DOC: Clean up redirects & dead links

doc/source/development/code_style.rst

@@ -28,7 +28,7 @@ Testing
 Failing tests
 --------------
 
-See https://docs.pytest.org/en/latest/skipping.html for background.
+See https://docs.pytest.org/en/latest/how-to/skipping.html for background.
 
 Do not use ``pytest.xfail``
 ---------------------------

doc/source/development/contributing_codebase.rst

@@ -155,7 +155,7 @@ Python (PEP8 / black)
 
 pandas follows the `PEP8 <https://www.python.org/dev/peps/pep-0008/>`_ standard
 and uses `Black <https://black.readthedocs.io/en/stable/>`_ and
-`Flake8 <http://flake8.pycqa.org/en/latest/>`_ to ensure a consistent code
+`Flake8 <https://flake8.pycqa.org/en/latest/>`_ to ensure a consistent code
 format throughout the project. We encourage you to use :ref:`pre-commit <contributing.pre-commit>`.
 
 :ref:`Continuous Integration <contributing.ci>` will run those tools and
@@ -204,7 +204,7 @@ Import formatting
 pandas uses `isort <https://pypi.org/project/isort/>`__ to standardise import
 formatting across the codebase.
 
-A guide to import layout as per pep8 can be found `here <https://www.python.org/dev/peps/pep-0008/#imports/>`__.
+A guide to import layout as per pep8 can be found `here <https://www.python.org/dev/peps/pep-0008/#imports>`__.
 
 A summary of our current import sections ( in order ):
 
@@ -449,7 +449,7 @@ continuous integration services, once your pull request is submitted.
 However, if you wish to run the test suite on a branch prior to submitting the pull request,
 then the continuous integration services need to be hooked to your GitHub repository. Instructions are here
 for `GitHub Actions <https://docs.github.com/en/actions/>`__ and
-`Azure Pipelines <https://docs.microsoft.com/en-us/azure/devops/pipelines/>`__.
+`Azure Pipelines <https://docs.microsoft.com/en-us/azure/devops/pipelines/?view=azure-devops>`__.
 
 A pull-request will be considered for merging when you have an all 'green' build. If any tests are failing,
 then you will get a red 'X', where you can click through to see the individual failed tests.
@@ -777,18 +777,18 @@ Running the performance test suite
 
 Performance matters and it is worth considering whether your code has introduced
 performance regressions. pandas is in the process of migrating to
-`asv benchmarks <https://github.com/spacetelescope/asv>`__
+`asv benchmarks <https://github.com/airspeed-velocity/asv>`__
 to enable easy monitoring of the performance of critical pandas operations.
 These benchmarks are all found in the ``pandas/asv_bench`` directory, and the
-test results can be found `here <https://pandas.pydata.org/speed/pandas/#/>`__.
+test results can be found `here <https://pandas.pydata.org/speed/pandas/>`__.
 
 To use all features of asv, you will need either ``conda`` or
 ``virtualenv``. For more details please check the `asv installation
 webpage <https://asv.readthedocs.io/en/latest/installing.html>`_.
 
 To install asv::
 
-    pip install git+https://github.com/spacetelescope/asv
+    pip install git+https://github.com/airspeed-velocity/asv
 
 If you need to run a benchmark, change your directory to ``asv_bench/`` and run::
 

doc/source/development/contributing_environment.rst

@@ -82,7 +82,7 @@ You will need `Build Tools for Visual Studio 2019
 	In the installer, select the "C++ build tools" workload.
 
 You can install the necessary components on the commandline using
-`vs_buildtools.exe <https://aka.ms/vs/16/release/vs_buildtools.exe>`_:
+`vs_buildtools.exe <https://download.visualstudio.microsoft.com/download/pr/9a26f37e-6001-429b-a5db-c5455b93953c/460d80ab276046de2455a4115cc4e2f1e6529c9e6cb99501844ecafd16c619c4/vs_BuildTools.exe>`_:
 
 .. code::
 
@@ -138,8 +138,8 @@ Creating a Python environment
 
 Now create an isolated pandas development environment:
 
-* Install either `Anaconda <https://www.anaconda.com/download/>`_, `miniconda
-  <https://conda.io/miniconda.html>`_, or `miniforge <https://github.com/conda-forge/miniforge>`_
+* Install either `Anaconda <https://www.anaconda.com/products/individual>`_, `miniconda
+  <https://docs.conda.io/en/latest/miniconda.html>`_, or `miniforge <https://github.com/conda-forge/miniforge>`_
 * Make sure your conda is up to date (``conda update conda``)
 * Make sure that you have :any:`cloned the repository <contributing.forking>`
 * ``cd`` to the pandas source directory
@@ -181,7 +181,7 @@ To return to your root environment::
 
       conda deactivate
 
-See the full conda docs `here <https://conda.pydata.org/docs>`__.
+See the full conda docs `here <https://conda.io/projects/conda/en/latest/>`__.
 
 
 Creating a Python environment (pip)
@@ -238,7 +238,7 @@ Consult the docs for setting up pyenv `here <https://github.com/pyenv/pyenv>`__.
 
 Below is a brief overview on how to set-up a virtual environment with Powershell
 under Windows. For details please refer to the
-`official virtualenv user guide <https://virtualenv.pypa.io/en/stable/userguide/#activate-script>`__
+`official virtualenv user guide <https://virtualenv.pypa.io/en/latest/user_guide.html#activators>`__
 
 Use an ENV_DIR of your choice. We'll use ~\\virtualenvs\\pandas-dev where
 '~' is the folder pointed to by either $env:USERPROFILE (Powershell) or

doc/source/development/debugging_extensions.rst

@@ -80,7 +80,7 @@ Once the process launches, simply type ``run`` and the test suite will begin, st
 Checking memory leaks with valgrind
 ===================================
 
-You can use `Valgrind <https://www.valgrind.org>`_ to check for and log memory leaks in extensions. For instance, to check for a memory leak in a test from the suite you can run:
+You can use `Valgrind <https://valgrind.org/>`_ to check for and log memory leaks in extensions. For instance, to check for a memory leak in a test from the suite you can run:
 
 .. code-block:: sh
 

doc/source/development/extending.rst

@@ -468,7 +468,7 @@ This would be more or less equivalent to:
 The backend module can then use other visualization tools (Bokeh, Altair,...)
 to generate the plots.
 
-Libraries implementing the plotting backend should use `entry points <https://setuptools.readthedocs.io/en/latest/setuptools.html#dynamic-discovery-of-services-and-plugins>`__
+Libraries implementing the plotting backend should use `entry points <https://setuptools.pypa.io/en/latest/userguide/entry_point.html>`__
 to make their backend discoverable to pandas. The key is ``"pandas_plotting_backends"``. For example, pandas
 registers the default "matplotlib" backend as follows.
 

doc/source/development/maintaining.rst

@@ -237,4 +237,4 @@ a milestone before tagging, you can request the bot to backport it with:
 
 
 .. _governance documents: https://github.com/pandas-dev/pandas-governance
-.. _list of permissions: https://help.github.com/en/github/setting-up-and-managing-organizations-and-teams/repository-permission-levels-for-an-organization
+.. _list of permissions: https://docs.github.com/en/organizations/managing-access-to-your-organizations-repositories/repository-roles-for-an-organization

doc/source/development/roadmap.rst

@@ -205,4 +205,4 @@ We improved the pandas documentation
 * :ref:`getting_started` contains a number of resources intended for new
   pandas users coming from a variety of backgrounds (:issue:`26831`).
 
-.. _pydata-sphinx-theme: https://github.com/pandas-dev/pydata-sphinx-theme
+.. _pydata-sphinx-theme: https://github.com/pydata/pydata-sphinx-theme