Make callable check more fine, doc, add noqa

mne/epochs.py

@@ -839,48 +839,38 @@ def _reject_setup(self, reject, flat):
             "previous ones"
         )
 
-        # Skip this check if old_reject, reject, old_flat, and flat are
-        # callables
-        is_callable = False
-        for rej in (reject, flat, old_reject, old_flat):
-            for key, val in rej.items():
-                if callable(val):
-                    is_callable = True
-
         # copy thresholds for channel types that were used previously, but not
         # passed this time
         for key in set(old_reject) - set(reject):
             reject[key] = old_reject[key]
-
-        if not is_callable:
-            # make sure new thresholds are at least as stringent
-            # as the old ones
-            for key in reject:
-                if key in old_reject and reject[key] > old_reject[key]:
-                    raise ValueError(
-                        bad_msg.format(
-                            kind="reject",
-                            key=key,
-                            new=reject[key],
-                            old=old_reject[key],
-                            op=">",
-                        )
+        # make sure new thresholds are at least as stringent as the old ones
+        for key in reject:
+            # Skip this check if old_reject and reject are callables
+            if callable(reject[key]):
+                continue
+            if key in old_reject and reject[key] > old_reject[key]:
+                raise ValueError(
+                    bad_msg.format(
+                        kind="reject",
+                        key=key,
+                        new=reject[key],
+                        old=old_reject[key],
+                        op=">",
                     )
+                )
 
-            # same for flat thresholds
-            for key in set(old_flat) - set(flat):
-                flat[key] = old_flat[key]
-            for key in flat:
-                if key in old_flat and flat[key] < old_flat[key]:
-                    raise ValueError(
-                        bad_msg.format(
-                            kind="flat",
-                            key=key,
-                            new=flat[key],
-                            old=old_flat[key],
-                            op="<",
-                        )
+        # same for flat thresholds
+        for key in set(old_flat) - set(flat):
+            flat[key] = old_flat[key]
+        for key in flat:
+            if callable(flat[key]):
+                continue
+            if key in old_flat and flat[key] < old_flat[key]:
+                raise ValueError(
+                    bad_msg.format(
+                        kind="flat", key=key, new=flat[key], old=old_flat[key], op="<"
                     )
+                )
 
         # after validation, set parameters
         self._bad_dropped = False
@@ -1544,7 +1534,7 @@ def drop(self, indices, reason="USER", verbose=None):
             Set epochs to remove by specifying indices to remove or a boolean
             mask to apply (where True values get removed). Events are
             correspondingly modified.
-        reason : str
+        reason : list | tuple | str
             Reason for dropping the epochs ('ECG', 'timeout', 'blink' etc).
             Default: 'USER'.
         %(verbose)s
@@ -3180,6 +3170,10 @@ class Epochs(BaseEpochs):
             See :meth:`~mne.Epochs.equalize_event_counts`
         - 'USER'
             For user-defined reasons (see :meth:`~mne.Epochs.drop`).
+
+        When dropping based on flat or reject parameters the tuple of
+        reasons contains a tuple of channels that satisfied the rejection
+        criteria.
     filename : str
         The filename of the object.
     times :  ndarray

mne/utils/docs.py

@@ -3828,7 +3828,7 @@ def _reflow_param_docstring(docstring, has_first_line=True, width=75):
 
     .. note:: If ``reject`` is a callable, than **any** criteria can be
             used to reject epochs (including maxima and minima).
-"""
+"""  # noqa: E501
 
 docdict[
     "reject_drop_bad"