diff --git a/pylib/anki/importing/csvfile.py b/pylib/anki/importing/csvfile.py
index ee2c3e204..861651fdf 100644
--- a/pylib/anki/importing/csvfile.py
+++ b/pylib/anki/importing/csvfile.py
@@ -56,7 +56,7 @@ class TextImporter(NoteImporter):
             log.append(_("Aborted: %s") % str(e))
         self.log = log
         self.ignored = ignored
-        self.fileobj.close()
+        self.close()
         return notes
 
     def open(self) -> None:
@@ -134,6 +134,20 @@ class TextImporter(NoteImporter):
         self.open()
         return self.numFields
 
+    def close(self):
+        if self.fileobj:
+            self.fileobj.close()
+            self.fileobj = None
+
+    def __del__(self):
+        self.close()
+        try:
+            super().__del__  # type: ignore
+        except AttributeError:
+            pass
+        else:
+            super().__del__(self)  # type: ignore
+
     def noteFromFields(self, fields: List[str]) -> ForeignNote:
         note = ForeignNote()
         note.fields.extend([x for x in fields])
diff --git a/pylib/anki/importing/supermemo_xml.py b/pylib/anki/importing/supermemo_xml.py
index fb9461ae7..248a1fa10 100644
--- a/pylib/anki/importing/supermemo_xml.py
+++ b/pylib/anki/importing/supermemo_xml.py
@@ -300,7 +300,8 @@ class SupermemoXmlImporter(NoteImporter):
 
     # OPEN AND LOAD
     def openAnything(self, source):
-        "Open any source / actually only openig of files is used"
+        """Open any source / actually only opening of files is used
+        @return an open handle which must be closed after use, i.e., handle.close()"""
 
         if source == "-":
             return sys.stdin
diff --git a/pylib/anki/latex.py b/pylib/anki/latex.py
index 9aeac75e9..6202980c0 100644
--- a/pylib/anki/latex.py
+++ b/pylib/anki/latex.py
@@ -138,7 +138,8 @@ package in the LaTeX header instead."""
             if call(latexCmd, stdout=log, stderr=log):
                 return _errMsg(latexCmd[0], texpath)
         # add to media
-        data = open(png_or_svg, "rb").read()
+        with open(png_or_svg, "rb") as file:
+            data = file.read()
         col.media.write_data(extracted.filename, data)
         os.unlink(png_or_svg)
         return None
diff --git a/pylib/anki/sync.py b/pylib/anki/sync.py
index 60be194f1..3a597cdde 100644
--- a/pylib/anki/sync.py
+++ b/pylib/anki/sync.py
@@ -639,7 +639,8 @@ class FullSyncer(HttpSyncer):
         if cont == "upgradeRequired":
             hooks.sync_stage_did_change("upgradeRequired")
             return None
-        open(tpath, "wb").write(cont)
+        with open(tpath, "wb") as file:
+            file.write(cont)
         # check the received file is ok
         d = DB(tpath)
         assert d.scalar("pragma integrity_check") == "ok"
@@ -665,6 +666,7 @@ class FullSyncer(HttpSyncer):
             return False
         # apply some adjustments, then upload
         self.col.beforeUpload()
-        if self.req("upload", open(self.col.path, "rb")) != b"OK":
-            return False
+        with open(self.col.path, "rb") as file:
+            if self.req("upload", file) != b"OK":
+                return False
         return True
diff --git a/pylib/tests/test_exporting.py b/pylib/tests/test_exporting.py
index 83f6ca93e..f8903cf72 100644
--- a/pylib/tests/test_exporting.py
+++ b/pylib/tests/test_exporting.py
@@ -151,11 +151,13 @@ def test_export_textnote():
     os.close(fd)
     os.unlink(f)
     e.exportInto(f)
-    assert open(f).readline() == "foo\tbar<br>\ttag tag2\n"
+    with open(f) as file:
+        assert file.readline() == "foo\tbar<br>\ttag tag2\n"
     e.includeTags = False
     e.includeHTML = False
     e.exportInto(f)
-    assert open(f).readline() == "foo\tbar\n"
+    with open(f) as file:
+        assert file.readline() == "foo\tbar\n"
 
 
 def test_exporters():
diff --git a/pylib/tools/hookslib.py b/pylib/tools/hookslib.py
index c3539cf44..f06775507 100644
--- a/pylib/tools/hookslib.py
+++ b/pylib/tools/hookslib.py
@@ -154,11 +154,14 @@ def update_file(path: str, hooks: List[Hook]):
     for hook in hooks:
         code += hook.code()
 
-    orig = open(path).read()
+    with open(path) as file:
+        orig = file.read()
+
     new = re.sub(
         "(?s)# @@AUTOGEN@@.*?# @@AUTOGEN@@\n",
         f"# @@AUTOGEN@@\n\n{code}# @@AUTOGEN@@\n",
         orig,
     )
 
-    open(path, "wb").write(new.encode("utf8"))
+    with open(path, "wb") as file:
+        file.write(new.encode("utf8"))
diff --git a/qt/aqt/editor.py b/qt/aqt/editor.py
index 3948ef105..730cb356c 100644
--- a/qt/aqt/editor.py
+++ b/qt/aqt/editor.py
@@ -808,7 +808,8 @@ to a cloze type first, via Edit>Change Note Type."""
                 req = urllib.request.Request(
                     url, None, {"User-Agent": "Mozilla/5.0 (compatible; Anki)"}
                 )
-                filecontents = urllib.request.urlopen(req).read()
+                with urllib.request.urlopen(req) as response:
+                    filecontents = response.read()
             else:
                 reqs = HttpClient()
                 reqs.timeout = 30
@@ -1129,7 +1130,8 @@ class EditorWebView(AnkiWebView):
         if not os.path.exists(path):
             return
 
-        data = open(path, "rb").read()
+        with open(path, "rb") as file:
+            data = file.read()
         fname = self.editor._addPastedImage(data, ext)
         if fname:
             return self.editor.fnameToLink(fname)
diff --git a/qt/aqt/importing.py b/qt/aqt/importing.py
index 7c5204202..7c757cd48 100644
--- a/qt/aqt/importing.py
+++ b/qt/aqt/importing.py
@@ -505,7 +505,8 @@ def _replaceWithApkg(mw, filename, backup):
             if os.path.exists(dest) and size == os.stat(dest).st_size:
                 continue
             data = z.read(cStr)
-            open(dest, "wb").write(data)
+            with open(dest, "wb") as file:
+                file.write(data)
 
         z.close()
 
diff --git a/qt/aqt/main.py b/qt/aqt/main.py
index 124b0b9eb..0a70d3e5a 100644
--- a/qt/aqt/main.py
+++ b/qt/aqt/main.py
@@ -567,7 +567,8 @@ from the profile screen."
             self.data = data
             # create the file in calling thread to ensure the same
             # file is not created twice
-            open(self.path, "wb").close()
+            with open(self.path, "wb") as file:
+                pass
 
         def run(self):
             z = zipfile.ZipFile(self.path, "w", zipfile.ZIP_DEFLATED)
diff --git a/qt/aqt/profiles.py b/qt/aqt/profiles.py
index ea373102d..4bd22e631 100644
--- a/qt/aqt/profiles.py
+++ b/qt/aqt/profiles.py
@@ -467,11 +467,12 @@ create table if not exists profiles
         "Create a new profile if none exists."
         self.create(_("User 1"))
         p = os.path.join(self.base, "README.txt")
-        open(p, "w", encoding="utf8").write(
-            without_unicode_isolation(
-                tr(TR.PROFILES_FOLDER_README, link=appHelpSite + "#startupopts")
+        with open(p, "w", encoding="utf8") as file:
+            file.write(
+                without_unicode_isolation(
+                    tr(TR.PROFILES_FOLDER_README, link=appHelpSite + "#startupopts")
+                )
             )
-        )
 
     # Default language
     ######################################################################
@@ -544,7 +545,8 @@ create table if not exists profiles
         if not os.path.exists(path):
             return "software"
 
-        mode = open(path, "r").read().strip()
+        with open(path, "r") as file:
+            mode = file.read().strip()
 
         if mode == "angle" and isWin:
             return mode
@@ -553,7 +555,8 @@ create table if not exists profiles
         return "auto"
 
     def setGlMode(self, mode):
-        open(self._glPath(), "w").write(mode)
+        with open(self._glPath(), "w") as file:
+            file.write(mode)
 
     def nextGlMode(self):
         mode = self.glMode()
diff --git a/qt/aqt/webview.py b/qt/aqt/webview.py
index 1c5f78f6e..92819d64a 100644
--- a/qt/aqt/webview.py
+++ b/qt/aqt/webview.py
@@ -40,13 +40,16 @@ class AnkiWebPage(QWebEnginePage):  # type: ignore
         self._channel.registerObject("py", self._bridge)
         self.setWebChannel(self._channel)
 
-        js = QFile(":/qtwebchannel/qwebchannel.js")
-        assert js.open(QIODevice.ReadOnly)
-        js = bytes(js.readAll()).decode("utf-8")
+        qwebchannel = ":/qtwebchannel/qwebchannel.js"
+        jsfile = QFile(qwebchannel)
+        if not jsfile.open(QIODevice.ReadOnly):
+            print(f"Error opening '{qwebchannel}': {jsfile.error()}", file=sys.stderr)
+        jstext = bytes(jsfile.readAll()).decode("utf-8")
+        jsfile.close()
 
         script = QWebEngineScript()
         script.setSourceCode(
-            js
+            jstext
             + """
             var pycmd;
             new QWebChannel(qt.webChannelTransport, function(channel) {
diff --git a/qt/po/scripts/duplicate-string.py b/qt/po/scripts/duplicate-string.py
index ee0b681cf..a32e82cb8 100644
--- a/qt/po/scripts/duplicate-string.py
+++ b/qt/po/scripts/duplicate-string.py
@@ -38,7 +38,8 @@ def dupe_key(fname, old, new):
     if not os.path.exists(fname):
         return
 
-    orig = open(fname).read()
+    with open(fname) as file:
+        orig = file.read()
     obj = parse(orig)
     for ent in obj.body:
         if isinstance(ent, Junk):
@@ -68,7 +69,8 @@ def dupe_key(fname, old, new):
             raise Exception(f"introduced junk! {fname} {ent}")
 
     # it's ok, write it out
-    open(fname, "w").write(modified)
+    with open(fname, "w") as file:
+        file.write(modified)
 
 
 i18ndir = os.path.join(os.path.dirname(ftl_filename), "..")
diff --git a/qt/po/scripts/extract-po-string.py b/qt/po/scripts/extract-po-string.py
index b8bad1b3f..488c2d97a 100644
--- a/qt/po/scripts/extract-po-string.py
+++ b/qt/po/scripts/extract-po-string.py
@@ -107,7 +107,8 @@ def plural_text(key, lang, translation):
 def add_simple_message(fname, key, message):
     orig = ""
     if os.path.exists(fname):
-        orig = open(fname).read()
+        with open(fname) as file:
+            orig = file.read()
 
     obj = parse(orig)
     for ent in obj.body:
@@ -126,7 +127,8 @@ def add_simple_message(fname, key, message):
             raise Exception(f"introduced junk! {fname} {ent}")
 
     # it's ok, write it out
-    open(fname, "w").write(modified)
+    with open(fname, "w") as file:
+        file.write(modified)
 
 
 def add_message(fname, key, translation):
diff --git a/qt/po/scripts/extract-po-strings.py b/qt/po/scripts/extract-po-strings.py
index 699825cbd..40e779ba0 100644
--- a/qt/po/scripts/extract-po-strings.py
+++ b/qt/po/scripts/extract-po-strings.py
@@ -55,5 +55,6 @@ for lang in folders:
             continue
         langs.setdefault(lang, {})[entry.msgid] = msgstr
 
-open("strings.json", "w").write(json.dumps(langs))
+with open("strings.json", "w") as file:
+    file.write(json.dumps(langs))
 print("wrote to strings.json")