ens-normalize 1.8.9.post1

Ethereum Name Service (ENS) Name Normalizer

ens-normalize

• Python implementation of the ENS Name Normalization Standard
• Passes 100% of official validation tests (validated automatically with pytest, see below)
• Passes additional tests for compatibility with the official library
• Based on JavaScript implementation version 1.8.9

Usage

The package is available on pypi

pip install ens-normalize

Use the main functions:

from ens_normalize import ens_normalize, ens_beautify

# str -> str
# raises ValueError for invalid names
# output ready for namehash
ens_normalize('Nick.ETH')
# 'nick.eth'
# added a hidden "zero width joiner" character
ens_normalize('Ni‍ck.ETH')
# ValueError: Contains a disallowed invisible character

# works like ens_normalize()
# output ready for display
ens_beautify('1⃣2⃣.eth')
# '1️⃣2️⃣.eth'

Detailed label analysis:

from ens_normalize import ens_tokenize
# str -> List[Token]
# always returns a tokenization of the input
ens_tokenize('Nàme‍🧙‍♂')
# [TokenMapped(cp=78, cps=[110], type='mapped'),
#  TokenNFC(input=[97, 768], cps=[224], type='nfc'),
#  TokenValid(cps=[109, 101], type='valid'),
#  TokenDisallowed(cp=8205, type='disallowed'),
#  TokenEmoji(emoji=[129497, 8205, 9794, 65039],
#             input=[129497, 8205, 9794],
#             cps=[129497, 8205, 9794],
#             type='emoji')]

Advanced usage:

from ens_normalize import ens_process
# compute many functions in one call
# do_* arguments control what is computed
ens_process('Nick.ETH',
    # ens_normalize()
    do_normalize=True,
    # ens_beautify()
    do_beautify=True,
    # ens_tokenize()
    do_tokenize=True,
    # the reason why the input is not normalized
    do_reason=True)
# ENSProcessResult(
#     normalized='nick.eth',
#     beautified='nick.eth',
#     tokens=[...],
#     # error is None if name is normalized
#     error=NormalizationError(
#         type=NormalizationErrorType.NORM_ERR_MAPPED,
#         # position of the error
#         start=0,
#         # the substring that is disallowed
#         disallowed='N',
#         # how to fix the error
#         suggested='n'),
#     # is the above error fatal (input disallowed)
#     # or is it a warning (input can be normalized)
#     is_fatal=False)

Using error information:

from ens_normalize import is_ens_normalized
name = 'Nick.eth'
# do_reason=True to output error information
res = ens_process(name, do_reason=True)
print(res.error.message)
# Contains a disallowed "mapped" sequence that is disallowed from inclusion in a label when it is saved to the blockchain during a valid registration
print(res.error.disallowed, '=>', res.error.suggested)
# N => n
# fix the error
name = name.replace(
    res.error.disallowed,
    res.error.suggested,
)
is_ens_normalized(name)
# True

Get more information about the error:

from ens_normalize import NormalizationErrorType
NormalizationErrorType.NORM_ERR_NFC.message
# 'Contains a disallowed sequence that is not "NFC normalized" into canonical form'
NormalizationErrorType.NORM_ERR_NFC.details
# 'This sequence should be correctly "NFC normalized" into its canonical form when it is saved to the blockchain during a valid registration'

List of reported errors

Error type	Description	Error fix suggestion
NORM_ERR_UNDERSCORE	Contains an underscore in a disallowed position	✅
NORM_ERR_HYPHEN	Contains the sequence '--' in a disallowed position	✅
NORM_ERR_EMPTY	Contains a disallowed empty label	✅
NORM_ERR_OTHER	Internal error during normalization	❌
NORM_ERR_CM_START	Contains a combining mark in a disallowed position at the start of the label	✅
NORM_ERR_CM_EMOJI	Contains a combining mark in a disallowed position after an emoji	✅
NORM_ERR_CM_MULTI	Contains a disallowed sequence of multiple sequential combining marks	✅
NORM_ERR_DISALLOWED	Contains a disallowed character	✅
NORM_ERR_INVISIBLE	Contains a disallowed invisible character	✅
NORM_ERR_IGNORED	Contains a disallowed character that is ignored during normalization	✅
NORM_ERR_MAPPED	Contains a disallowed character that is changed (mapped) to another sequence during normalization	✅
NORM_ERR_FE0F	Contains a disallowed invisible character inside an emoji	✅
NORM_ERR_NFC	Contains a disallowed sequence that is not "NFC normalized" into canonical form	✅
NORM_ERR_FENCED_LEADING	Contains a disallowed character at the start of a label	✅
NORM_ERR_FENCED_MULTI	Contains a disallowed sequence of 2 characters	✅
NORM_ERR_FENCED_TRAILING	Contains a disallowed character at the end of a label	✅
NORM_ERR_CONF_WHOLE	Contains whole-script confusables	❌
NORM_ERR_CONF_MIXED	Contains mixed-script confusables	✅

Develop

Update the ENS normalization specification (optional)

This library uses files defining the normalization standard directly from the official implementation. When the standard is updated with new characters, this library can be updated by running this step.

1. Requirements:
   • Node.js >= 18
   • npm
2. Set the hash of the latest commit from the JavaScript library inside package.json
3. Run the updater:

   cd tools/updater
   npm start
   

Build and test

Installs dependencies, runs validation tests and builds the wheel.

1. Install requirements:

   • Python
   • Poetry

2. Install dependencies:

   poetry install
   

3. Run tests (including official validation tests):

   poetry run pytest
   

4. Build Python wheel:

   poetry build