leptris (Python) — lxml-shaped bindings for libleptris

leptris wraps the libleptris C API (XML 1.0 parsing, XPath 1.0) using cffi in ABI mode, with a required C accelerator for Element allocation and the hot accessors (tag, text, attrib, get, indexing, sibling navigation and plain-path XPath evaluation). Wheels ship it compiled; sdist builds require a C compiler.

The pinned libleptris version lives in libleptris-version.txt (lockstep releases); CI builds it from the release tarball. The binding loads the shared library from LEPTRIS_LIB_PATH or the loader path.

Requirements

  • Python 3.9+
  • cffi (installed automatically)
  • libleptris 1.9.3+ as a shared library (1.9.1 has an options-struct ABI break — leptris/leptris#568)
  • libleptris as a shared library (libleptris.dylib / .so / .dll) on the loader path, or pointed to by LEPTRIS_LIB_PATH (which must name the library file — the loader dlopens it verbatim). For a development checkout:
cmake -B build -S /path/to/leptris -DLEPTRIS_BUILD_SHARED=ON
cmake --build build --target leptris_shared
export LEPTRIS_LIB_PATH=/path/to/leptris/build/src/libleptris.dylib

Quick start

from leptris import fromstring, tostring

root = fromstring("<library><book id='1' lang='en'>Ulysses</book></library>")

root.tag                                # "library"
root[0].get("id")                       # "1"
root[0].attrib                          # {"id": "1", "lang": "en"}
root[0].text                            # "Ulysses"

root.xpath("count(//book)")             # 1.0
[b.text for b in root.findall("book")]  # ["Ulysses"]

tostring(root[0], encoding="unicode")   # "<book id=\"1\" lang=\"en\">Ulysses</book>"

Documents own the tree; use the context manager or close():

from leptris import parse

with parse("catalog.xml") as doc:
    doc.xpath("//book[@lang='en']")

Namespaces, variables, canonical XML and streaming:

root.xpath("//x:item", namespaces={"x": "urn:ex"})
root.xpath("//book[@id=$id]", variables={"id": "2"})
c14n(root, exclusive=True)

from leptris import sax
sax.parse(xml, handler)                       # one-shot
with sax.StreamingParser(handler) as parser:  # push, constant memory
    parser.feed(chunk, final=last)

XSLT and XPath version support

leptris.XSLT(stylesheet) compiles once, applies to any Document, and returns a Document; leptris.XPath(expression) compiles an XPath for repeated evaluation. Which language constructs work is decided by the engine — the matrix below is measured against libleptris 1.9.32 (audited through this binding; the upstream gap ledger is leptris/leptris#685).

language status notes
XSLT 1.0 full libxslt conformance suite 205/205 upstream; EXSLT math/set/str/date included
XSLT 2.0 partial ✓ for-each-group, analyze-string + regex-group(), xsl:number formats, xsl:assert, xsl:sequence (multi-item), xsl:perform-sort · ✗ xsl:function, tunnel parameters, shadow attributes, xsl:result-document, @separator
XSLT 3.0 increments ✓ try/catch (with $err:description), accumulator (gated by xsl:mode use-accumulators), iterate + break + on-completion, on-empty, evaluate, grouping, modes, where-populated, on-non-empty, next-match, fork, @start-at, composite keys, tunnel params, copy/@select, xsl:namespace, xsl:document, @default, merge, result-document (writes the href target), character maps · ✗ package, xsl:map, xsl:evaluate with-params, next-iteration chaining
XPath 1.0 full complete core function library
XPath 2.0 grammar complete ✓ quantified (some/every), set algebra (union/intersect/except), node comparisons (is, <<, >>), (), ends-with, deep-equal, value comparisons, cast/castable/treat/instance of, function items + HOFs (1.9.73+) · function slices by group (sequences, regex, math:, strings/QNames/URIs, dates, xs: constructors); remaining: format-date/format-time, JSON, map:/array: constructors · format-number works in plain XPath since 1.9.80
XPath 3.1 lane 0 ✓ let, simple map !, arrow =>, string concat || — through both XPath() and XSLT · ✗ function items, inline functions, maps, arrays, string constructors
XQuery 1.0 core + 3.x increments leptris.XQuery(query) — FLWOR (for/let/where/order by/return/group by, positional at, tumbling/sliding windows), prolog (declare variable/namespace/function local:*), constructors, doc()/collection(), try/catch, typeswitch — libleptris 1.9.68+; 3.1 remainder (maps/arrays, modules) tracked in #684

XQuery 1.0 core is a first-class API since libleptris 1.9.64:

from leptris import Document, XQuery

with Document.parse("<r><item v='1'>alpha</item><item v='5'>beta</item></r>") as doc:
    XQuery("for $i in //item where $i/@v > 1 return string($i)")(doc)  # ['beta']
    XQuery("declare variable $n := 3; <out>{$n * 2}</out>")(doc)       # '<out>6</out>'
    XQuery("declare function local:dbl($x) { $x * 2 }; local:dbl(4)")(doc)  # 8.0

XPath 3.1 composition and XSLT 3.0 instructions flow through the existing API with zero binding change:

from leptris import Document, XPath, XSLT, tostring

with Document.parse("<r><item v='1'>alpha</item><item v='5'>beta</item></r>") as doc:
    doc.getroot().xpath("let $n := //item[2] return $n/@v")      # ['5']
    doc.getroot().xpath("(//item ! string(.)) => count()")        # 2.0

    style = XSLT("""<xsl:stylesheet version="3.0"
        xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
      <xsl:mode use-accumulators="depth"/>
      <xsl:accumulator name="depth" initial-value="0">
        <xsl:accumulator-rule match="*" phase="start" select="$value + 1"/>
        <xsl:accumulator-rule match="*" phase="end" select="$value - 1"/>
      </xsl:accumulator>
      <xsl:template match="/"><o>
        <xsl:iterate select="//item">
          <i d="{accumulator-before('depth')}"/>
        </xsl:iterate>
      </o></xsl:template>
    </xsl:stylesheet>""")
    print(tostring(style(doc), encoding="unicode"))
    # <o><i d="2"/><i d="2"/></o>   # items sit at depth 2 (r → item)

Unsupported constructs fail at XSLT() compile time or at evaluation with LeptrisError — except two instructions that still produce empty output instead of an error (xsl:map/xsl:map-entry, and xsl:value-of/@separator is ignored); tracked in the #685/#690 ledgers above.

HTML parsing

leptris.html (libleptris 1.9.75+) — tolerant HTML in the shape of lxml's etree.HTMLParser: implied end tags, void elements, case-insensitive names, unquoted attributes, the named-entity table, and a synthesized <html>/<head>/<body> wrapper:

from leptris import html

r = html.fromstring("<p>hello <b>world")   # <html><head/><body><p>hello <b>world</b></p></body></html>
with html.document("<td>c") as doc:
    doc.xpath("count(//td)")               # 1.0

Since libleptris 1.9.76 the output is byte-exact with lxml's etree.HTMLParser (minimized attributes are empty strings; no empty <head/> is emitted) — leptris/leptris#813.

Migrating from lxml

lxml leptris Notes
etree.fromstring / etree.XML fromstring / XML
etree.parse parse paths and file-likes; no URLs
etree.tostring(elem, …) tostring(elem, …) bytes by default, encoding="unicode" for str
elem.tag / .text / .tail same tag uses {uri}local Clark notation; CDATA merges into text (lxml's default parser behavior)
elem.attrib / .get() / .keys() / .items() same attrib is a read-only Mapping
elem.getparent/getnext/getprevious same
elem[i], len(elem), iteration, slices same indexing is child indexing, never attribute lookup
elem.iter() / .iterdescendants() / .itertext() same elements only (ElementTree semantics); lxml's iter() also yields comments/PIs
elem.find/findall/findtext same accepts full XPath 1.0 — a superset of ElementPath — including {uri}local names
elem.xpath(expr, namespaces=…) same plus variables={…} (leptris extension)
etree.c14n / etree.XInclude c14n(…) / doc.process_xinclude()
etree.XMLSyntaxError ParseError XPath failures raise XPathError; both subclass LeptrisError
etree.Element, SubElement, append, set, remove not exposed libleptris has partial mutation upstream (node content setters, set_root, remove_children) — not surfaced here; build trees elsewhere
document-level comments / PIs doc.toplevel_comments() / doc.toplevel_pis() prolog then epilog; requires libleptris 1.9.3+
etree.iterparse leptris.iterparse(source, full_document=False) bounded by the largest subtree; yields ("end", element); elements borrowed until the next yield; tags resolve namespaces (Clark notation, libleptris 1.9.4+). Truncated or malformed input raises ParseError (both modes, libleptris 1.9.15+). full_document=True yields every element in completion order
smart strings plain str XPath string/attribute results
elem.nsmap absent use elem.namespace / elem.prefix and xpath(namespaces=…)
etree.XPath compiled objects leptris.XPath(expression) compile once, evaluate many; contexts, namespaces, and variables supported
etree.XSLT leptris.XSLT(stylesheet) compile once, apply to any Document — see the version support matrix above
parser options (resolve_entities, …) absent libleptris 1.2.0 has no per-parse options
elem.sourceline same requires libleptris 1.3.0+
undeclared XPath prefix raises in lxml evaluates to an empty nodeset here
ATTLIST default attributes applied by lxml's default parser excluded by default (ElementTree-like; XML 1.0 §5 permits either) — Document.parse(xml, attribute_defaults=True) opts in
declared non-UTF-8 bytes (UTF-16, latin-1, …) auto-detected auto-detected — declared encodings route through the converter, others retry on failure (libleptris 1.9.15+)
parser options (remove_blank_text, …) etree.XMLParser(remove_blank_text=True) Document.parse(xml, remove_blank_text=True) — ~35% faster on pretty-printed input; also attribute_defaults=True, recover=True

Layout

  • leptris/_ffi.py — cdef mirror of the public headers + loader (the only place libleptris is declared)
  • leptris/_leptrisaccel.c — the C accelerator (abi3): allocates Elements and runs the hot accessors, subtree iteration, the parse and serialization seams, and the per-document element registry; bound to libleptris by the positional protocol in element.py
  • leptris/element.py, document.py, node.py, xpath.py — the Python surface: queries, walks, documents; node.py exposes the full DOM (comments, CDATA, PIs) beneath the ElementTree shape
  • leptris/api.py — fromstring/parse/tostring/c14n/ iterparse
  • leptris/sax.py — SAX one-shot and streaming
  • tests/ — pytest suite (pytest with LEPTRIS_LIB_PATH set)
  • benchmarks/ — matrix vs lxml/ElementTree/minidom (pip install .[bench], then python -m benchmarks.matrix)

Memory model

The Document owns the whole tree and its pool. Accessor strings are copied into Python str at the boundary, so nothing depends on document lifetime after a call returns. Elements keep a reference to their Document, so the pool cannot be freed while any wrapper is alive. Prefer explicit close() / the context manager; __del__ is a refcounting safety net, not a contract. Using an element after its document is closed raises LeptrisError.

Versioning

libleptris-version.txt pins the library release the binding is built and tested against. Since 1.9.76.0 the package version is {c-full-semver}.{patch} — the pinned libleptris version plus a binding-local patch counter: lib 1.9.76 → 1.9.76.0, then 1.9.76.1 for binding-only fixes against the same pin, resetting the patch whenever the pin moves. (1.2.0–1.27.1 were the interim own-semver line.) pyproject.toml and leptris/__init__.py must agree at release time.

Publishing

Releases publish to PyPI via .github/workflows/release.yml, using PyPI trusted publishing (no stored credentials). The workflow runs on manual dispatch (ships the version in pyproject.toml) and is called by the libleptris release flow (publish: true), so every libleptris release ships the wheel.

Local development

python3 -m venv .venv
./.venv/bin/pip install --upgrade build pytest cffi
./.venv/bin/pip install -e .[test,bench]
LEPTRIS_LIB_PATH=/path/to/libleptris.dylib ./.venv/bin/python -m pytest tests/ -q

Project links

Data verified by PyPI on Sep 4, 2026
Data provided by the project maintainers, verified at the time the release was uploaded to PyPI.

Key dates

PyPI data
Data sourced directly from PyPI's database.
  • Released:
Newer release available (1.27.1)

1 maintainer

PyPI data
Data sourced directly from PyPI's database.
Avatar for leptris from gravatar.com leptris

Credits

Author: Ribose

GitHub Statistics

Data verified by PyPI on Sep 4, 2026
The GitHub source repository was provided by the project maintainers and verified by PyPI at the time of upload. Stars, forks, and open issues/PRs are derived from that repository and have not been independently verified.

License expression

MIT
View SPDX License List

Requires

Python >=3.9

Provides Extra

test bench

Tags

xml xpath parser lxml ffi cffi

Classifiers

Report project as malware

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

leptris-1.9.80.0.tar.gz (69.1 kB view details)

Uploaded Source

Built Distributions

If you're not sure about the file name format, learn more about wheel file names.

leptris-1.9.80.0-cp39-abi3-win_amd64.whl (49.3 kB view details)

Uploaded CPython 3.9+Windows x86-64

leptris-1.9.80.0-cp39-abi3-manylinux_2_17_aarch64.manylinux2014_aarch64.whl (105.6 kB view details)

Uploaded CPython 3.9+manylinux: glibc 2.17+ ARM64

leptris-1.9.80.0-cp39-abi3-manylinux_2_5_x86_64.manylinux1_x86_64.manylinux_2_17_x86_64.manylinux2014_x86_64.whl (101.6 kB view details)

Uploaded CPython 3.9+manylinux: glibc 2.17+ x86-64manylinux: glibc 2.5+ x86-64

leptris-1.9.80.0-cp39-abi3-macosx_11_0_arm64.whl (47.7 kB view details)

Uploaded CPython 3.9+macOS 11.0+ ARM64

leptris-1.9.80.0-cp39-abi3-macosx_10_9_x86_64.whl (47.1 kB view details)

Uploaded CPython 3.9+macOS 10.9+ x86-64

File details

Details for the file leptris-1.9.80.0.tar.gz.

File metadata

  • Download URL: leptris-1.9.80.0.tar.gz
  • Upload date:
  • Size: 69.1 kB
  • Tags: Source
  • Uploaded using Trusted Publishing? Yes
  • Uploaded via: twine/7.0.0 CPython/3.13.14

File hashes

Hashes for leptris-1.9.80.0.tar.gz
Algorithm Hash digest
SHA256 48a9f287a6ad0d62614fd3827f06eab80bdf5b80b56f5f9832a07ffbf825ca95
MD5 bb85ec4ccdd0fd4b632f8b81f6eb324e
BLAKE2b-256 781f2ac57a2579ca17085157f25419145da66478c3478c00acda04d5ebac21e2

See more details on using hashes here.

Provenance

The following attestation bundles were made for leptris-1.9.80.0.tar.gz:

Publisher: release.yml on leptris/leptris-py

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file leptris-1.9.80.0-cp39-abi3-win_amd64.whl.

File metadata

  • Download URL: leptris-1.9.80.0-cp39-abi3-win_amd64.whl
  • Upload date:
  • Size: 49.3 kB
  • Tags: CPython 3.9+, Windows x86-64
  • Uploaded using Trusted Publishing? Yes
  • Uploaded via: twine/7.0.0 CPython/3.13.14

File hashes

Hashes for leptris-1.9.80.0-cp39-abi3-win_amd64.whl
Algorithm Hash digest
SHA256 04f09279285682eeb96ae621d80370d9119690eb65173a7b5f0baaa33038e067
MD5 44c4f19b5910a93b747054551a4dbaab
BLAKE2b-256 65e9ca23ccc54becd7072b72dba875e95406caca3e3a0b5c7c3b44efb621290e

See more details on using hashes here.

Provenance

The following attestation bundles were made for leptris-1.9.80.0-cp39-abi3-win_amd64.whl:

Publisher: release.yml on leptris/leptris-py

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file leptris-1.9.80.0-cp39-abi3-manylinux_2_17_aarch64.manylinux2014_aarch64.whl.

File metadata

File hashes

Hashes for leptris-1.9.80.0-cp39-abi3-manylinux_2_17_aarch64.manylinux2014_aarch64.whl
Algorithm Hash digest
SHA256 b923e7e30b3e63c965ca5c96e53f21d2b14c4a64b9f333f8019baad8094d5777
MD5 8f1dfba2395aeab2c2d2e914620dae9a
BLAKE2b-256 e7f1332c385662ee6cd8c62eb9e37f8e6e3bcfbce3294dfe5603ad30ec7fe46d

See more details on using hashes here.

Provenance

The following attestation bundles were made for leptris-1.9.80.0-cp39-abi3-manylinux_2_17_aarch64.manylinux2014_aarch64.whl:

Publisher: release.yml on leptris/leptris-py

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file leptris-1.9.80.0-cp39-abi3-manylinux_2_5_x86_64.manylinux1_x86_64.manylinux_2_17_x86_64.manylinux2014_x86_64.whl.

File metadata

File hashes

Hashes for leptris-1.9.80.0-cp39-abi3-manylinux_2_5_x86_64.manylinux1_x86_64.manylinux_2_17_x86_64.manylinux2014_x86_64.whl
Algorithm Hash digest
SHA256 1f39e13d9f9f89cda8b9ddc6a8bdc32c0d89f3d83d8d246a39c58d78ff0a2945
MD5 16bb9a7ac2b6097d377d48977d5371cf
BLAKE2b-256 a5a74473dcba29381396bbcff17a62a9b328e0538484ab75f4ce31e5c9125ab1

See more details on using hashes here.

Provenance

The following attestation bundles were made for leptris-1.9.80.0-cp39-abi3-manylinux_2_5_x86_64.manylinux1_x86_64.manylinux_2_17_x86_64.manylinux2014_x86_64.whl:

Publisher: release.yml on leptris/leptris-py

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file leptris-1.9.80.0-cp39-abi3-macosx_11_0_arm64.whl.

File metadata

File hashes

Hashes for leptris-1.9.80.0-cp39-abi3-macosx_11_0_arm64.whl
Algorithm Hash digest
SHA256 2b81acbacbb176512bd30db2f51579261344d80a865137b65fa22963369acc27
MD5 f7323d0265af627334aec5a9154eec3e
BLAKE2b-256 f6993f04779ff325e79ffb2740cf0b81858fce17bb5ef24106e5bcb7484c0202

See more details on using hashes here.

Provenance

The following attestation bundles were made for leptris-1.9.80.0-cp39-abi3-macosx_11_0_arm64.whl:

Publisher: release.yml on leptris/leptris-py

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file leptris-1.9.80.0-cp39-abi3-macosx_10_9_x86_64.whl.

File metadata

File hashes

Hashes for leptris-1.9.80.0-cp39-abi3-macosx_10_9_x86_64.whl
Algorithm Hash digest
SHA256 d04c826ae53a5dc18d7b1239f69270691362c14d1dc466f98edf83775da4f29a
MD5 e4b15d483480d4e7ae06287c0ca77c4a
BLAKE2b-256 bbf25b421ae002f38e0f3dbb533c5659edbdb893c1bebba100ceb42b0b9b790c

See more details on using hashes here.

Provenance

The following attestation bundles were made for leptris-1.9.80.0-cp39-abi3-macosx_10_9_x86_64.whl:

Publisher: release.yml on leptris/leptris-py

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

Release history Release notifications | RSS feed

1.27.1

6 files

1.27.0

6 files

1.26.1

6 files

1.26.0

6 files

1.25.4

6 files

1.25.3

6 files

1.25.2

6 files

1.25.1

6 files

1.25.0

6 files

1.24.3

6 files

1.24.2

6 files

1.24.1

6 files

1.24.0

6 files

1.23.3

6 files

1.23.2

6 files

1.23.1

6 files

1.23.0

6 files

1.22.2

6 files

1.22.1

6 files

1.22.0

6 files

1.21.0

6 files

1.20.0

6 files

1.19.0

6 files

1.18.0

6 files

1.17.1

6 files

1.17.0

6 files

1.16.1

6 files

1.16.0

6 files

1.15.1

6 files

1.15.0

6 files

1.14.3

6 files

1.14.2

6 files

1.14.1

6 files

1.14.0

6 files

1.13.3

6 files

1.13.2

6 files

1.13.1

6 files

1.13.0

6 files

1.12.0

6 files

1.11.1

6 files

1.11.0

6 files

1.10.0

6 files

1.9.93.2

6 files

1.9.93.0

6 files

1.9.90.0

6 files

1.9.87.0

6 files

1.9.86.0

6 files

1.9.84.0

6 files

1.9.83.0

6 files

This release

1.9.80.0 This release

6 files

1.9.79.0

6 files

1.9.76.0

6 files

1.9.0

6 files

1.8.0

6 files

1.7.0

6 files

1.6.1

6 files

1.6.0

5 files

1.5.0

2 files

1.4.1

2 files

1.4.0

2 files

1.3.1

2 files

1.3.0

2 files

1.2.0

2 files

Anthropic, PBC Visionary sponsor Bloomberg Visionary sponsor Hudson River Trading Visionary sponsor Meta Visionary sponsor NVIDIA Visionary sponsor Microsoft Sustainability sponsor Depot Continuous Integration AWS Cloud computing and Security Sponsor Datadog Monitoring Fastly CDN Google Download Analytics Sentry Error logging StatusPage Status page