Update lxml to 4.0.0

[pyup-bot]

There's a new version of lxml available.
You are currently using 3.7.2. I have updated it to 4.0.0

These links might come in handy: PyPI | Changelog | Homepage | Bugtracker

Changelog

4.0.0

==================

Features added

• The ElementPath implementation is now compiled using Cython,
  which speeds up the .find*() methods quite significantly.

• The modules lxml.builder, lxml.html.diff and lxml.html.clean
  are also compiled using Cython in order to speed them up.

• xmlfile() supports async coroutines using async with and await.

• iterwalk() has a new method skip_subtree() that prevents walking into
  the descendants of the current element.

• RelaxNG.from_rnc_string() accepts a base_url argument to
  allow relative resource lookups.

• The XSLT result object has a new method .write_output(file) that serialises
  output data into a file according to the <xsl:output> configuration.

Bugs fixed

• GH251: HTML comments were handled incorrectly by the soupparser.
  Patch by mozbugbox.

• LP1654544: The html5parser no longer passes the useChardet option
  if the input is a Unicode string, unless explicitly requested. When parsing
  files, the default is to enable it when a URL or file path is passed (because
  the file is then opened in binary mode), and to disable it when reading from
  a file(-like) object.

Note: This is a backwards incompatible change of the default configuration.
If your code parses byte strings/streams and depends on character detection,
please pass the option guess_charset=True explicitly, which already worked
in older lxml versions.

• LP1703810: etree.fromstring() failed to parse UTF-32 data with BOM.

• LP1526522: Some RelaxNG errors were not reported in the error log.

• LP1567526: Empty and plain text input raised a TypeError in soupparser.

• LP1710429: Uninitialised variable usage in HTML diff.

• LP1415643: The closing tags context manager in xmlfile() could continue
  to output end tags even after writing failed with an exception.

• LP1465357: xmlfile.write() now accepts and ignores None as input argument.

• Compilation under Py3.7-pre failed due to a modified function signature.

Other changes

• The main module source files were renamed from lxml.*.pyx to plain
  *.pyx (e.g. etree.pyx) to simplify their handling in the build
  process. Care was taken to keep the old header files as fallbacks for
  code that compiles against the public C-API of lxml, but it might still
  be worth validating that third-party code does not notice this change.

3.8.0

==================

Features added

• ElementTree.write() has a new option doctype that writes out a
  doctype string before the serialisation, in the same way as tostring().

• GH220: xmlfile allows switching output methods at an element level.
  Patch by Burak Arslan.

• LP1595781, GH240: added a PyCapsule Python API and C-level API for
  passing externally generated libxml2 documents into lxml.

• GH244: error log entries have a new property path with an XPath
  expression (if known, None otherwise) that points to the tree element
  responsible for the error. Patch by Bob Kline.

• The namespace prefix mapping that can be used in ElementPath now injects
  a default namespace when passing a None prefix.

Bugs fixed

• GH238: Character escapes were not hex-encoded in the xmlfile serialiser.
  Patch by matejcik.

• GH229: fix for externally created XML documents. Patch by Theodore Dubois.

• LP1665241, GH228: Form data handling in lxml.html no longer strips the
  option values specified in form attributes but only the text values.
  Patch by Ashish Kulkarni.

• LP1551797: revert previous fix for XSLT error logging as it breaks
  multi-threaded XSLT processing.

• LP1673355, GH233: fromstring() html5parser failed to parse byte strings.

Other changes

• The previously undocumented docstring option in ElementTree.write()
  produces a deprecation warning and will eventually be removed.

3.7.4

==================

Bugs fixed

• LP1551797: revert previous fix for XSLT error logging as it breaks
  multi-threaded XSLT processing.

• LP1673355, GH233: fromstring() html5parser failed to parse byte strings.

3.7.3

==================

Bugs fixed

• GH218 was ineffective in Python 3.

• GH222: lxml.html.submit_form() failed in Python 3.
  Patch by Jakub Wilk.

Got merge conflicts? Close this PR and delete the branch. I'll create a new PR for you.

Happy merging! 🤖