Enable strict type checking

.github/workflows/test.yaml

@@ -270,7 +270,7 @@ jobs:
           environments: ${{ matrix.environment }}
       - name: Test Type
         run: |
-          pixi run -e ${{ matrix.environment }} test-type || echo "Failed"
+          pixi run -e ${{ matrix.environment }} test-type
 
   result_test_suite:
     name: result:test

doc/generate_modules.py

@@ -57,7 +57,7 @@ def write_file(name, text, opts):
     """Write the output file for module/package <name>."""
     if opts.dryrun:
         return
-    fname = os.path.join(opts.destdir, "%s.%s" % (name, opts.suffix))
+    fname = os.path.join(opts.destdir, "{}.{}".format(name, opts.suffix))
     if not opts.force and os.path.isfile(fname):
         print('File %s already exists, skipping.' % fname)
     else:
@@ -69,7 +69,7 @@ def write_file(name, text, opts):
 def format_heading(level, text):
     """Create a heading of <level> [1, 2 or 3 supported]."""
     underlining = ['=', '-', '~', ][level-1] * len(text)
-    return '%s\n%s\n\n' % (text, underlining)
+    return '{}\n{}\n\n'.format(text, underlining)
 
 def format_directive(module, package=None):
     """Create the automodule directive and add the options."""
@@ -89,7 +89,7 @@ def create_module_file(package, module, opts):
 def create_package_file(root, master_package, subroot, py_files, opts, subs):
     """Build the text of the file and write the file."""
     package = os.path.split(root)[-1]
-    text = format_heading(1, '%s.%s Package' % (master_package, package))
+    text = format_heading(1, '{}.{} Package'.format(master_package, package))
     text += '\n---------\n\n'
     # add each package's module
     for py_file in py_files:
@@ -114,7 +114,7 @@ def create_package_file(root, master_package, subroot, py_files, opts, subs):
         text += format_heading(2, 'Subpackages')
         text += '.. toctree::\n\n'
         for sub in subs:
-            text += '    %s.%s\n' % (makename(master_package, subroot), sub)
+            text += '    {}.{}\n'.format(makename(master_package, subroot), sub)
         text += '\n'
 
     write_file(makename(master_package, subroot), text, opts)

examples/apps/django/sliders/sinewave.py

@@ -16,7 +16,7 @@ class SineWave(param.Parameterized):
     y_range = param.Range(default=(-2.5,2.5),bounds=(-10,10))
 
     def __init__(self, **params):
-        super(SineWave, self).__init__(**params)
+        super().__init__(**params)
         x, y = self.sine()
         self.cds = ColumnDataSource(data=dict(x=x, y=y))
         self.plot = figure(height=400, width=400,

examples/apps/django_multi_apps/gbm/pn_model.py

@@ -17,7 +17,7 @@ class GBM(param.Parameterized):
     refresh = pn.widgets.Button(name="Refresh", button_type='primary')
 
     def __init__(self, **params):
-        super(GBM, self).__init__(**params)
+        super().__init__(**params)
 
     # update the plot for every changes
     # @param.depends('mean', 'volatility', 'maturity', 'n_observations', 'n_simulations', watch=True)

examples/apps/django_multi_apps/sliders/pn_model.py

@@ -15,7 +15,7 @@ class SineWave(param.Parameterized):
     y_range = param.Range(default=(-2.5, 2.5), bounds=(-10, 10))
 
     def __init__(self, **params):
-        super(SineWave, self).__init__(**params)
+        super().__init__(**params)
         x, y = self.sine()
         self.cds = ColumnDataSource(data=dict(x=x, y=y))
         self.plot = figure(height=400, width=400,

examples/apps/django_multi_apps/stockscreener/pn_model.py

@@ -19,7 +19,7 @@ class StockScreener(param.Parameterized):
     def __init__(self, df, **params):
         start = dt.date(year=df.index[0].year, month=df.index[0].month, day=df.index[0].day)
         end = dt.date(year=df.index[-1].year, month=df.index[-1].month, day=df.index[-1].day)
-        super(StockScreener, self).__init__(df=df, start=start, **params)
+        super().__init__(df=df, start=start, **params)
         self.param.start.bounds = (start, end)
         columns = list(self.df.columns)
         self.param.index.objects = columns

examples/apps/django_multi_apps/stockscreener/pn_model_20122019.py

@@ -41,7 +41,7 @@ class StockScreener(param.Parameterized):
     From = pn.widgets.DateSlider()
 
     def __init__(self, df, **params):
-        super(StockScreener, self).__init__(**params)
+        super().__init__(**params)
         # init df
         self.df = df
         self.start_date = dt.datetime(year=df.index[0].year, month=df.index[0].month, day=df.index[0].day)

examples/apps/fastApi/sliders/sinewave.py

@@ -15,7 +15,7 @@ class SineWave(param.Parameterized):
     y_range = param.Range(default=(-2.5, 2.5), bounds=(-10, 10))
 
     def __init__(self, **params):
-        super(SineWave, self).__init__(**params)
+        super().__init__(**params)
         x, y = self.sine()
         self.cds = ColumnDataSource(data=dict(x=x, y=y))
         self.plot = figure(height=400, width=400,

examples/apps/fastApi_multi_apps/sliders/sinewave.py

@@ -15,7 +15,7 @@ class SineWave(param.Parameterized):
     y_range = param.Range(default=(-2.5, 2.5), bounds=(-10, 10))
 
     def __init__(self, **params):
-        super(SineWave, self).__init__(**params)
+        super().__init__(**params)
         x, y = self.sine()
         self.cds = ColumnDataSource(data=dict(x=x, y=y))
         self.plot = figure(height=400, width=400,

examples/apps/fastApi_multi_apps/sliders2/sinewave.py

@@ -15,7 +15,7 @@ class SineWave(param.Parameterized):
     y_range = param.Range(default=(-2.5, 2.5), bounds=(-10, 10))
 
     def __init__(self, **params):
-        super(SineWave, self).__init__(**params)
+        super().__init__(**params)
         x, y = self.sine()
         self.cds = ColumnDataSource(data=dict(x=x, y=y))
         self.plot = figure(height=400, width=400,

panel/__main__.py

@@ -1,7 +1,7 @@
 import sys
 
 
-def main():
+def main() -> None:
     from panel.command import main as _main
 
    # Main entry point (see setup.py)

panel/_param.py

@@ -1,5 +1,18 @@
+from __future__ import annotations
+
+from typing import (
+    TYPE_CHECKING, Any, Literal, TypeAlias, cast,
+)
+
+from bokeh.core.enums import enumeration
 from param import Parameter, _is_number
 
+if TYPE_CHECKING:
+    MarginType: TypeAlias = int | tuple[int, int] | tuple[int, int, int] | tuple[int, int, int, int]
+
+AlignmentType = Literal["auto", "start", "center", "end"]
+Alignment = enumeration(AlignmentType)
+
 
 class Align(Parameter):
     """
@@ -8,16 +21,20 @@ class Align(Parameter):
     to the (vertical, horizontal) alignment.
     """
 
-    def __init__(self, default='start', **params):
+    def __init__(
+        self,
+        default: AlignmentType | tuple[AlignmentType, AlignmentType] = "start",
+        **params: Any
+    ):
         super().__init__(default=default, **params)
         self._validate(default)
 
-    def _validate(self, val):
+    def _validate(self, val: Any) -> None:
         self._validate_value(val, self.allow_None)
 
-    def _validate_value(self, val, allow_None, valid=('auto', 'start', 'center', 'end')):
-        if ((val is None and allow_None) or val in valid or
-            (isinstance(val, tuple) and len(val) == 2 and all(v in valid for v in val))):
+    def _validate_value(self, val: Any, allow_None: bool) -> None:
+        if ((val is None and allow_None) or val in Alignment or
+            (isinstance(val, tuple) and len(val) == 2 and all(v in Alignment for v in val))):
             return
         raise ValueError(
             f"Align parameter {self.name!r} must be one of 'start', "
@@ -36,10 +53,10 @@ def __init__(self, default=None, allow_None=True, **params):
         super().__init__(default=default, allow_None=allow_None, **params)
         self._validate(default)
 
-    def _validate(self, val):
+    def _validate(self, val: Any) -> None:
         self._validate_value(val, self.allow_None)
 
-    def _validate_value(self, val, allow_None):
+    def _validate_value(self, val: Any, allow_None: bool) -> None:
         if (val is None and allow_None) or val == 'auto' or _is_number(val):
             return
         raise ValueError(
@@ -60,7 +77,7 @@ def __init__(self, default=None, allow_None=True, **params):
         super().__init__(default=default, allow_None=allow_None, **params)
         self._validate(default)
 
-    def _validate_value(self, val, allow_None):
+    def _validate_value(self, val: Any, allow_None: bool) -> None:
         if val is None and allow_None:
             return
         if not isinstance(val, (tuple, int)):
@@ -69,27 +86,32 @@ def _validate_value(self, val, allow_None):
                 f'tuple values, not values of not {type(val)!r}.'
             )
 
-    def _validate_length(self, val):
-        if not isinstance(val, tuple) or len(val) in (2, 4):
+    def _validate_length(self, val: Any) -> None:
+        if not isinstance(val, tuple) or (1 < len(val) < 5):
             return
         raise ValueError(
             f'Margin parameter {self.name!r} only takes integer and '
             f'tuple values of length 2 (vertical, horizontal) or 4 '
             '(top, right, bottom, left).'
         )
 
-    def _validate(self, val):
+    def _validate(self, val: Any) -> None:
         self._validate_value(val, self.allow_None)
         self._validate_length(val)
 
     @classmethod
-    def serialize(cls, value):
+    def serialize(cls, value: MarginType) -> Literal['null'] | list[int] | int:
         if value is None:
             return 'null'
         return list(value) if isinstance(value, tuple) else value
 
     @classmethod
-    def deserialize(cls, value):
+    def deserialize(cls, value: Literal['null'] | list[int] | int) -> MarginType | None:
         if value == 'null':
             return None
-        return tuple(value) if isinstance(value, list) else value
+        elif isinstance(value, list):
+            n = len(value)
+            if (n < 2 or n > 5):
+                raise ValueError(f'Cannot deserialize list of length {n}.')
+            return cast(MarginType, tuple(value))
+        return value

panel/auth.py

@@ -12,6 +12,7 @@
 
 from base64 import urlsafe_b64encode
 from functools import partial
+from typing import ClassVar
 
 import tornado
 
@@ -101,13 +102,13 @@ class OAuthLoginHandler(tornado.web.RequestHandler, OAuth2Mixin):
         'grant_type':    'authorization_code'
     }
 
-    _access_token_header = None
+    _access_token_header: ClassVar[str | None] = None
 
-    _state_cookie = None
+    _state_cookie: ClassVar[str | None] = None
 
     _error_template = ERROR_TEMPLATE
 
-    _login_endpoint = '/login'
+    _login_endpoint: ClassVar[str] = '/login'
 
     @property
     def _SCOPE(self):

panel/chat/feed.py

@@ -8,14 +8,15 @@
 import asyncio
 import traceback
 
+from collections.abc import Callable
 from enum import Enum
 from inspect import (
     getfullargspec, isasyncgen, isasyncgenfunction, isawaitable,
     iscoroutinefunction, isgenerator, isgeneratorfunction, ismethod,
 )
 from io import BytesIO
 from typing import (
-    TYPE_CHECKING, Any, Callable, ClassVar, Literal,
+    TYPE_CHECKING, Any, ClassVar, Literal,
 )
 
 import param
@@ -409,7 +410,7 @@ def _upsert_message(
         is_stopped = self._callback_future is not None and self._callback_future.cancelled()
         if value is None:
             # don't add new message if the callback returns None
-            return
+            return None
         elif is_stopping or is_stopped:
             raise StopCallback("Callback was stopped.")
 
@@ -491,12 +492,14 @@ async def _serialize_response(self, response: Any) -> ChatMessage | None:
                 self._callback_state = CallbackState.GENERATING
                 async for token in response:
                     response_message = self._upsert_message(token, response_message)
-                    response_message.show_activity_dot = self.show_activity_dot
+                    if response_message is not None:
+                        response_message.show_activity_dot = self.show_activity_dot
             elif isgenerator(response):
                 self._callback_state = CallbackState.GENERATING
                 for token in response:
                     response_message = self._upsert_message(token, response_message)
-                    response_message.show_activity_dot = self.show_activity_dot
+                    if response_message is not None:
+                        response_message.show_activity_dot = self.show_activity_dot
             elif isawaitable(response):
                 response_message = self._upsert_message(await response, response_message)
             else:
@@ -527,7 +530,7 @@ async def _schedule_placeholder(
                 return
             await asyncio.sleep(0.1)
 
-    async def _handle_callback(self, message, loop: asyncio.BaseEventLoop):
+    async def _handle_callback(self, message, loop: asyncio.AbstractEventLoop):
         callback_args, callback_kwargs = self._gather_callback_args(message)
         if iscoroutinefunction(self.callback):
             response = await self.callback(*callback_args, **callback_kwargs)
@@ -561,16 +564,16 @@ async def _prepare_response(self, *_) -> None:
 
             num_entries = len(self._chat_log)
             loop = asyncio.get_event_loop()
-            future = loop.create_task(self._handle_callback(message, loop))
-            self._callback_future = future
+            task = loop.create_task(self._handle_callback(message, loop))
+            self._callback_future = task
             await asyncio.gather(
-                self._schedule_placeholder(future, num_entries), future,
+                self._schedule_placeholder(task, num_entries), task,
             )
         except StopCallback:
             # callback was stopped by user
             self._callback_state = CallbackState.STOPPED
         except Exception as e:
-            send_kwargs = dict(user="Exception", respond=False)
+            send_kwargs: dict[str, Any] = dict(user="Exception", respond=False)
             if self.callback_exception == "summary":
                 self.send(
                     f"Encountered `{e!r}`. "
@@ -633,7 +636,7 @@ def send(
                     "Cannot set user or avatar when explicitly sending "
                     "a ChatMessage. Set them directly on the ChatMessage."
                 )
-            message = value
+            message: ChatMessage | None = value
         else:
             if not isinstance(value, dict):
                 value = {"object": value}
@@ -690,7 +693,7 @@ def stream(
                 "a ChatMessage. Set them directly on the ChatMessage."
             )
         elif message:
-            if isinstance(value, (str, dict)):
+            if isinstance(value, str):
                 message.stream(value, replace=replace)
                 if user:
                     message.user = user
@@ -865,7 +868,7 @@ async def _prepare_prompt(*_) -> None:
                 send_kwargs["user"] = "Input"
             self.send(form, respond=False, **send_kwargs)
 
-            for _ in range(timeout * 10):  # sleeping for 0.1 seconds
+            for __ in range(timeout * 10):  # sleeping for 0.1 seconds
                 is_fulfilled = predicate(component) if predicate else True
                 submit_button.disabled = not is_fulfilled
                 if submit_button.clicks > 0:
@@ -958,7 +961,7 @@ def _serialize_for_transformers(
         self,
         messages: list[ChatMessage],
         role_names: dict[str, str | list[str]] | None = None,
-        default_role: str | None = "assistant",
+        default_role: str = "assistant",
         custom_serializer: Callable | None = None,
         **serialize_kwargs
     ) -> list[dict[str, Any]]:

panel/chat/input.py

@@ -1,8 +1,7 @@
 from __future__ import annotations
 
-from typing import (
-    TYPE_CHECKING, Any, ClassVar, Mapping, Optional,
-)
+from collections.abc import Mapping
+from typing import TYPE_CHECKING, Any, ClassVar
 
 import param
 
@@ -79,17 +78,17 @@ class ChatAreaInput(_PnTextAreaInput):
         **_PnTextAreaInput._rename,
     }
 
-    def _get_properties(self, doc: Document) -> dict[str, Any]:
+    def _get_properties(self, doc: Document | None = None) -> dict[str, Any]:
         props = super()._get_properties(doc)
         props.update({"value_input": self.value, "value": self.value})
         return props
 
     def _get_model(
         self,
         doc: Document,
-        root: Optional[Model] = None,
-        parent: Optional[Model] = None,
-        comm: Optional[Comm] = None,
+        root: Model | None = None,
+        parent: Model | None = None,
+        comm: Comm | None = None,
     ) -> Model:
         model = super()._get_model(doc, root, parent, comm)
         self._register_events("chat_message_event", model=model, doc=doc, comm=comm)