Use a different library or function

Oct 13, 2025 by pynkocean.com 97 views

Introduction

When building a project using MkDocs, it can be frustrating to encounter errors that don't provide enough information to diagnose the issue. One such case is when the urllib.urlsplit function fails, resulting in a generic error message without any line number information. This can make it challenging to identify the root cause of the problem, especially when working with complex projects.

The Problem

In the case of a missing trailing slash in a URL, the urllib.urlsplit function can raise a ValueError exception. However, the error message doesn't provide any line number information, making it difficult to pinpoint the exact location of the issue.

Example Error Message

Here's an example error message that illustrates the problem:

DEBUG   -  [macros] - Rendering source page: path/to/file.md
DEBUG   -  [macros] - Page title: Some Title
DEBUG   -  Running `page_markdown` event from plugin 'table-reader'
ERROR   -  Error reading page 'path/to/file.md': Invalid IPv6 URL
Traceback (most recent call last):
  File "/Users/alexandra.magin/code/engineering-docs/.venv/bin/mkdocs", line 10, in <module>
    sys.exit(cli())
             ~~~^^
  File "/Users/alexandra.magin/code/engineering-docs/.venv/lib/python3.13/site-packages/click/core.py", line 1161, in __call__
    return self.main(*args, **kwargs)
           ~~~~~~~~~^^^^^^^^^^^^^^^^^
  File "/Users/alexandra.magin/code/engineering-docs/.venv/lib/python3.13/site-packages/click/core.py", line 1082, in main
    rv = self.invoke(ctx)
  File "/Users/alexandra.magin/code/engineering-docs/.venv/lib/python3.13/site-packages/click/core.py", line 1697, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
                           ~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^
  File "/Users/alexandra.magin/code/engineering-docs/.venv/lib/python3.13/site-packages/click/core.py", line 1443, in invoke
    return ctx.invoke(self.callback, **ctx.params)
           ~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/alexandra.magin/code/engineering-docs/.venv/lib/python3.13/site-packages/mkdocs/__main__.py", line 288, in build_command
    build.build(cfg, dirty=not clean)
    ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/alexandra.magin/code/engineering-docs/.venv/lib/python3.13/site-packages/mkdocs/commands/build.py", line 310, in build
    _populate_page(file.page, config, files, dirty)
    ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/alexandra.magin/code/engineering-docs/.venv/lib/python3.13/site-packages/mkdocs/commands/build.py", line 167, in _populate_page
    page.render(config, files)
    ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^
  File "/Users/alexandra.magin/code/engineering-docs/.venv/lib/python3.13/site-packages/mkdocs/structure/pages.py", line 285, in render
    self.content = md.convert(self.markdown)
                   ~~~~~~~~~~^^^^^^^^^^^^^^^
  File "/Users/alexandra.magin/code/engineering-docs/.venv/lib/python3.13/site-packages/markdown/core.py", line 361, in convert
    newRoot = treeprocessor.run(root)
  File "/Users/alexandra.magin/code/engineering-docs/.venv/lib/python3.13/site-packages/mkdocs/structure/pages.py", line 370, in run
    new_url = self.path_to_url(url)
  File "/Users/alexandra.magin/code/engineering-docs/.venv/lib/python3.13/site-packages/mkdocs/structure/pages.py", line 420, in path_to_url
    scheme, netloc, path, query, anchor = urlsplit(url)
                                          ~~~~~~~~^^^^^
  File "/Users/alexandra.magin/.local/share/uv/python/cpython-3.13.2-macos-aarch64-none/lib/python3.13/urllib/parse.py", line 514, in urlsplit
    raise ValueError("Invalid IPv6 URL")
ValueError: Invalid IPv6 URL

Diagnosing the Issue

In this example, the error message indicates that there's an issue with the urlsplit function, but it doesn't provide any line number information. To diagnose the issue, you'll need to examine the code and look for any potential problems with the URL.

Potential Solutions

One potential solution is to modify the urlsplit function to provide line number information. However, this would require changes to the urllib library, which may not be feasible.

Another potential solution is to use a different library or function to split the URL, such as the urlparse function from the urllib.parse module.

Conclusion

In conclusion, the lack of line number information in the error message can make it challenging to diagnose issues with the urllib.urlsplit function. While there are potential solutions to this problem, they may require modifications to the urllib library or the use of alternative libraries or functions.

Recommendations

If you encounter this issue, here are some recommendations:

Examine the code: Carefully examine the code to identify any potential problems with the URL.
Use a different library or function: Consider using a different library or function to split the URL, such as the urlparse function from the urllib.parse module.
Modify the urlsplit function: If you're comfortable with modifying the urllib library, you can try modifying the urlsplit function to provide line number information.

Q: What is the issue with the urllib.urlsplit function?

A: The issue with the urllib.urlsplit function is that it doesn't provide line number information when it fails. This can make it challenging to diagnose the issue, especially when working with complex projects.

Q: What is the error message that I might see when this issue occurs?

A: The error message that you might see when this issue occurs is a generic error message that indicates that there's an issue with the urlsplit function. However, it doesn't provide any line number information.

Q: How can I diagnose the issue with the urllib.urlsplit function?

A: To diagnose the issue with the urllib.urlsplit function, you'll need to examine the code and look for any potential problems with the URL. You can also try using a different library or function to split the URL, such as the urlparse function from the urllib.parse module.

Q: Can I modify the urllib.urlsplit function to provide line number information?

A: Yes, you can modify the urllib.urlsplit function to provide line number information. However, this would require changes to the urllib library, which may not be feasible.

Q: What are some potential solutions to this issue?

A: Some potential solutions to this issue include:

Using a different library or function to split the URL, such as the urlparse function from the urllib.parse module.
Modifying the urlsplit function to provide line number information.
Examining the code and looking for any potential problems with the URL.

Q: How can I prevent this issue from occurring in the future?

A: To prevent this issue from occurring in the future, you can:

Use a different library or function to split the URL, such as the urlparse function from the urllib.parse module.
Modify the urlsplit function to provide line number information.
Carefully examine the code and look for any potential problems with the URL.

Q: What are some best practices for working with URLs in Python?

A: Some best practices for working with URLs in Python include:

Using a consistent library or function to split the URL, such as the urlparse function from the urllib.parse module.
Carefully examining the code and looking for any potential problems with the URL.
Using a try-except block to catch any errors that may occur when working with URLs.

Q: Can I use a try-except block to catch any errors that may occur when working with URLs?

A: Yes, you can use a try-except block to catch any errors that may occur when working with URLs. This can help to prevent the program from crashing and provide more informative error messages.

Q: How can I use a try-except block to catch any errors that may occur when working with URLs?

A: To use a try-except block to catch any errors that may occur when working with URLs, you can use the following code:

try:
    # Code that may raise an error
    url = urllib.parse.urlparse("http://example.com")
except ValueError as e:
    # Handle the error
    print(f"Error: {e}")

By using a try-except block, you can catch any errors that may occur when working with URLs and provide more informative error messages.