Package: ens-normalize
ENS Normalize PythonPython implementation ofENSIP-15 - the ENS Name Normalization Standard.Thanks toraffy.ethfor his leadership in coordinating the definition of this standard with the ENS community.This library is being maintained by the team atNameHash Labsas part of the greaterNameGuardsolution to help protect the ENS community.Passes100%of theofficial validation tests(validated automatically with pytest on Linux, MacOS, and Windows, see below for details).Passes anadditional suite of further testsfor compatibility with the officialJavascript reference implementationand code testing coverage.Based onJavaScript implementation version 1.9.0.GlossaryFoundationssequence- a Unicode string containing any number of characters.label separator- a full stop character (also known as a period), e.g...label- a sequence of any length (including 0) that does not contain a label separator, e.g.abcoreth.name- a series of any number of labels (including 0) separated by label separators, e.g.abc.eth.Namesnormalized name- a name that is in normalized form according to the ENS Normalization Standard. This meansname == ens_normalize(name). A normalized name contains 0 or more labels. All labels in a normalized name always contain a sequence of at least 1 valid character. An empty string contains 0 labels and is a normalized name.normalizable name- a name that is normalized or that can be converted into a normalized name usingens_normalize.beautiful name- a name that is normalizable and is equal to itself when usingens_beautify. This meansname == ens_beautify(name). For all normalizable namesens_normalize(ens_beautify(name)) == ens_normalize(name).disallowed name- a name that is not normalizable. This meansens_normalize(name)raises aDisallowedSequence.curable name- a name that is normalizable, or a name in the subset of disallowed names that can still be converted into a normalized name usingens_cure.empty name- a name that is the empty string. An empty string is a name with 0 labels. It is anormalized name.namehash ready name- a name that is ready for for use with the ENSnamehashfunction. Only normalized names are namehash ready. Empty names represent the ENS namespace root for use with the ENSnamehashfunction. Using the ENSnamehashfunction on any name that is not namehash ready will return a node that is unreachable by ENS client applications that use a proper implementation ofens_normalize.Sequencesunnormalized sequence- a sequence from a name that is not in normalized form according to the ENS Normalization Standard.normalization suggestion- a sequence suggested as an in-place replacement for an unnormalized sequence.normalizable sequence- an unnormalized sequence containing a normalization suggestion that is automatically applied usingens_normalizeandens_cure.curable sequence- an unnormalized sequence containing a normalization suggestion that is automatically applied usingens_cure.disallowed sequence- an unnormalized sequence without any normalization suggestion.The following Venn diagram is not to scale, but may help to communicate how some of the classifications of names relate to each other conceptually.UsageThe package is available onpypipipinstallens-normalizeYou can also try it in Google Colabens_normalizeNormalize an ENS name:fromens_normalizeimportens_normalize# str -> str# raises DisallowedSequence for disallowed names# output is namehash readyens_normalize('Nick.ETH')# 'nick.eth'# note: ens_normalize does not enforce any constraints that might be applied by a particular registrar. For example, the registrar for names that are a subname of '.eth' enforces a 3-character minimum and this constraint is not enforced by ens_normalize.Check if a name isnormalizable(see Glossary):fromens_normalizeimportis_ens_normalizable# str -> boolis_ens_normalizable('Nick.ETH')# TrueInspect issues with disallowed names:fromens_normalizeimportDisallowedSequence,CurableSequencetry:# added a hidden "zero width joiner" characterens_normalize('Ni‍ck.ETH')# Catch the first disallowed sequence (the name we are attempting to normalize could have more than one).exceptDisallowedSequencease:# error codeprint(e.code)# INVISIBLE# a message about why the sequence is disallowedprint(e.general_info)# Contains a disallowed invisible characterifisinstance(e,CurableSequence):# information about the curable sequenceprint(e.sequence_info)# 'This invisible character is disallowed'# starting index of the disallowed sequence in the input string# (counting in Unicode code points)print(e.index)# 2# the disallowed sequence# (use repr() to "see" the invisible character)print(repr(e.sequence))# '\u200d'# a normalization suggestion for fixing the disallowed sequence (there might be more disallowed sequences)print(repr(e.suggested))# ''# replacing the disallowed sequence with this suggestion (an empty string) represents the idea that the disallowed sequence is suggested to be removed# You may be able to fix this disallowed sequence by replacing e.sequence with e.suggested in the input string.# Fields index, sequence_info, sequence, and suggested are available only for curable errors.# Other disallowed sequences might be found even after applying this suggestion.ens_cureYou can attempt conversion of disallowed names into normalized names usingens_cure. This algorithm can “cure” many normalization errors that would failens_normalize. This can be useful in some situations. For example, if a user input failsens_normalize, a user could be prompted with a more helpful error message such as: “Did you mean curedname.eth?”.Some names are not curable. For example, if it is challenging to provide a specific normalization suggestion that might be needed to replace a disallowed sequence.Note: This function isNOTa part of the ENS Normalization Standard.fromens_normalizeimportens_cure# input name with disallowed zero width joiner and '?'# str -> strens_cure('Ni‍ck?.ETH')# 'nick.eth'# ZWJ and '?' are removed, no error is raised# note: might remove all characters from the input, which would result in an empty nameens_cure('?')# '' (empty string)# reason: '?' is disallowed and no replacement can be suggested# note: might still raise DisallowedSequence for certain names, which cannot be cured, e.g.ens_cure('0х0.eth')# DisallowedSequence: Contains visually confusing characters from Cyrillic and Latin scripts# reason: The "х" is actually a Cyrillic character that is visually confusing with the Latin "x".#         However, the "0"s are standard Latin digits and it is not clear which characters should be removed.#         They conflict with each other because it is not known if the user intended to use Cyrillic or Latin.ens_beautifyGet a beautiful name that is optimized for display:fromens_normalizeimportens_beautify# works like ens_normalize()# output ready for displayens_beautify('1⃣2⃣.eth')# '1️⃣2️⃣.eth'# note: normalization is unchanged:# ens_normalize(ens_beautify(x)) == ens_normalize(x)# note: in addition to beautifying emojis with fully-qualified emoji, ens_beautify converts the character 'ξ' (Greek lowercase 'Xi') to 'Ξ' (Greek uppercase 'Xi', a.k.a. the Ethereum symbol) in labels that contain no other Greek charactersens_tokenizeGenerate detailed name analysis:fromens_normalizeimportens_tokenize# str -> List[Token]# always returns a tokenization of the inputens_tokenize('Nàme‍🧙‍♂.eth')# [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'),#  TokenStop(cp=46, type='stop'),#  TokenValid(cps=[101, 116, 104], type='valid')]ens_normalizationsFor a normalizable name, you can find out how the input is transformed during normalization:fromens_normalizeimportens_normalizations# Returns a list of transformations (unnormalized sequence -> normalization suggestion)# that have been applied to the input during normalization.# NormalizableSequence has the same fields as CurableSequence:# - code# - general_info# - sequence_info# - index# - sequence# - suggestedens_normalizations('Nàme🧙‍♂️.eth')# [NormalizableSequence(code="MAPPED", index=0, sequence="N", suggested="n"),#  NormalizableSequence(code="FE0F", index=4, sequence="🧙‍♂️", suggested="🧙‍♂")]Example WorkflowAn example normalization workflow:name='Nàme🧙‍♂️.eth'try:normalized=ens_normalize(name)print('Normalized:',normalized)# Normalized: nàme🧙‍♂.eth# Success!# was the input transformed by the normalization process?ifname!=normalized:# Let's check how the input was changed:fortinens_normalizations(name):print(repr(t))# use repr() to print more information# NormalizableSequence(code="MAPPED", index=0, sequence="N", suggested="n")# NormalizableSequence(code="FE0F", index=4, sequence="🧙‍♂️", suggested="🧙‍♂")#                                     invisible character inside emoji ^exceptDisallowedSequencease:# Even if the name is invalid according to the ENS Normalization Standard,# we can try to automatically cure disallowed sequences.try:print('Cured:',ens_cure(name))exceptDisallowedSequencease:# The name cannot be automatically cured.print('Disallowed name error:',e)You can run many of the above functions at once. It is faster than running all of them sequentially.fromens_normalizeimportens_process# use only the do_* flags you needens_process("Nàme🧙‍♂️1⃣.eth",do_normalize=True,do_beautify=True,do_tokenize=True,do_normalizations=True,do_cure=True,)# ENSProcessResult(#   normalized='nàme🧙\u200d♂1⃣.eth',#   beautified='nàme🧙\u200d♂️1️⃣.eth',#   tokens=[...],#   cured='nàme🧙\u200d♂1⃣.eth',#   cures=[], # This is the list of cures that were applied to the input (in this case, none).#   error=None, # This is the exception raised by ens_normalize().#               # It is a DisallowedSequence or CurableSequence if the error is curable.#   normalizations=[#     NormalizableSequence(code="MAPPED", index=0, sequence="N", suggested="n"),#     NormalizableSequence(code="FE0F", index=4, sequence="🧙‍♂️", suggested="🧙‍♂")#   ])ExceptionsThese Python classes are used by the library to communicate information about unnormalized sequences.Exception classens_normalizehandlingens_curehandlingnormalizationsuggestionInherits FromNormalizableSequence✅ automatically resolves✅ automatically resolves✅ includedCurableSequenceCurableSequence❌ throws error✅ automatically resolves✅ includedDisallowedSequenceDisallowedSequence❌ throws error❌ throws error❌ noneExceptionList of allNormalizableSequencetypesNormalizableSequenceTypeGeneral infoSequence infoIGNOREDContains a disallowed "ignored" character that has been removedThis character is ignored during normalization and has been automatically removedMAPPEDContains a disallowed character that has been replaced by a normalized sequenceThis character is disallowed and has been automatically replaced by a normalized sequenceFE0FContains a disallowed variant of an emoji which has been replaced by an equivalent normalized emojiThis emoji has been automatically fixed to remove an invisible characterNFCContains a disallowed sequence that is not "NFC normalized" which has been replaced by an equivalent normalized sequenceThis sequence has been automatically normalized into NFC canonical formList of allCurableSequencetypesCurable errors contain additional information about the disallowed sequence and a normalization suggestion that might help to cure the name.CurableSequenceTypeGeneral infoSequence infoUNDERSCOREContains an underscore in a disallowed positionAn underscore is only allowed at the start of a labelHYPHENContains the sequence '--' in a disallowed positionHyphens are disallowed at the 2nd and 3rd positions of a labelEMPTY_LABELContains a disallowed empty labelEmpty labels are not allowed, e.g. abc..ethCM_STARTContains a combining mark in a disallowed position at the start of the labelA combining mark is disallowed at the start of a labelCM_EMOJIContains a combining mark in a disallowed position after an emojiA combining mark is disallowed after an emojiDISALLOWEDContains a disallowed characterThis character is disallowedINVISIBLEContains a disallowed invisible characterThis invisible character is disallowedFENCED_LEADINGContains a disallowed character at the start of a labelThis character is disallowed at the start of a labelFENCED_MULTIContains a disallowed consecutive sequence of charactersCharacters in this sequence cannot be placed next to each otherFENCED_TRAILINGContains a disallowed character at the end of a labelThis character is disallowed at the end of a labelCONF_MIXEDContains visually confusing characters from multiple scripts ({script1}/{script2})This character from the {script1} script is disallowed because it is visually confusing with another character from the {script2} scriptList of allDisallowedSequencetypesDisallowed name errors are not considered curable because it may be challenging to suggest a specific normalization suggestion that might resolve the problem.DisallowedSequenceTypeGeneral infoExplanationNSM_REPEATEDContains a repeated non-spacing markNon-spacing marks can be encoded as one codepoint with the preceding character, which makes it difficult to suggest a normalization suggestionNSM_TOO_MANYContains too many consecutive non-spacing marksNon-spacing marks can be encoded as one codepoint with the preceding character, which makes it difficult to suggest a normalization suggestionCONF_WHOLEContains visually confusing characters from {script1} and {script2} scriptsBoth characters are equally likely to be the correct character to use and a normalization suggestion cannot be providedDevelopmentUpdate this library to the latest ENS normalization specification(optional)This library uses files defining the normalization standard
directly from theofficial Javascript implementation.
When the standard is updated with new characters, this library can
be updated by running the following steps:Requirements:Node.js>= 18npmSet the hash of the latest commit from theJavaScript libraryinsidepackage.jsonRun the updater:cdtools/updater
npmstartBuild and testInstalls dependencies, runs validation tests and builds the wheel.Install requirements:PythonPoetryInstall dependencies:poetryinstallRun tests (including official validation tests):poetryrunpytestBuild Python wheel:poetrybuild