Repository: scrapy/parsel

Issue:
LookupError: unknown encoding: 'b'utf8''
Installed using conda on Windows 11 machine.  Working through the tutorial and 

response.css("title")

Gives this error:

  File "src\\lxml\\parser.pxi", line 1806, in lxml.etree.HTMLParser.__init__
  File "src\\lxml\\parser.pxi", line 858, in lxml.etree._BaseParser.__init__
LookupError: unknown encoding: 'b'utf8''

scrapy                    2.12.0          py311h1ea47a8_1    conda-forge
twisted                   23.10.0         py311haa95532_0
lxml                      5.2.1           py311h395c83e_1

Hints from issue comments:
@Gallaecio: Could you provide the entire spider code that produces the error, and the entire traceback? (of which you shared the 3 last lines)@jh-rheinhardt: ```python
from pathlib import Path

import scrapy


class QuotesSpider(scrapy.Spider):
    name = "quotes"
    start_urls = [
        "https://quotes.toscrape.com/page/1/",
        "https://quotes.toscrape.com/page/2/",
    ]

    def parse(self, response):
        page = response.url.split("/")[-2]
        filename = f"quotes-{page}.html"
        Path(filename).write_bytes(response.body)
```

```shell
\> scrapy shell "https://quotes.toscrape.com/page/1/"
```

```python
>>>response.css("title")


Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "C:\...\anaconda3\envs\WebScraping\Lib\site-packages\scrapy\http\response\text.py", line 168, in css
    return cast(SelectorList, self.selector.css(query))
                              ^^^^^^^^^^^^^
  File "C:\...\anaconda3\envs\WebScraping\Lib\site-packages\scrapy\http\response\text.py", line 147, in selector
    self._cached_selector = Selector(self)
                            ^^^^^^^^^^^^^^
  File "C:\...\anaconda3\envs\WebScraping\Lib\site-packages\scrapy\selector\unified.py", line 102, in __init__
    super().__init__(text=text, type=st, **kwargs)
  File "C:\...\anaconda3\envs\WebScraping\Lib\site-packages\parsel\selector.py", line 496, in __init__
    root, type = _get_root_and_type_from_text(
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\...\anaconda3\envs\WebScraping\Lib\site-packages\parsel\selector.py", line 377, in _get_root_and_type_from_text
    root = _get_root_from_text(text, type=type, **lxml_kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\...\anaconda3\envs\WebScraping\Lib\site-packages\parsel\selector.py", line 329, in _get_root_from_text
    return create_root_node(text, _ctgroup[type]["_parser"], **lxml_kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\...\anaconda3\envs\WebScraping\Lib\site-packages\parsel\selector.py", line 110, in create_root_node
    parser = parser_cls(recover=True, encoding=encoding, huge_tree=True)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\...\anaconda3\envs\WebScraping\Lib\site-packages\lxml\html\__init__.py", line 1887, in __init__
    super().__init__(**kwargs)
  File "src\\lxml\\parser.pxi", line 1806, in lxml.etree.HTMLParser.__init__
  File "src\\lxml\\parser.pxi", line 858, in lxml.etree._BaseParser.__init__
LookupError: unknown encoding: 'b'utf8''
```@Gallaecio: I cannot reproduce the issue with Scrapy 2.12:

```bash
$ scrapy shell "https://quotes.toscrape.com/page/1/"
2024-11-21 12:36:57 [scrapy.utils.log] INFO: Scrapy 2.12.0 started (bot: scrapybot)
2024-11-21 12:36:57 [scrapy.utils.log] INFO: Versions: lxml 5.3.0.0, libxml2 2.12.9, cssselect 1.2.0, parsel 1.9.1, w3lib 2.2.1, Twisted 24.10.0, Python 3.12.7 (main, Oct  1 2024, 11:15:50) [GCC 14.2.1 20240910], pyOpenSSL 24.2.1 (OpenSSL 3.3.2 3 Sep 2024), cryptography 43.0.3, Platform Linux-6.11.8-zen1-2-zen-x86_64-with-glibc2.40
2024-11-21 12:36:57 [scrapy.addons] INFO: Enabled addons:
[]
2024-11-21 12:36:57 [scrapy.utils.log] DEBUG: Using reactor: twisted.internet.epollreactor.EPollReactor
2024-11-21 12:36:57 [scrapy.extensions.telnet] INFO: Telnet Password: 7f709a2a4ad7bf38
2024-11-21 12:36:57 [scrapy.middleware] INFO: Enabled extensions:
['scrapy.extensions.corestats.CoreStats',
 'scrapy.extensions.telnet.TelnetConsole',
 'scrapy.extensions.memusage.MemoryUsage']
2024-11-21 12:36:57 [scrapy.crawler] INFO: Overridden settings:
{'DUPEFILTER_CLASS': 'scrapy.dupefilters.BaseDupeFilter',
 'LOGSTATS_INTERVAL': 0}
2024-11-21 12:36:57 [scrapy.middleware] INFO: Enabled downloader middlewares:
['scrapy.downloadermiddlewares.offsite.OffsiteMiddleware',
 'scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware',
 'scrapy.downloadermiddlewares.downloadtimeout.DownloadTimeoutMiddleware',
 'scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware',
 'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware',
 'scrapy.downloadermiddlewares.retry.RetryMiddleware',
 'scrapy.downloadermiddlewares.redirect.MetaRefreshMiddleware',
 'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware',
 'scrapy.downloadermiddlewares.redirect.RedirectMiddleware',
 'scrapy.downloadermiddlewares.cookies.CookiesMiddleware',
 'scrapy.downloadermiddlewares.httpproxy.HttpProxyMiddleware',
 'scrapy.downloadermiddlewares.stats.DownloaderStats']
2024-11-21 12:36:57 [scrapy.middleware] INFO: Enabled spider middlewares:
['scrapy.spidermiddlewares.httperror.HttpErrorMiddleware',
 'scrapy.spidermiddlewares.referer.RefererMiddleware',
 'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware',
 'scrapy.spidermiddlewares.depth.DepthMiddleware']
2024-11-21 12:36:57 [scrapy.middleware] INFO: Enabled item pipelines:
[]
2024-11-21 12:36:57 [scrapy.extensions.telnet] INFO: Telnet console listening on 127.0.0.1:6023
2024-11-21 12:36:57 [scrapy.core.engine] INFO: Spider opened
2024-11-21 12:37:02 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://quotes.toscrape.com/page/1/> (referer: None)
[s] Available Scrapy objects:
[s]   scrapy     scrapy module (contains scrapy.Request, scrapy.Selector, etc)
[s]   crawler    <scrapy.crawler.Crawler object at 0x7fc7dbb220c0>
[s]   item       {}
[s]   request    <GET https://quotes.toscrape.com/page/1/>
[s]   response   <200 https://quotes.toscrape.com/page/1/>
[s]   settings   <scrapy.settings.Settings object at 0x7fc7dbad0290>
[s]   spider     <DefaultSpider 'default' at 0x7fc7db60dbb0>
[s] Useful shortcuts:
[s]   fetch(url[, redirect=True]) Fetch URL and update local objects (by default, redirects are followed)
[s]   fetch(req)                  Fetch a scrapy.Request and update local objects 
[s]   shelp()           Shell help (print this help)
[s]   view(response)    View response in a browser
>>> response.css("title")
[<Selector query='descendant-or-self::title' data='<title>Quotes to Scrape</title>'>]
```

When using `scrapy shell`, your spider code should be irrelevant. I’m using Linux, but the traceback does not look OS-specific. It is about something like `str(b'utf-8')` being passed as encoding somewhere (that’s how you would end up with `'b'utf8''`). But I find it hard to believe that it happens with the latest versions of Scrapy and parsel without any encoding-related user input.

In any case, I cannot reproduce the issue with the provided code.

Please, try upgrading parsel and Scrapy and try again.

If the problem persists, see if you can reproduce the issue installing Scrapy with a Python virtual environment instead of using conda.@wRAR: > ensure the Venv you are running on is using python 3.9

This makes no sense.@kourosh-amiri-sani: Sorry. Basically I ran these commands in the anaconda prompt window:


```python
conda create -n scrapy_env python=3.9 -y
conda activate scrapy_env
pip install scrapy
``` 


@wRAR: Sure, and that "fix" doesn't make sense to me (please also note that 3.9 is EOL in a year).@kourosh-amiri-sani: ok looked into it, you are right. The problem is actually just using the base environment in anaconda not the python version. @ChrMosau: I have the same situation as @jh-rheinhardt . I installed scrapy via `conda-forge` on a Windows 11 system and got the same error. 

I tested a second environment (inspired by @kourosh-amiri-sani ) where I did not install scrapy directly when creating the environment (i.e. without conda-forge), but via pip after activating the environment and it worked.@wRAR: There are two problems here. First, the incorrect bytes->str conversion in lxml when printing the error message (and only then). Second, ~~lxml~~libxml2 in conda(?) not knowing the `utf8` encoding (as opposed to e.g. `utf-8`).@wRAR: The default encoding in [`parsel.selector.create_root_node()`](https://github.com/scrapy/parsel/blob/05f0435287732538b619fbec94f1f572cbcfb8c7/parsel/selector.py#L93) is `"utf8"` (since that code was added in 2012). lxml (in [`lxml.etree._BaseParser.__init__()`](https://github.com/lxml/lxml/blob/7be20eb3931010b42dfa81427c45fa716f52954c/src/lxml/parser.pxi#L856) passes that directly to libxml2's `xmlFindCharEncodingHandler()` and the result [apparently depends on various things we can't control](https://stackoverflow.com/a/57756025/113586). 

While we could change this to some safer default (`"utf-8"` probably), I'm not sure what's the correct robust way to do this. Note that we also use the same `encoding` argument in `str.encode()`.@Gallaecio: > While we could change this to some safer default (`"utf-8"` probably)

:+1: @longlong211: change the env@easonchiu0327: I had this issue while using scrapy, but it fixed after upgrading the version of scrapy, python, selenium, twisted and parsel.
I don't know why, but it works pretty well after that.


Solution patch:
diff --git a/parsel/selector.py b/parsel/selector.py
index b37adbd..8250e06 100644
--- a/parsel/selector.py
+++ b/parsel/selector.py
@@ -90,7 +90,7 @@ def create_root_node(
     base_url: Optional[str] = None,
     huge_tree: bool = LXML_SUPPORTS_HUGE_TREE,
     body: bytes = b"",
-    encoding: str = "utf8",
+    encoding: str = "utf-8",
 ) -> etree._Element:
     """Create root node for text using given parser class."""
     if not text:
@@ -318,7 +318,7 @@ def _get_root_and_type_from_bytes(
 ) -> Tuple[Any, str]:
     if input_type == "text":
         return body.decode(encoding), input_type
-    if encoding == "utf8":
+    if encoding == "utf-8":
         try:
             data = json.load(BytesIO(body))
         except ValueError:
@@ -445,7 +445,7 @@ def __init__(
         text: Optional[str] = None,
         type: Optional[str] = None,
         body: bytes = b"",
-        encoding: str = "utf8",
+        encoding: str = "utf-8",
         namespaces: Optional[Mapping[str, str]] = None,
         root: Optional[Any] = _NOT_SET,
         base_url: Optional[str] = None,
@@ -518,7 +518,7 @@ def _get_root(
         huge_tree: bool = LXML_SUPPORTS_HUGE_TREE,
         type: Optional[str] = None,
         body: bytes = b"",
-        encoding: str = "utf8",
+        encoding: str = "utf-8",
     ) -> etree._Element:
         return create_root_node(
             text,


Test patch:
diff --git a/tests/test_selector.py b/tests/test_selector.py
index 96713f9..d2a1641 100644
--- a/tests/test_selector.py
+++ b/tests/test_selector.py
@@ -1346,7 +1346,7 @@ def __init__(
         text: Optional[str] = None,
         type: Optional[str] = None,
         body: bytes = b"",
-        encoding: str = "utf8",
+        encoding: str = "utf-8",
         namespaces: Optional[Mapping[str, str]] = None,
         root: Optional[Any] = _NOT_SET,
         base_url: Optional[str] = None,
diff --git a/tests/test_selector_csstranslator.py b/tests/test_selector_csstranslator.py
index 2adc2f5..93cc7ca 100644
--- a/tests/test_selector_csstranslator.py
+++ b/tests/test_selector_csstranslator.py
@@ -227,4 +227,4 @@ def test_pseudoclass_has(self) -> None:
 
 class CSSSelectorTestBytes(CSSSelectorTest):
     def setUp(self) -> None:
-        self.sel = self.sscls(body=bytes(HTMLBODY, encoding="utf8"))
+        self.sel = self.sscls(body=bytes(HTMLBODY, encoding="utf-8"))