Package: idna
Support for the Internationalized Domain Names in
Applications (IDNA) protocol as specified inRFC 5891. This is the latest version of
the protocol and is sometimes referred to as “IDNA 2008”.This library also provides support for Unicode Technical
Standard 46,Unicode IDNA Compatibility Processing.This acts as a suitable replacement for the “encodings.idna”
module that comes with the Python standard library, but which
only supports the older superseded IDNA specification (RFC 3490).Basic functions are simply executed:>>>importidna>>>idna.encode('ドメイン.テスト')b'xn--eckwd4c7c.xn--zckzah'>>>print(idna.decode('xn--eckwd4c7c.xn--zckzah'))ドメイン.テストInstallationThis package is available for installation from PyPI:$python3-mpipinstallidnaUsageFor typical usage, theencodeanddecodefunctions will take a
domain name argument and perform a conversion to A-labels or U-labels
respectively.>>>importidna>>>idna.encode('ドメイン.テスト')b'xn--eckwd4c7c.xn--zckzah'>>>print(idna.decode('xn--eckwd4c7c.xn--zckzah'))ドメイン.テストYou may use the codec encoding and decoding methods using theidna.codecmodule:>>>importidna.codec>>>print('домен.испытание'.encode('idna2008'))b'xn--d1acufc.xn--80akhbyknj4f'>>>print(b'xn--d1acufc.xn--80akhbyknj4f'.decode('idna2008'))домен.испытаниеConversions can be applied at a per-label basis using theulabeloralabelfunctions if necessary:>>>idna.alabel('测试')b'xn--0zwm56d'Compatibility Mapping (UTS #46)As described inRFC 5895, the
IDNA specification does not normalize input from different potential
ways a user may input a domain name. This functionality, known as
a “mapping”, is considered by the specification to be a local
user-interface issue distinct from IDNA conversion functionality.This library provides one such mapping that was developed by the
Unicode Consortium. Known asUnicode IDNA Compatibility Processing, it provides for both a regular
mapping for typical applications, as well as a transitional mapping to
help migrate from older IDNA 2003 applications.For example, “Königsgäßchen” is not a permissible label asLATIN
CAPITAL LETTER Kis not allowed (nor are capital letters in general).
UTS 46 will convert this into lower case prior to applying the IDNA
conversion.>>>importidna>>>idna.encode('Königsgäßchen')...idna.core.InvalidCodepoint: Codepoint U+004B at position 1 of 'Königsgäßchen' not allowed>>>idna.encode('Königsgäßchen',uts46=True)b'xn--knigsgchen-b4a3dun'>>>print(idna.decode('xn--knigsgchen-b4a3dun'))königsgäßchenTransitional processing provides conversions to help transition from
the older 2003 standard to the current standard. For example, in the
original IDNA specification, theLATIN SMALL LETTER SHARP S(ß) was
converted into twoLATIN SMALL LETTER S(ss), whereas in the current
IDNA specification this conversion is not performed.>>>idna.encode('Königsgäßchen',uts46=True,transitional=True)'xn--knigsgsschen-lcb0w'Implementers should use transitional processing with caution, only in
rare cases where conversion from legacy labels to current labels must be
performed (i.e. IDNA implementations that pre-date 2008). For typical
applications that just need to convert labels, transitional processing
is unlikely to be beneficial and could produce unexpected incompatible
results.encodings.idnaCompatibilityFunction calls from the Python built-inencodings.idnamodule are
mapped to their IDNA 2008 equivalents using theidna.compatmodule.
Simply substitute theimportclause in your code to refer to the new
module name.ExceptionsAll errors raised during the conversion following the specification
should raise an exception derived from theidna.IDNAErrorbase
class.More specific exceptions that may be generated asidna.IDNABidiErrorwhen the error reflects an illegal combination of left-to-right and
right-to-left characters in a label;idna.InvalidCodepointwhen
a specific codepoint is an illegal character in an IDN label (i.e.
INVALID); andidna.InvalidCodepointContextwhen the codepoint is
illegal based on its positional context (i.e. it is CONTEXTO or CONTEXTJ
but the contextual requirements are not satisfied.)Building and DiagnosticsThe IDNA and UTS 46 functionality relies upon pre-calculated lookup
tables for performance. These tables are derived from computing against
eligibility criteria in the respective standards. These tables are
computed using the command-line scripttools/idna-data.This tool will fetch relevant codepoint data from the Unicode repository
and perform the required calculations to identify eligibility. There are
three main modes:idna-datamake-libdata. Generatesidnadata.pyanduts46data.py, the pre-calculated lookup tables used for IDNA and
UTS 46 conversions. Implementers who wish to track this library against
a different Unicode version may use this tool to manually generate a
different version of theidnadata.pyanduts46data.pyfiles.idna-datamake-table. Generate a table of the IDNA disposition
(e.g. PVALID, CONTEXTJ, CONTEXTO) in the format found in Appendix
B.1 of RFC 5892 and the pre-computed tables published byIANA.idna-dataU+0061. Prints debugging output on the various
properties associated with an individual Unicode codepoint (in this
case, U+0061), that are used to assess the IDNA and UTS 46 status of a
codepoint. This is helpful in debugging or analysis.The tool accepts a number of arguments, described usingidna-data-h. Most notably, the--versionargument allows the specification
of the version of Unicode to be used in computing the table data. For
example,idna-data--version9.0.0make-libdatawill generate
library data against Unicode 9.0.0.Additional NotesPackages. The latest tagged release version is published in thePython Package Index.Version support. This library supports Python 3.5 and higher.
As this library serves as a low-level toolkit for a variety of
applications, many of which strive for broad compatibility with older
Python versions, there is no rush to remove older interpreter support.
Removing support for older versions should be well justified in that the
maintenance burden has become too high.Python 2. Python 2 is supported by version 2.x of this library.
While active development of the version 2.x series has ended, notable
issues being corrected may be backported to 2.x. Use “idna<3” in your
requirements file if you need this library for a Python 2 application.Testing. The library has a test suite based on each rule of the
IDNA specification, as well as tests that are provided as part of the
Unicode Technical Standard 46,Unicode IDNA Compatibility Processing.Emoji. It is an occasional request to support emoji domains in
this library. Encoding of symbols like emoji is expressly prohibited by
the technical standard IDNA 2008 and emoji domains are broadly phased
out across the domain industry due to associated security risks. For
now, applications that need to support these non-compliant labels
may wish to consider trying the encode/decode operation in this library
first, and then falling back to usingencodings.idna. Seethe Github
projectfor more discussion.