"latin_1" encoding unknown on Windows

[Lukas Schreiber]

I just migrated a project from Linux to Windows 10. Here `etree.iterparse(path, remove_blank_text=True, encoding="latin_1")` raises `LookupError: unknown encoding: 'b'latin_1''`.

Since the docs don't specify what strings are accepted for encodings, I assumed using the spelling from the codecs standard library would work. But it didn't. Neither does lxml find `"latin-1"` (with a hyphen). Setting the encoding to `"latin1"` solved my problem. However this is not satisfactory, as I couldn't find any guidance on how to spell the encoding or even what encodings are supported. I've spent more than an hour searching.

Python : sys.version_info(major=3, minor=9, micro=7, releaselevel='final', serial=0)
lxml.etree : (4, 9, 1, 0)
libxml used : (2, 10, 3)
libxml compiled : (2, 9, 14)
libxslt used : (1, 1, 37)
libxslt compiled : (1, 1, 35)

[Hugo Bauer (hugoobauer)]

I have the same issue from a Python:3.10 Docker image, but not from my laptop (macOS).

>>> import lxml.html
>>> lxml.html.HTMLParser(encoding='latin_1')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.10/site-packages/lxml/html/__init__.py", line 1910, in __init__
    super(HTMLParser, self).__init__(**kwargs)
  File "src/lxml/parser.pxi", line 1728, in lxml.etree.HTMLParser.__init__
  File "src/lxml/parser.pxi", line 840, in lxml.etree._BaseParser.__init__
LookupError: unknown encoding: 'b'latin_1''