43:00] [INFO] 📂 Loaded 25 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:43:00] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:43:00] [INFO]   |-- 👀 Preview mode: processing 3 of 25 records

[13:43:00] [INFO] 🔍 Running entity detection on 3 records

[13:43:41] [INFO]   |-- 📋 Detection complete — 77 entities found across 3 records (0 failed) [41.7s]

[13:43:41] [INFO]   |-- labels: first_name=22, organization_name=8, age=5, occupation=5, city=4, state=4, degree=4, university=4, field_of_study=4, last_name=3, race_ethnicity=3, language=2, political_view=2, religious_belief=2, street_address=2, place_name=1, date_of_birth=1, employment_status=1

[13:43:41] [INFO] 🔄 Running Redact replacement

[13:43:41] [INFO]   |-- 📋 Replacement complete (0 failed) [0.0s]

[13:43:41] [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| 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

***| 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 ***| university, 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 ***| organization_name and later at the ***| organization_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	university	***
wildlife health	field_of_study	***
English	language	***
VCA Animal Hospital	organization_name	***
Colorado Veterinary Clinic	organization_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 [10]:

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)

[13:43:41] [INFO] 📂 Loaded 25 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:43:41] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:43:41] [INFO]   |-- 👀 Preview mode: processing 3 of 25 records

[13:43:41] [INFO] 🔍 Running entity detection on 3 records

[13:44:26] [INFO]   |-- 📋 Detection complete — 79 entities found across 3 records (0 failed) [44.4s]

[13:44:26] [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, company_name=1

[13:44:26] [INFO] 🔄 Running Annotate replacement

[13:44:26] [INFO]   |-- 📋 Replacement complete (0 failed) [0.0s]

[13:44:26] [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| 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

<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, organization_name>| organization_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>
wildlife health	field_of_study	<wildlife health, field_of_study>
English	language	<English, language>
VCA Animal Hospital	organization_name	<VCA Animal Hospital, organization_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>

Custom template¶

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

In [11]:

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)

[13:44:26] [INFO] 📂 Loaded 25 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:44:26] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:44:26] [INFO]   |-- 👀 Preview mode: processing 3 of 25 records

[13:44:26] [INFO] 🔍 Running entity detection on 3 records

[13:45:13] [INFO]   |-- 📋 Detection complete — 78 entities found across 3 records (0 failed) [46.6s]

[13:45:13] [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, telescope_name=1, employment_status=1

[13:45:13] [INFO] 🔄 Running Annotate replacement

[13:45:13] [INFO]   |-- 📋 Replacement complete (0 failed) [0.0s]

[13:45:13] [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| 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

<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-|-organization_name>| organization_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>
wildlife health	field_of_study	<wildlife health-|-field_of_study>
English	language	<English-|-language>
VCA Animal Hospital	organization_name	<VCA Animal Hospital-|-organization_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 [12]:

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)

[13:45:13] [INFO] 📂 Loaded 25 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:45:13] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:45:13] [INFO]   |-- 👀 Preview mode: processing 3 of 25 records

[13:45:13] [INFO] 🔍 Running entity detection on 3 records

[13:45:56] [INFO]   |-- 📋 Detection complete — 77 entities found across 3 records (0 failed) [43.3s]

[13:45:56] [INFO]   |-- labels: first_name=21, organization_name=8, age=5, occupation=5, city=4, state=4, degree=4, university=4, field_of_study=4, political_view=3, last_name=2, race_ethnicity=2, language=2, religious_belief=2, street_address=2, place_name=1, full_name=1, date_of_birth=1, nationality=1, employment_status=1

[13:45:56] [INFO] 🔄 Running Hash replacement

[13:45:56] [INFO]   |-- 📋 Replacement complete (0 failed) [0.0s]

[13:45:56] [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| 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

<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_ORGANIZATION_NAME_39dde416149c>| organization_name, he earned his <HASH_DEGREE_d44ae5e206d1>| degree at the <HASH_UNIVERSITY_bca201129c41>| university, where he also completed a research stint in <HASH_FIELD_OF_STUDY_c27b00db54db>| field_of_study. 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_ORGANIZATION_NAME_56e3eb3da5fa>| organization_name and later at the <HASH_ORGANIZATION_NAME_b45afd893ae9>| organization_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_b4c3f91ad0ce>| 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	organization_name	<HASH_ORGANIZATION_NAME_39dde416149c>
DVM	degree	<HASH_DEGREE_d44ae5e206d1>
University of Colorado Boulder	university	<HASH_UNIVERSITY_bca201129c41>
wildlife health	field_of_study	<HASH_FIELD_OF_STUDY_c27b00db54db>
English	language	<HASH_LANGUAGE_ba118bf7fc9c>
VCA Animal Hospital	organization_name	<HASH_ORGANIZATION_NAME_56e3eb3da5fa>
Colorado Veterinary Clinic	organization_name	<HASH_ORGANIZATION_NAME_b45afd893ae9>
Christian Democrat	political_view	<HASH_POLITICAL_VIEW_1eba4d0314c9>
Maya	first_name	<HASH_FIRST_NAME_031e45c699d1>
Aria and Leo	first_name	<HASH_FIRST_NAME_b4c3f91ad0ce>
Rockies	place_name	<HASH_PLACE_NAME_d706f1c04961>

Custom template¶

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

In [13]:

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)

[13:45:56] [INFO] 📂 Loaded 25 records from https://raw.githubusercontent.com/NVIDIA-NeMo/Anonymizer/refs/heads/main/docs/data/NVIDIA_synthetic_biographies.csv (column: 'biography')

[13:45:56] [INFO] detection labels in scope: (default: 65 labels; see anonymizer.DEFAULT_ENTITY_LABELS for list)

[13:45:56] [INFO]   |-- 👀 Preview mode: processing 3 of 25 records

[13:45:56] [INFO] 🔍 Running entity detection on 3 records

[13:46:37] [INFO]   |-- 📋 Detection complete — 77 entities found across 3 records (0 failed) [41.4s]

[13:46:37] [INFO]   |-- labels: first_name=23, 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, street_address=2, place_name=1, date_of_birth=1, employment_status=1, religious_belief=1

[13:46:37] [INFO] 🔄 Running Hash replacement

[13:46:37] [INFO]   |-- 📋 Replacement complete (0 failed) [0.0s]

[13:46:37] [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| 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| 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

[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]| organization_name and later at the [cd3abcd1]| organization_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, [a1a013e2]| first_name and [550eadb8]| 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	organization_name	[3541ebe8]
Colorado Veterinary Clinic	organization_name	[cd3abcd1]
Christian Democrat	political_view	[408d2599]
Maya	first_name	[719fe280]
Aria	first_name	[a1a013e2]
Leo	first_name	[550eadb8]
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.