ENH: check for dropping all channels

doc/changes/devel/12763.bugfix.rst

@@ -0,0 +1 @@
+Fix check for dropping all channels in :meth:`mne.io.Raw.drop_channels` and related methods, by :newcontrib:`Farzin Negahbani`.

doc/changes/names.inc

@@ -168,6 +168,8 @@
 
 .. _Fahimeh Mamashli: https://github.com/fmamashli
 
+.. _Farzin Negahbani: https://github.com/Farzin-Negahbani
+
 .. _Federico Raimondo: https://github.com/fraimondo
 
 .. _Federico Zamberlan: https://github.com/fzamberlan
@@ -508,6 +510,8 @@
 
 .. _Rotem Falach: https://github.com/Falach
 
+.. _Sammi Chekroud: https://github.com/schekroud
+
 .. _Samu Taulu: https://phys.washington.edu/people/samu-taulu
 
 .. _Samuel Deslauriers-Gauthier: https://github.com/sdeslauriers
@@ -536,6 +540,8 @@
 
 .. _Senwen Deng: https://snwn.de
 
+.. _Seyed Yahya Shirazi: https://neuromechanist.github.io
+
 .. _Sheraz Khan: https://github.com/SherazKhan
 
 .. _Silvia Cotroneo: https://github.com/sfc-neuro
@@ -625,7 +631,3 @@
 .. _Zhi Zhang: https://github.com/tczhangzhi/
 
 .. _Zvi Baratz: https://github.com/ZviBaratz
-
-.. _Seyed Yahya Shirazi: https://neuromechanist.github.io
-
-.. _Sammi Chekroud: https://github.com/schekroud

mne/channels/channels.py

@@ -602,6 +602,8 @@ def drop_channels(self, ch_names, on_missing="raise"):
 
         bad_idx = [self.ch_names.index(ch) for ch in ch_names if ch in self.ch_names]
         idx = np.setdiff1d(np.arange(len(self.ch_names)), bad_idx)
+        if len(idx) == 0:
+            raise ValueError("All channels would be dropped.")
         return self._pick_drop_channels(idx)
 
     @verbose

mne/channels/tests/test_channels.py

@@ -539,6 +539,8 @@ def test_drop_channels():
         raw.drop_channels(m_chs, on_missing="warn")
     # ...or ignored altogether
     raw.drop_channels(m_chs, on_missing="ignore")
+    with pytest.raises(ValueError, match="All channels"):
+        raw.drop_channels(raw.ch_names)
 
 
 def test_pick_channels():