Masking¶

The utkit.privacy.mask module provides utilities for masking sensitive data such as email addresses, phone numbers, payment card numbers, and arbitrary strings before displaying or logging them.

No external dependencies are required — the module uses Python's built-in re library.

Quick start¶

from utkit.privacy.mask import mask_email, mask_phone, mask_card, mask_string

mask_email("john.doe@example.com")   # "jo******@example.com"
mask_phone("+1 (555) 123-4567")      # "*******4567"
mask_card("4111 1111 1111 1111")     # "4111********1111"
mask_string("Hello, World!")         # "He*********d!"

mask_email¶

Masks the local part of an email address, keeping the first two characters visible.

def mask_email(email: str) -> str

Returns: str — the masked email address. Returns the original value unchanged if it is empty or does not contain @.

mask_email("john.doe@example.com")  # "jo******@example.com"

mask_phone¶

Masks a phone number, keeping only the last 4 digits visible. Non-digit characters are stripped before masking.

def mask_phone(phone: str) -> str

Returns: str — the masked phone number. Returns the original value unchanged if it is empty.

mask_phone("+1 (555) 123-4567")  # "*******4567"

mask_card¶

Masks a payment card number, keeping the first 4 and last 4 digits visible. Non-digit characters are stripped before masking.

def mask_card(card: str) -> str

Returns: str — the masked card number. Returns the original value unchanged if it is empty.

mask_card("4111 1111 1111 1111")  # "4111********1111"

mask_string¶

Masks an arbitrary string, keeping a configurable number of characters visible at the start and end.

def mask_string(value: str, visible_start: int = 2, visible_end: int = 2) -> str

Returns: str — the masked string. If the value is shorter than or equal to visible_start + visible_end, the entire string is masked with *. Returns the original value unchanged if it is empty.

mask_string("Hello, World!")            # "He*********d!"
mask_string("API-KEY-12345", 3, 3)      # "API*******345"