diff --git a/pylib/anki/_backend/__init__.py b/pylib/anki/_backend/__init__.py
index d486d9ab3..dc443c853 100644
--- a/pylib/anki/_backend/__init__.py
+++ b/pylib/anki/_backend/__init__.py
@@ -40,7 +40,8 @@ from .fluent import GeneratedTranslations, LegacyTranslationEnum
 # the following comment is required to suppress a warning that only shows up
 # when there are other pylint failures
 # pylint: disable=c-extension-no-member
-assert rsbridge.buildhash() == anki.buildinfo.buildhash
+if rsbridge.buildhash() != anki.buildinfo.buildhash:
+    raise Exception("rsbridge and anki build hashes do not match")
 
 
 class RustBackend(RustBackendGenerated):
diff --git a/pylib/anki/cards.py b/pylib/anki/cards.py
index f79f94d76..aa5225f7d 100644
--- a/pylib/anki/cards.py
+++ b/pylib/anki/cards.py
@@ -201,7 +201,8 @@ class Card(DeprecatedNamesMixin):
 
     def set_user_flag(self, flag: int) -> None:
         print("use col.set_user_flag_for_cards() instead")
-        assert 0 <= flag <= 7
+        if not 0 <= flag <= 7:
+            raise Exception("invalid flag")
         self.flags = (self.flags & ~0b111) | flag
 
     @deprecated(info="use card.render_output() directly")
diff --git a/pylib/anki/collection.py b/pylib/anki/collection.py
index 8d38229d5..7a9f31096 100644
--- a/pylib/anki/collection.py
+++ b/pylib/anki/collection.py
@@ -264,8 +264,8 @@ class Collection(DeprecatedNamesMixin):
         self.models._clear_cache()
 
     def reopen(self, after_full_sync: bool = False) -> None:
-        assert not self.db
-        assert self.path.endswith(".anki2")
+        if self.db:
+            raise Exception("reopen() called with open db")
 
         self._last_checkpoint_at = time.time()
         self._undo: _UndoInfo = None
diff --git a/pylib/anki/decks.py b/pylib/anki/decks.py
index cf7e08c8a..1baabbe71 100644
--- a/pylib/anki/decks.py
+++ b/pylib/anki/decks.py
@@ -109,7 +109,8 @@ class DeckManager(DeprecatedNamesMixin):
 
     def add_deck_legacy(self, deck: DeckDict) -> OpChangesWithId:
         "Add a deck created with new_deck_legacy(). Must have id of 0."
-        assert deck["id"] == 0
+        if not deck["id"] == 0:
+            raise Exception("id should be 0")
         return self.col._backend.add_deck_legacy(to_json_bytes(deck))
 
     def id(
diff --git a/pylib/anki/importing/noteimp.py b/pylib/anki/importing/noteimp.py
index 7792de96e..3c57318e3 100644
--- a/pylib/anki/importing/noteimp.py
+++ b/pylib/anki/importing/noteimp.py
@@ -117,7 +117,8 @@ class NoteImporter(Importer):
 
     def importNotes(self, notes: list[ForeignNote]) -> None:
         "Convert each card into a note, apply attributes and add to col."
-        assert self.mappingOk()
+        if not self.mappingOk():
+            raise Exception("mapping not ok")
         # note whether tags are mapped
         self._tagsMapped = False
         for f in self.mapping:
diff --git a/pylib/anki/models.py b/pylib/anki/models.py
index 71c2c75af..96ca68888 100644
--- a/pylib/anki/models.py
+++ b/pylib/anki/models.py
@@ -304,12 +304,14 @@ class ModelManager(DeprecatedNamesMixin):
     def rename_field(
         self, notetype: NotetypeDict, field: FieldDict, new_name: str
     ) -> None:
-        assert field in notetype["flds"]
+        if not field in notetype["flds"]:
+            raise Exception("invalid field")
         field["name"] = new_name
 
     def set_sort_index(self, notetype: NotetypeDict, idx: int) -> None:
         "Modifies schema."
-        assert 0 <= idx < len(notetype["flds"])
+        if not 0 <= idx < len(notetype["flds"]):
+            raise Exception("invalid sort index")
         notetype["sortf"] = idx
 
     # Adding & changing templates
@@ -332,7 +334,8 @@ class ModelManager(DeprecatedNamesMixin):
 
     def remove_template(self, notetype: NotetypeDict, template: TemplateDict) -> None:
         "Modifies schema."
-        assert len(notetype["tmpls"]) > 1
+        if not len(notetype["tmpls"]) > 1:
+            raise Exception("must have 1 template")
         notetype["tmpls"].remove(template)
 
     def reposition_template(
diff --git a/pylib/anki/notes.py b/pylib/anki/notes.py
index b78106475..caffedcae 100644
--- a/pylib/anki/notes.py
+++ b/pylib/anki/notes.py
@@ -34,7 +34,8 @@ class Note(DeprecatedNamesMixin):
         model: NotetypeDict | NotetypeId | None = None,
         id: NoteId | None = None,
     ) -> None:
-        assert not (model and id)
+        if model and id:
+            raise Exception("only model or id should be provided")
         notetype_id = model["id"] if isinstance(model, dict) else model
         self.col = col.weakref()
 
@@ -76,7 +77,8 @@ class Note(DeprecatedNamesMixin):
     def flush(self) -> None:
         """This preserves any current checkpoint.
         For an undo entry, use col.update_note() instead."""
-        assert self.id != 0
+        if self.id == 0:
+            raise Exception("can't flush a new note")
         self.col._backend.update_notes(
             notes=[self._to_backend_note()], skip_undo_entry=True
         )
diff --git a/pylib/anki/scheduler/v2.py b/pylib/anki/scheduler/v2.py
index aa330c5ab..924f235c9 100644
--- a/pylib/anki/scheduler/v2.py
+++ b/pylib/anki/scheduler/v2.py
@@ -449,8 +449,8 @@ limit ?"""
     ##########################################################################
 
     def answerCard(self, card: Card, ease: int) -> None:
-        assert 1 <= ease <= 4
-        assert 0 <= card.queue <= 4
+        if (not 1 <= ease <= 4) or (not 0 <= card.queue <= 4):
+            raise Exception("invalid ease or queue")
         self.col.save_card_review_undo_info(card)
         if self._burySiblingsOnAnswer:
             self._burySiblings(card)
@@ -772,7 +772,8 @@ limit ?"""
     # note: when adding revlog entries in the future, make sure undo
     # code deletes the entries
     def _answerCardPreview(self, card: Card, ease: int) -> None:
-        assert 1 <= ease <= 2
+        if not 1 <= ease <= 2:
+            raise Exception("invalid ease")
 
         if ease == BUTTON_ONE:
             # repeat after delay
@@ -799,7 +800,8 @@ limit ?"""
             card.odid = DeckId(0)
 
     def _restorePreviewCard(self, card: Card) -> None:
-        assert card.odid
+        if not card.odid:
+            raise Exception("card should have odid set")
 
         card.due = card.odue
 
@@ -965,9 +967,12 @@ limit ?"""
 
     # next interval for card when answered early+correctly
     def _earlyReviewIvl(self, card: Card, ease: int) -> int:
-        assert card.odid and card.type == CARD_TYPE_REV
-        assert card.factor
-        assert ease > 1
+        if (
+            not (card.odid and card.type == CARD_TYPE_REV)
+            or not card.factor
+            or not ease > 1
+        ):
+            raise Exception("invalid input to earlyReviewIvl")
 
         elapsed = card.ivl - (card.odue - self.today)
 
diff --git a/pylib/anki/scheduler/v3.py b/pylib/anki/scheduler/v3.py
index a77704c8d..0c959f968 100644
--- a/pylib/anki/scheduler/v3.py
+++ b/pylib/anki/scheduler/v3.py
@@ -72,7 +72,7 @@ class Scheduler(SchedulerBaseWithLegacy):
         elif rating == CardAnswer.EASY:
             new_state = states.easy
         else:
-            assert False, "invalid rating"
+            raise Exception("invalid rating")
 
         return CardAnswer(
             card_id=card.id,
@@ -157,7 +157,7 @@ class Scheduler(SchedulerBaseWithLegacy):
         elif ease == BUTTON_FOUR:
             rating = CardAnswer.EASY
         else:
-            assert False, "invalid ease"
+            raise Exception("invalid ease")
 
         states = self.col._backend.get_next_card_states(card.id)
         changes = self.answer_card(
@@ -223,7 +223,7 @@ class Scheduler(SchedulerBaseWithLegacy):
         elif ease == BUTTON_FOUR:
             new_state = states.easy
         else:
-            assert False, "invalid ease"
+            raise Exception("invalid ease")
 
         return self._interval_for_state(new_state)
 
diff --git a/qt/aqt/deckconf.py b/qt/aqt/deckconf.py
index b4bba4e6a..5388c214e 100644
--- a/qt/aqt/deckconf.py
+++ b/qt/aqt/deckconf.py
@@ -267,7 +267,8 @@ class DeckConf(QDialog):
                 continue
             try:
                 i = float(item)
-                assert i > 0
+                if not i > 0:
+                    raise Exception("0 invalid")
                 if i == int(i):
                     i = int(i)
                 ret.append(i)
diff --git a/qt/aqt/filtered_deck.py b/qt/aqt/filtered_deck.py
index e225cb0e7..098756348 100644
--- a/qt/aqt/filtered_deck.py
+++ b/qt/aqt/filtered_deck.py
@@ -333,7 +333,8 @@ class FilteredDeckConfigDialog(QDialog):
                 continue
             try:
                 i = float(item)
-                assert i > 0
+                if not i > 0:
+                    raise Exception("0 invalid")
                 ret.append(i)
             except:
                 # invalid, don't update
diff --git a/qt/aqt/main.py b/qt/aqt/main.py
index f1c50e321..63fc3f131 100644
--- a/qt/aqt/main.py
+++ b/qt/aqt/main.py
@@ -608,7 +608,8 @@ class AnkiQt(QMainWindow):
 
     def backup(self) -> None:
         "Read data into memory, and complete backup on a background thread."
-        assert not self.col or not self.col.db
+        if self.col and self.col.db:
+            raise Exception("collection must be closed")
 
         nbacks = self.pm.profile["numBackups"]
         if not nbacks or dev_mode:
@@ -706,7 +707,8 @@ class AnkiQt(QMainWindow):
         self._background_op_count -= 1
         if not self._background_op_count:
             gui_hooks.backend_did_block()
-        assert self._background_op_count >= 0
+        if not self._background_op_count >= 0:
+            raise Exception("no background ops active")
 
     def _synthesize_op_did_execute_from_reset(self) -> None:
         """Fire the `operation_did_execute` hook with everything marked as changed,
@@ -1357,7 +1359,8 @@ title="{}" {}>{}</button>""".format(
 
     # this will gradually be phased out
     def onSchemaMod(self, arg: bool) -> bool:
-        assert self.inMainThread()
+        if not self.inMainThread():
+            raise Exception("not in main thread")
         progress_shown = self.progress.busy()
         if progress_shown:
             self.progress.finish()
diff --git a/qt/aqt/profiles.py b/qt/aqt/profiles.py
index 5e596d8bf..07c86ec6e 100644
--- a/qt/aqt/profiles.py
+++ b/qt/aqt/profiles.py
@@ -199,7 +199,8 @@ class ProfileManager:
         return pickle.dumps(obj, protocol=4)
 
     def load(self, name: str) -> bool:
-        assert name != "_global"
+        if name == "_global":
+            raise Exception("_global is not a valid name")
         data = self.db.scalar(
             "select cast(data as blob) from profiles where name = ?", name
         )
@@ -381,7 +382,8 @@ class ProfileManager:
         # open DB file and read data
         try:
             self.db = DB(path)
-            assert self.db.scalar("pragma integrity_check") == "ok"
+            if not self.db.scalar("pragma integrity_check") == "ok":
+                raise Exception("corrupt db")
             self.db.execute(
                 """
 create table if not exists profiles
diff --git a/qt/aqt/sync.py b/qt/aqt/sync.py
index 3dcd3a9c2..7e8eb83ed 100644
--- a/qt/aqt/sync.py
+++ b/qt/aqt/sync.py
@@ -88,7 +88,8 @@ def on_normal_sync_timer(mw: aqt.main.AnkiQt) -> None:
 
 def sync_collection(mw: aqt.main.AnkiQt, on_done: Callable[[], None]) -> None:
     auth = mw.pm.sync_auth()
-    assert auth
+    if not auth:
+        raise Exception("expected auth")
 
     def on_timer() -> None:
         on_normal_sync_timer(mw)
diff --git a/qt/aqt/utils.py b/qt/aqt/utils.py
index 01cef2160..0d43b2065 100644
--- a/qt/aqt/utils.py
+++ b/qt/aqt/utils.py
@@ -431,7 +431,8 @@ def getFile(
     multi: bool = False,  # controls whether a single or multiple files is returned
 ) -> Sequence[str] | str | None:
     "Ask the user for a file."
-    assert not dir or not key
+    if dir and key:
+        raise Exception("expected dir or key")
     if not dir:
         dirkey = f"{key}Directory"
         dir = aqt.mw.pm.profile.get(dirkey, "")