MRG: Adding new variants to select the desired Qt binding (#12628)

Co-authored-by: Eric Larson <[email protected]>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

doc/changes/devel/12628.newfeature.rst

@@ -0,0 +1,4 @@
+We added new installation variants for a full installation with the PySide6 Qt binding
+(``"mne[full-pyside6]"``), with the PyQt6 binding (``"mne[full-pyqt6]"``, equivalent to
+``"mne[full]"``), and without any Qt binding (``"mne[full-no-qt]"``), which may be useful
+in certain situations by `Richard Höchenberger`_.

doc/install/advanced.rst

@@ -101,6 +101,18 @@ development version of MNE-Python. If you plan to contribute to MNE-Python, or
 just prefer to use git rather than pip to make frequent updates, there are
 instructions for installing from a ``git clone`` in the :ref:`contributing`.
 
+Choosing the Qt framework
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The ``conda-forge`` version of MNE-Python ships with PyQt5. If you would like to
+use a different binding, you can instead install MNE-Python via ``pip``:
+
+.. code-block:: console
+
+    $ pip install "mne[full]"          # uses PyQt6
+    $ pip install "mne[full-pyqt6]"    # same as above
+    $ pip install "mne[full-pyside6]"  # use PySide6
+    $ pip install "mne[full-no-qt]"    # don't install any Qt binding
 
 .. _CUDA:
 

pyproject.toml

@@ -59,11 +59,13 @@ data = []
 hdf5 = ["h5io", "pymatreader"]
 
 # Dependencies for full MNE-Python functionality (other than raw/epochs export)
-full = [
+# We first define a variant without any Qt bindings. The "complete" variant, mne[full],
+# makes an opinionated choice and installs PyQt6.
+# We also offter two more variants: mne[full-qt6] (which is equivalent to mne[full]),
+# and mne[full-pyside6], which will install PySide6 instead of PyQt6.
+full-no-qt = [
     "mne[hdf5]",
     "qtpy",
-    "PyQt6!=6.6.0",
-    "PyQt6-Qt6!=6.6.0,!=6.7.0",
     "pyobjc-framework-Cocoa>=5.2.0; platform_system=='Darwin'",
     "sip",
     "scikit-learn",
@@ -106,6 +108,10 @@ full = [
     "defusedxml",
     "neo",
 ]
+full = ["mne[full-no-qt]", "PyQt6!=6.6.0", "PyQt6-Qt6!=6.6.0,!=6.7.0"]
+full-pyqt6 = ["mne[full]"]
+full-pyside6 = ["mne[full-no-qt]", "PySide6"]
+
 
 # Dependencies for running the test infrastructure
 test = [