diff --git a/CHANGES b/CHANGES
index d123080e4..139401e22 100644
--- a/CHANGES
+++ b/CHANGES
@@ -16,6 +16,14 @@ $ pip install --user --upgrade --pre libtmux
 
 _Maintenance only, no bug fixes, or new features_
 
+### Development
+
+- Code quality improved via [ruff] rules (#488)
+
+  This includes fixes made by hand, and with ruff's automated fixes. Despite
+  selecting additional rules, which include import sorting, ruff runs nearly
+  instantaneously when checking the whole codebase.
+
 ## libtmux 0.22.2 (2023-08-20)
 
 ### Development
diff --git a/conftest.py b/conftest.py
index d45b5ee5b..299041497 100644
--- a/conftest.py
+++ b/conftest.py
@@ -12,7 +12,6 @@
 import typing as t
 
 import pytest
-
 from _pytest.doctest import DoctestItem
 
 from libtmux.pytest_plugin import USING_ZSH
diff --git a/docs/conf.py b/docs/conf.py
index 522cdcbc5..a69842357 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -1,13 +1,12 @@
 # flake8: NOQA: E501
 import contextlib
 import inspect
-import sys
-from os.path import relpath
 import pathlib
+import sys
 import typing as t
+from os.path import relpath
 
-import libtmux  # NOQA
-from libtmux import test  # NOQA
+import libtmux
 
 if t.TYPE_CHECKING:
     from sphinx.application import Sphinx
@@ -166,9 +165,7 @@
 }
 
 
-def linkcode_resolve(
-    domain: str, info: t.Dict[str, str]
-) -> t.Union[None, str]:  # NOQA: C901
+def linkcode_resolve(domain: str, info: t.Dict[str, str]) -> t.Union[None, str]:
     """
     Determine the URL corresponding to Python object
 
@@ -191,7 +188,7 @@ def linkcode_resolve(
     for part in fullname.split("."):
         try:
             obj = getattr(obj, part)
-        except Exception:
+        except Exception:  # noqa: PERF203
             return None
 
     # strip decorators, which would resolve to the source of the decorator
@@ -216,10 +213,7 @@ def linkcode_resolve(
     except Exception:
         lineno = None
 
-    if lineno:
-        linespec = "#L%d-L%d" % (lineno, lineno + len(source) - 1)
-    else:
-        linespec = ""
+    linespec = "#L%d-L%d" % (lineno, lineno + len(source) - 1) if lineno else ""
 
     fn = relpath(fn, start=pathlib.Path(libtmux.__file__).parent)
 
diff --git a/pyproject.toml b/pyproject.toml
index eae982a34..f7624d730 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -129,6 +129,33 @@ exclude_lines = [
   "@overload( |$)",
 ]
 
+[tool.ruff]
+target-version = "py37"
+select = [
+  "E", # pycodestyle
+  "F", # pyflakes
+  "I", # isort
+  "UP",  # pyupgrade
+  "B", # flake8-bugbear
+  "C4", # flake8-comprehensions
+  "Q", # flake8-quotes
+  "PTH", # flake8-use-pathlib
+  "ERA", # eradicate
+  "SIM",  # flake8-simplify
+  "TRY", # Trycertatops
+  "PERF", # Perflint
+  "RUF" # Ruff-specific rules
+]
+
+[tool.ruff.isort]
+known-first-party = [
+  "libtmux"
+]
+combine-as-imports = true
+
+[tool.ruff.per-file-ignores]
+"*/__init__.py" = ["F401"]
+
 [build-system]
 requires = ["poetry_core>=1.0.0"]
 build-backend = "poetry.core.masonry.api"
diff --git a/src/libtmux/_internal/query_list.py b/src/libtmux/_internal/query_list.py
index 7fa3d4170..de5ea5078 100644
--- a/src/libtmux/_internal/query_list.py
+++ b/src/libtmux/_internal/query_list.py
@@ -59,11 +59,12 @@ def keygetter(
             elif hasattr(dct, sub_field):
                 dct = getattr(dct, sub_field)
 
-        return dct
     except Exception as e:
         traceback.print_stack()
         print(f"Above error was {e}")
-    return None
+        return None
+
+    return dct
 
 
 def parse_lookup(obj: "Mapping[str, Any]", path: str, lookup: str) -> Optional[Any]:
@@ -123,7 +124,7 @@ def lookup_icontains(
     if isinstance(data, str):
         return rhs.lower() in data.lower()
     if isinstance(data, Mapping):
-        return rhs.lower() in [k.lower() for k in data.keys()]
+        return rhs.lower() in [k.lower() for k in data]
 
     return False
 
@@ -183,7 +184,6 @@ def lookup_in(
             return rhs in data
         # TODO: Add a deep Mappingionary matcher
         # if isinstance(rhs, Mapping) and isinstance(data, Mapping):
-        #     return rhs.items() not in data.items()
     except Exception:
         return False
     return False
@@ -205,7 +205,6 @@ def lookup_nin(
             return rhs not in data
         # TODO: Add a deep Mappingionary matcher
         # if isinstance(rhs, Mapping) and isinstance(data, Mapping):
-        #     return rhs.items() not in data.items()
     except Exception:
         return False
     return False
@@ -246,6 +245,16 @@ def lookup_iregex(
 }
 
 
+class PKRequiredException(Exception):
+    def __init__(self, *args: object):
+        return super().__init__("items() require a pk_key exists")
+
+
+class OpNotFound(ValueError):
+    def __init__(self, op: str, *args: object):
+        return super().__init__(f"{op} not in LOOKUP_NAME_MAP")
+
+
 class QueryList(List[T]):
     """Filter list of object/dictionaries. For small, local datasets.
 
@@ -286,17 +295,13 @@ class QueryList(List[T]):
 
     def items(self) -> List[T]:
         if self.pk_key is None:
-            raise Exception("items() require a pk_key exists")
+            raise PKRequiredException()
         return [(getattr(item, self.pk_key), item) for item in self]
 
     def __eq__(
         self,
         other: object,
         # other: Union[
-        #     "QueryList[T]",
-        #     List[Mapping[str, str]],
-        #     List[Mapping[str, int]],
-        #     List[Mapping[str, Union[str, Mapping[str, Union[List[str], str]]]]],
         # ],
     ) -> bool:
         data = other
@@ -330,7 +335,7 @@ def filter_lookup(obj: Any) -> bool:
                     lhs, op = path.rsplit("__", 1)
 
                     if op not in LOOKUP_NAME_MAP:
-                        raise ValueError(f"{op} not in LOOKUP_NAME_MAP")
+                        raise OpNotFound(op=op)
                 except ValueError:
                     lhs = path
                     op = "exact"
diff --git a/src/libtmux/_vendor/version.py b/src/libtmux/_vendor/version.py
index 3cd40b965..0aac18ff4 100644
--- a/src/libtmux/_vendor/version.py
+++ b/src/libtmux/_vendor/version.py
@@ -62,6 +62,9 @@ class InvalidVersion(ValueError):
     libtmux._vendor.version.InvalidVersion: Invalid version: 'invalid'
     """
 
+    def __init__(self, version: str, *args: object):
+        return super().__init__(f"Invalid version: '{version}'")
+
 
 class _BaseVersion:
     _key: CmpKey
@@ -195,7 +198,7 @@ def __init__(self, version: str) -> None:
         # Validate the version and parse it into pieces
         match = self._regex.search(version)
         if not match:
-            raise InvalidVersion(f"Invalid version: '{version}'")
+            raise InvalidVersion(version=version)
 
         # Store the parsed out pieces of the version
         self._version = _Version(
diff --git a/src/libtmux/common.py b/src/libtmux/common.py
index eac5179bc..4c85a3550 100644
--- a/src/libtmux/common.py
+++ b/src/libtmux/common.py
@@ -151,7 +151,7 @@ def show_environment(self) -> Dict[str, Union[bool, str]]:
             elif len(_t) == 1:
                 vars_dict[_t[0]] = True
             else:
-                raise ValueError(f"unexpected variable {_t}")
+                raise exc.VariableUnpackingError(variable=_t)
 
         return vars_dict
 
@@ -172,7 +172,7 @@ def getenv(self, name: str) -> Optional[t.Union[str, bool]]:
         str
             Value of environment variable
         """
-        tmux_args: t.Tuple[t.Union[str, int], ...] = tuple()
+        tmux_args: t.Tuple[t.Union[str, int], ...] = ()
 
         tmux_args += ("show-environment",)
         if self._add_option:
@@ -188,7 +188,7 @@ def getenv(self, name: str) -> Optional[t.Union[str, bool]]:
             elif len(_t) == 1:
                 vars_dict[_t[0]] = True
             else:
-                raise ValueError(f"unexpected variable {_t}")
+                raise exc.VariableUnpackingError(variable=_t)
 
         return vars_dict.get(name)
 
@@ -242,8 +242,8 @@ def __init__(self, *args: t.Any, **kwargs: t.Any) -> None:
             )
             stdout, stderr = self.process.communicate()
             returncode = self.process.returncode
-        except Exception as e:
-            logger.error(f"Exception for {subprocess.list2cmdline(cmd)}: \n{e}")
+        except Exception:
+            logger.exception(f"Exception for {subprocess.list2cmdline(cmd)}")
             raise
 
         self.returncode = returncode
@@ -425,9 +425,10 @@ def has_minimum_version(raises: bool = True) -> bool:
     if get_version() < LooseVersion(TMUX_MIN_VERSION):
         if raises:
             raise exc.VersionTooLow(
-                "libtmux only supports tmux %s and greater. This system"
-                " has %s installed. Upgrade your tmux to use libtmux."
-                % (TMUX_MIN_VERSION, get_version())
+                "libtmux only supports tmux {} and greater. This system"
+                " has {} installed. Upgrade your tmux to use libtmux.".format(
+                    TMUX_MIN_VERSION, get_version()
+                )
             )
         else:
             return False
@@ -452,15 +453,11 @@ def session_check_name(session_name: t.Optional[str]) -> None:
         Invalid session name.
     """
     if session_name is None or len(session_name) == 0:
-        raise exc.BadSessionName("tmux session names may not be empty.")
+        raise exc.BadSessionName(reason="empty", session_name=session_name)
     elif "." in session_name:
-        raise exc.BadSessionName(
-            'tmux session name "%s" may not contain periods.', session_name
-        )
+        raise exc.BadSessionName(reason="contains periods", session_name=session_name)
     elif ":" in session_name:
-        raise exc.BadSessionName(
-            'tmux session name "%s" may not contain colons.', session_name
-        )
+        raise exc.BadSessionName(reason="contains colons", session_name=session_name)
 
 
 def handle_option_error(error: str) -> t.Type[exc.OptionError]:
diff --git a/src/libtmux/exc.py b/src/libtmux/exc.py
index e76c41263..0023cb3eb 100644
--- a/src/libtmux/exc.py
+++ b/src/libtmux/exc.py
@@ -4,6 +4,12 @@
 ~~~~~~~~~~~
 
 """
+import typing as t
+
+from libtmux._internal.query_list import ObjectDoesNotExist
+
+if t.TYPE_CHECKING:
+    from libtmux.neo import ListExtraArgs
 
 
 class LibTmuxException(Exception):
@@ -21,6 +27,25 @@ class TmuxCommandNotFound(LibTmuxException):
     """Application binary for tmux not found."""
 
 
+class TmuxObjectDoesNotExist(ObjectDoesNotExist):
+    """The query returned multiple objects when only one was expected."""
+
+    def __init__(
+        self,
+        obj_key: t.Optional[str] = None,
+        obj_id: t.Optional[str] = None,
+        list_cmd: t.Optional[str] = None,
+        list_extra_args: "t.Optional[ListExtraArgs]" = None,
+        *args: object,
+    ):
+        if all(arg is not None for arg in [obj_key, obj_id, list_cmd, list_extra_args]):
+            return super().__init__(
+                f"Could not find {obj_key}={obj_id} for {list_cmd} "
+                f'{list_extra_args if list_extra_args is not None else ""}'
+            )
+        return super().__init__("Could not find object")
+
+
 class VersionTooLow(LibTmuxException):
 
     """Raised if tmux below the minimum version to use libtmux."""
@@ -30,6 +55,14 @@ class BadSessionName(LibTmuxException):
 
     """Disallowed session name for tmux (empty, contains periods or colons)."""
 
+    def __init__(
+        self, reason: str, session_name: t.Optional[str] = None, *args: object
+    ):
+        msg = f"Bad session name: {reason}"
+        if session_name is not None:
+            msg += f" (session name: {session_name})"
+        return super().__init__(msg)
+
 
 class OptionError(LibTmuxException):
 
@@ -41,6 +74,14 @@ class UnknownOption(OptionError):
     """Option unknown to tmux show-option(s) or show-window-option(s)."""
 
 
+class UnknownColorOption(UnknownOption):
+
+    """Unknown color option."""
+
+    def __init__(self, *args: object):
+        return super().__init__("Server.colors must equal 88 or 256")
+
+
 class InvalidOption(OptionError):
 
     """Option invalid to tmux, introduced in tmux v2.4."""
@@ -54,3 +95,53 @@ class AmbiguousOption(OptionError):
 class WaitTimeout(LibTmuxException):
 
     """Function timed out without meeting condition"""
+
+
+class VariableUnpackingError(LibTmuxException):
+
+    """Error unpacking variable"""
+
+    def __init__(self, variable: t.Optional[t.Any] = None, *args: object):
+        return super().__init__(f"Unexpected variable: {variable!s}")
+
+
+class PaneError(LibTmuxException):
+    """Any type of pane related error"""
+
+
+class PaneNotFound(PaneError):
+    """Pane not found"""
+
+    def __init__(self, pane_id: t.Optional[str] = None, *args: object):
+        if pane_id is not None:
+            return super().__init__(f"Pane not found: {pane_id}")
+        return super().__init__("Pane not found")
+
+
+class WindowError(LibTmuxException):
+
+    """Any type of window related error"""
+
+
+class MultipleActiveWindows(WindowError):
+
+    """Multiple active windows"""
+
+    def __init__(self, count: int, *args: object):
+        return super().__init__(f"Multiple active windows: {count} found")
+
+
+class NoActiveWindow(WindowError):
+
+    """No active window found"""
+
+    def __init__(self, *args: object):
+        return super().__init__("No active windows found")
+
+
+class NoWindowsExist(WindowError):
+
+    """No windows exist for object"""
+
+    def __init__(self, *args: object):
+        return super().__init__("No windows exist for object")
diff --git a/src/libtmux/formats.py b/src/libtmux/formats.py
index 6f36799f1..eff1d7fed 100644
--- a/src/libtmux/formats.py
+++ b/src/libtmux/formats.py
@@ -41,14 +41,12 @@
 ]
 
 WINDOW_FORMATS = [
-    # format_window()
     "window_id",
     "window_name",
     "window_width",
     "window_height",
     "window_layout",
     "window_panes",
-    # format_winlink()
     "window_index",
     "window_flags",
     "window_active",
diff --git a/src/libtmux/neo.py b/src/libtmux/neo.py
index 70267b07d..9609e1e32 100644
--- a/src/libtmux/neo.py
+++ b/src/libtmux/neo.py
@@ -3,7 +3,6 @@
 import typing as t
 
 from libtmux import exc
-from libtmux._internal.query_list import ObjectDoesNotExist
 from libtmux.common import tmux_cmd
 from libtmux.formats import FORMAT_SEPARATOR
 
@@ -40,16 +39,13 @@ class Obj:
     alternate_saved_x: t.Union[str, None] = None
     alternate_saved_y: t.Union[str, None] = None
     # See QUIRK_TMUX_3_1_X_0001
-    # buffer_created: t.Union[str, None] = None
     buffer_name: t.Union[str, None] = None
     buffer_sample: t.Union[str, None] = None
     buffer_size: t.Union[str, None] = None
     # See QUIRK_TMUX_3_1_X_0001
-    # client_activity: t.Union[str, None] = None
     client_cell_height: t.Union[str, None] = None
     client_cell_width: t.Union[str, None] = None
     # See QUIRK_TMUX_3_1_X_0001
-    # client_created: t.Union[str, None] = None
     client_discarded: t.Union[str, None] = None
     client_flags: t.Union[str, None] = None
     client_height: t.Union[str, None] = None
@@ -182,11 +178,13 @@ def _refresh(
 
 
 def fetch_objs(
-    server: "Server", list_cmd: "ListCmd", list_extra_args: "ListExtraArgs" = None
+    server: "Server",
+    list_cmd: "ListCmd",
+    list_extra_args: "t.Optional[ListExtraArgs]" = None,
 ) -> OutputsRaw:
     formats = list(Obj.__dataclass_fields__.keys())
 
-    cmd_args: t.List[t.Union[str, int]] = list()
+    cmd_args: t.List[t.Union[str, int]] = []
 
     if server.socket_name:
         cmd_args.insert(0, f"-L{server.socket_name}")
@@ -229,7 +227,7 @@ def fetch_obj(
     obj_key: str,
     obj_id: str,
     list_cmd: "ListCmd" = "list-panes",
-    list_extra_args: "ListExtraArgs" = None,
+    list_extra_args: "t.Optional[ListExtraArgs]" = None,
 ) -> OutputRaw:
     obj_formatters_filtered = fetch_objs(
         server=server, list_cmd=list_cmd, list_extra_args=list_extra_args
@@ -241,9 +239,11 @@ def fetch_obj(
             obj = _obj
 
     if obj is None:
-        raise ObjectDoesNotExist(
-            f"Could not find {obj_key}={obj_id} for {list_cmd} "
-            f'{list_extra_args if list_extra_args is not None else ""}'
+        raise exc.TmuxObjectDoesNotExist(
+            obj_key=obj_key,
+            obj_id=obj_id,
+            list_cmd=list_cmd,
+            list_extra_args=list_extra_args,
         )
 
     assert obj is not None
diff --git a/src/libtmux/pane.py b/src/libtmux/pane.py
index cd876c04e..6ec3f8092 100644
--- a/src/libtmux/pane.py
+++ b/src/libtmux/pane.py
@@ -103,7 +103,6 @@ def session(self) -> "Session":
         return self.window.session
 
     #
-    # Command (pane-scoped)
     #
     def cmd(self, cmd: str, *args: t.Any, **kwargs: t.Any) -> tmux_cmd:
         """Return :meth:`Server.cmd` defaulting to ``target_pane`` as target.
@@ -114,12 +113,11 @@ def cmd(self, cmd: str, *args: t.Any, **kwargs: t.Any) -> tmux_cmd:
         ``args`` will override using the object's ``pane_id`` as target.
         """
         if not any(arg.startswith("-t") for arg in args):
-            args = ("-t", self.pane_id) + args
+            args = ("-t", self.pane_id, *args)
 
         return self.server.cmd(cmd, *args, **kwargs)
 
     #
-    # Commands (tmux-like)
     #
     def resize_pane(self, *args: t.Any, **kwargs: t.Any) -> "Pane":
         """
@@ -174,14 +172,14 @@ def capture_pane(
             Zero is the first line of the visible pane.
             Positive numbers are lines in the visible pane.
             Negative numbers are lines in the history.
-            ‘-’ is the start of the history.
+            `-` is the start of the history.
             Default: None
         end: [str,int]
             Specify the ending line number.
             Zero is the first line of the visible pane.
             Positive numbers are lines in the visible pane.
             Negative numbers are lines in the history.
-            ‘-’ is the end of the visible pane
+            `-` is the end of the visible pane
             Default: None
         """
         cmd = ["capture-pane", "-p"]
@@ -277,7 +275,6 @@ def display_message(
         return None
 
     #
-    # Commands ("climber"-helpers)
     #
     # These are commands that climb to the parent scope's methods with
     # additional scoped window info.
@@ -293,7 +290,7 @@ def select_pane(self) -> "Pane":
         assert isinstance(self.pane_id, str)
         pane = self.window.select_pane(self.pane_id)
         if pane is None:
-            raise exc.LibTmuxException(f"Pane not found: {self}")
+            raise exc.PaneNotFound(pane_id=self.pane_id)
         return pane
 
     def split_window(
@@ -326,7 +323,6 @@ def split_window(
         )
 
     #
-    # Commands (helpers)
     #
     def set_width(self, width: int) -> "Pane":
         """
@@ -380,7 +376,7 @@ def __eq__(self, other: object) -> bool:
         return self.pane_id == other.pane_id
 
     def __repr__(self) -> str:
-        return "{}({} {})".format(self.__class__.__name__, self.pane_id, self.window)
+        return f"{self.__class__.__name__}({self.pane_id} {self.window})"
 
     #
     # Aliases
@@ -440,12 +436,12 @@ def get(self, key: str, default: t.Optional[t.Any] = None) -> t.Any:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn("Pane.get() is deprecated")
+        warnings.warn("Pane.get() is deprecated", stacklevel=2)
         return getattr(self, key, default)
 
     def __getitem__(self, key: str) -> t.Any:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn(f"Item lookups, e.g. pane['{key}'] is deprecated")
+        warnings.warn(f"Item lookups, e.g. pane['{key}'] is deprecated", stacklevel=2)
         return getattr(self, key)
diff --git a/src/libtmux/pytest_plugin.py b/src/libtmux/pytest_plugin.py
index f24bfdbd0..0cfb1c594 100644
--- a/src/libtmux/pytest_plugin.py
+++ b/src/libtmux/pytest_plugin.py
@@ -1,3 +1,4 @@
+import contextlib
 import getpass
 import logging
 import os
@@ -80,7 +81,7 @@ def clear_env(monkeypatch: pytest.MonkeyPatch) -> None:
 
     tmux show-environment tests were being interrupted due to a lot of crazy env vars.
     """
-    for k, v in os.environ.items():
+    for k in os.environ:
         if not any(
             needle in k.lower()
             for needle in [
@@ -224,10 +225,7 @@ def session(
 
     TEST_SESSION_NAME = get_test_session_name(server=server)
 
-    try:
-        session = server.new_session(session_name=TEST_SESSION_NAME, **session_params)
-    except exc.LibTmuxException as e:
-        raise e
+    session = server.new_session(session_name=TEST_SESSION_NAME, **session_params)
 
     """
     Make sure that tmuxp can :ref:`test_builder_visually` and switches to
@@ -236,16 +234,13 @@ def session(
     session_id = session.session_id
     assert session_id is not None
 
-    try:
+    with contextlib.suppress(exc.LibTmuxException):
         server.switch_client(target_session=session_id)
-    except exc.LibTmuxException:
-        # server.attach_session(session.get('session_id'))
-        pass
 
     for old_test_session in old_test_sessions:
         logger.debug(f"Old test test session {old_test_session} found. Killing it.")
         server.kill_session(old_test_session)
-    assert TEST_SESSION_NAME == session.session_name
+    assert session.session_name == TEST_SESSION_NAME
     assert TEST_SESSION_NAME != "tmuxp"
 
     return session
diff --git a/src/libtmux/server.py b/src/libtmux/server.py
index a281d202b..5f8029492 100644
--- a/src/libtmux/server.py
+++ b/src/libtmux/server.py
@@ -143,9 +143,9 @@ def is_alive(self) -> bool:
         """
         try:
             res = self.cmd("list-sessions")
-            return res.returncode == 0
         except Exception:
             return False
+        return res.returncode == 0
 
     def raise_if_dead(self) -> None:
         """Raise if server not connected.
@@ -169,7 +169,7 @@ def raise_if_dead(self) -> None:
         if self.config_file:
             cmd_args.insert(0, f"-f{self.config_file}")
 
-        subprocess.check_call([tmux_bin] + cmd_args)
+        subprocess.check_call([tmux_bin, *cmd_args])
 
     #
     # Command
@@ -207,7 +207,7 @@ def cmd(self, *args: t.Any, **kwargs: t.Any) -> tmux_cmd:
             elif self.colors == 88:
                 cmd_args.insert(0, "-8")
             else:
-                raise ValueError("Server.colors must equal 88 or 256")
+                raise exc.UnknownColorOption()
 
         return tmux_cmd(*cmd_args, **kwargs)
 
@@ -227,7 +227,7 @@ def attached_sessions(self) -> t.List[Session]:
         """
         try:
             sessions = self.sessions
-            attached_sessions = list()
+            attached_sessions = []
 
             for session in sessions:
                 attached = session.session_attached
@@ -238,10 +238,9 @@ def attached_sessions(self) -> t.List[Session]:
                 else:
                     continue
 
-            return attached_sessions
-            # return [Session(**s) for s in attached_sessions] or None
         except Exception:
             return []
+        return attached_sessions
 
     def has_session(self, target_session: str, exact: bool = True) -> bool:
         """
@@ -339,7 +338,7 @@ def attach_session(self, target_session: t.Optional[str] = None) -> None:
         """
         session_check_name(target_session)
 
-        tmux_args: t.Tuple[str, ...] = tuple()
+        tmux_args: t.Tuple[str, ...] = ()
         if target_session:
             tmux_args += ("-t%s" % target_session,)
 
@@ -513,7 +512,7 @@ def sessions(self) -> QueryList[Session]:  # type:ignore
                 list_cmd="list-sessions",
                 server=self,
             ):
-                sessions.append(Session(server=self, **obj))
+                sessions.append(Session(server=self, **obj))  # noqa: PERF401
         except Exception:
             pass
 
@@ -527,13 +526,14 @@ def windows(self) -> QueryList[Window]:  # type:ignore
         :meth:`.windows.get() <libtmux._internal.query_list.QueryList.get()>` and
         :meth:`.windows.filter() <libtmux._internal.query_list.QueryList.filter()>`
         """
-        windows: t.List["Window"] = []
-        for obj in fetch_objs(
-            list_cmd="list-windows",
-            list_extra_args=("-a",),
-            server=self,
-        ):
-            windows.append(Window(server=self, **obj))
+        windows: t.List["Window"] = [
+            Window(server=self, **obj)
+            for obj in fetch_objs(
+                list_cmd="list-windows",
+                list_extra_args=("-a",),
+                server=self,
+            )
+        ]
 
         return QueryList(windows)
 
@@ -545,13 +545,14 @@ def panes(self) -> QueryList[Pane]:  # type:ignore
         :meth:`.panes.get() <libtmux._internal.query_list.QueryList.get()>` and
         :meth:`.panes.filter() <libtmux._internal.query_list.QueryList.filter()>`
         """
-        panes: t.List["Pane"] = []
-        for obj in fetch_objs(
-            list_cmd="list-panes",
-            list_extra_args=["-s"],
-            server=self,
-        ):
-            panes.append(Pane(server=self, **obj))
+        panes: t.List["Pane"] = [
+            Pane(server=self, **obj)
+            for obj in fetch_objs(
+                list_cmd="list-panes",
+                list_extra_args=["-s"],
+                server=self,
+            )
+        ]
 
         return QueryList(panes)
 
@@ -572,10 +573,7 @@ def __repr__(self) -> str:
                 f"(socket_name={getattr(self, 'socket_name', 'default')})"
             )
         elif self.socket_path is not None:
-            return (
-                f"{self.__class__.__name__}"
-                f"(socket_path={getattr(self, 'socket_path')})"
-            )
+            return f"{self.__class__.__name__}" f"(socket_path={self.socket_path})"
         return f"{self.__class__.__name__}" f"(socket_path=/tmp/tmux-1000/default)"
 
     #
@@ -592,7 +590,7 @@ def _list_panes(self) -> t.List[PaneDict]:
 
         .. deprecated:: 0.16
         """
-        warnings.warn("Server._list_panes() is deprecated")
+        warnings.warn("Server._list_panes() is deprecated", stacklevel=2)
         return [p.__dict__ for p in self.panes]
 
     def _update_panes(self) -> "Server":
@@ -605,7 +603,7 @@ def _update_panes(self) -> "Server":
 
         .. deprecated:: 0.16
         """
-        warnings.warn("Server._update_panes() is deprecated")
+        warnings.warn("Server._update_panes() is deprecated", stacklevel=2)
         self._list_panes()
         return self
 
@@ -613,14 +611,14 @@ def get_by_id(self, id: str) -> t.Optional[Session]:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn("Server.get_by_id() is deprecated")
+        warnings.warn("Server.get_by_id() is deprecated", stacklevel=2)
         return self.sessions.get(session_id=id, default=None)
 
     def where(self, kwargs: t.Dict[str, t.Any]) -> t.List[Session]:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn("Server.find_where() is deprecated")
+        warnings.warn("Server.find_where() is deprecated", stacklevel=2)
         try:
             return self.sessions.filter(**kwargs)
         except IndexError:
@@ -630,7 +628,7 @@ def find_where(self, kwargs: t.Dict[str, t.Any]) -> t.Optional[Session]:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn("Server.find_where() is deprecated")
+        warnings.warn("Server.find_where() is deprecated", stacklevel=2)
         return self.sessions.get(default=None, **kwargs)
 
     def _list_windows(self) -> t.List[WindowDict]:
@@ -643,7 +641,7 @@ def _list_windows(self) -> t.List[WindowDict]:
 
         .. deprecated:: 0.16
         """
-        warnings.warn("Server._list_windows() is deprecated")
+        warnings.warn("Server._list_windows() is deprecated", stacklevel=2)
         return [w.__dict__ for w in self.windows]
 
     def _update_windows(self) -> "Server":
@@ -651,7 +649,7 @@ def _update_windows(self) -> "Server":
 
         .. deprecated:: 0.16
         """
-        warnings.warn("Server._update_windows() is deprecated")
+        warnings.warn("Server._update_windows() is deprecated", stacklevel=2)
         self._list_windows()
         return self
 
@@ -661,14 +659,14 @@ def _sessions(self) -> t.List[SessionDict]:
 
         .. deprecated:: 0.16
         """
-        warnings.warn("Server._sessions is deprecated")
+        warnings.warn("Server._sessions is deprecated", stacklevel=2)
         return self._list_sessions()
 
     def _list_sessions(self) -> t.List["SessionDict"]:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn("Server._list_sessions() is deprecated")
+        warnings.warn("Server._list_sessions() is deprecated", stacklevel=2)
         return [s.__dict__ for s in self.sessions]
 
     def list_sessions(self) -> t.List[Session]:
@@ -680,7 +678,7 @@ def list_sessions(self) -> t.List[Session]:
         -------
         list of :class:`Session`
         """
-        warnings.warn("Server.list_sessions is deprecated")
+        warnings.warn("Server.list_sessions is deprecated", stacklevel=2)
         return self.sessions
 
     @property
@@ -689,5 +687,5 @@ def children(self) -> QueryList["Session"]:  # type:ignore
 
         .. deprecated:: 0.16
         """
-        warnings.warn("Server.children is deprecated")
+        warnings.warn("Server.children is deprecated", stacklevel=2)
         return self.sessions
diff --git a/src/libtmux/session.py b/src/libtmux/session.py
index 1793a687f..d1d688d71 100644
--- a/src/libtmux/session.py
+++ b/src/libtmux/session.py
@@ -6,7 +6,7 @@
 """
 import dataclasses
 import logging
-import os
+import pathlib
 import typing as t
 import warnings
 
@@ -101,14 +101,15 @@ def windows(self) -> QueryList["Window"]:  # type:ignore
         :meth:`.windows.get() <libtmux._internal.query_list.QueryList.get()>` and
         :meth:`.windows.filter() <libtmux._internal.query_list.QueryList.filter()>`
         """
-        windows: t.List["Window"] = []
-        for obj in fetch_objs(
-            list_cmd="list-windows",
-            list_extra_args=["-t", str(self.session_id)],
-            server=self.server,
-        ):
-            if obj.get("session_id") == self.session_id:
-                windows.append(Window(server=self.server, **obj))
+        windows: t.List["Window"] = [
+            Window(server=self.server, **obj)
+            for obj in fetch_objs(
+                list_cmd="list-windows",
+                list_extra_args=["-t", str(self.session_id)],
+                server=self.server,
+            )
+            if obj.get("session_id") == self.session_id
+        ]
 
         return QueryList(windows)
 
@@ -120,14 +121,15 @@ def panes(self) -> QueryList["Pane"]:  # type:ignore
         :meth:`.panes.get() <libtmux._internal.query_list.QueryList.get()>` and
         :meth:`.panes.filter() <libtmux._internal.query_list.QueryList.filter()>`
         """
-        panes: t.List["Pane"] = []
-        for obj in fetch_objs(
-            list_cmd="list-panes",
-            list_extra_args=["-s", "-t", str(self.session_id)],
-            server=self.server,
-        ):
-            if obj.get("session_id") == self.session_id:
-                panes.append(Pane(server=self.server, **obj))
+        panes: t.List["Pane"] = [
+            Pane(server=self.server, **obj)
+            for obj in fetch_objs(
+                list_cmd="list-panes",
+                list_extra_args=["-s", "-t", str(self.session_id)],
+                server=self.server,
+            )
+            if obj.get("session_id") == self.session_id
+        ]
 
         return QueryList(panes)
 
@@ -151,7 +153,7 @@ def cmd(self, *args: t.Any, **kwargs: t.Any) -> tmux_cmd:
         # if -t is not set in any arg yet
         if not any("-t" in str(x) for x in args):
             # insert -t immediately after 1st arg, as per tmux format
-            new_args: t.Tuple[str, ...] = tuple()
+            new_args: t.Tuple[str, ...] = ()
             new_args += (args[0],)
             assert isinstance(self.session_id, str)
             new_args += (
@@ -163,7 +165,6 @@ def cmd(self, *args: t.Any, **kwargs: t.Any) -> tmux_cmd:
         return self.server.cmd(*args, **kwargs)
 
     #
-    # Commands (tmux-like)
     #
     def set_option(
         self, option: str, value: t.Union[str, int], _global: bool = False
@@ -197,7 +198,7 @@ def set_option(
         elif isinstance(value, bool) and not value:
             value = "off"
 
-        tmux_args: t.Tuple[t.Union[str, int], ...] = tuple()
+        tmux_args: t.Tuple[t.Union[str, int], ...] = ()
 
         if _global:
             tmux_args += ("-g",)
@@ -240,7 +241,7 @@ def show_options(
         Uses ``_global`` for keyword name instead of ``global`` to avoid
         colliding with reserved keyword.
         """
-        tmux_args: t.Tuple[str, ...] = tuple()
+        tmux_args: t.Tuple[str, ...] = ()
 
         if _global:
             tmux_args += ("-g",)
@@ -288,7 +289,7 @@ def show_option(
         Test and return True/False for on/off string.
         """
 
-        tmux_args: t.Tuple[str, ...] = tuple()
+        tmux_args: t.Tuple[str, ...] = ()
 
         if _global:
             tmux_args += ("-g",)
@@ -303,7 +304,7 @@ def show_option(
         if not len(cmd.stdout):
             return None
 
-        value_raw: t.List[str] = [item.split(" ") for item in cmd.stdout][0]
+        value_raw: t.List[str] = next(item.split(" ") for item in cmd.stdout)
 
         assert isinstance(value_raw[0], str)
         assert isinstance(value_raw[1], str)
@@ -355,23 +356,19 @@ def attached_window(self) -> "Window":
         """
         Return active :class:`Window` object.
         """
-        active_windows = []
-        for window in self.windows:
-            # for now window_active is a unicode
-            if window.window_active == "1":
-                active_windows.append(window)
+        active_windows = [
+            window for window in self.windows if window.window_active == "1"
+        ]
 
         if len(active_windows) == 1:
-            return list(active_windows)[0]
+            return next(iter(active_windows))
         elif len(active_windows) == 0:
-            raise exc.LibTmuxException("no active windows found")
+            raise exc.NoActiveWindow()
         else:
-            raise exc.LibTmuxException(
-                "multiple active windows found. %s" % active_windows
-            )
+            raise exc.MultipleActiveWindows(count=len(active_windows))
 
         if len(self._windows) == 0:
-            raise exc.LibTmuxException("No Windows")
+            raise exc.NoWindowsExist()
 
     def attach_session(self) -> "Session":
         """Return ``$ tmux attach-session`` aka alias: ``$ tmux attach``."""
@@ -476,7 +473,7 @@ def new_window(
         -------
         :class:`Window`
         """
-        window_args: t.Tuple[str, ...] = tuple()
+        window_args: t.Tuple[str, ...] = ()
 
         if not attach:
             window_args += ("-d",)
@@ -485,8 +482,8 @@ def new_window(
 
         if start_directory:
             # as of 2014-02-08 tmux 1.9-dev doesn't expand ~ in new-window -c.
-            start_directory = os.path.expanduser(start_directory)
-            window_args += ("-c%s" % start_directory,)
+            start_directory = pathlib.Path(start_directory).expanduser()
+            window_args += (f"-c{start_directory}",)
 
         window_args += ("-F#{window_id}",)  # output
         if window_name is not None and isinstance(window_name, str):
@@ -494,8 +491,7 @@ def new_window(
 
         window_args += (
             # empty string for window_index will use the first one available
-            "-t%s:%s"
-            % (self.session_id, window_index),
+            f"-t{self.session_id}:{window_index}",
         )
 
         if environment:
@@ -601,28 +597,30 @@ def get(self, key: str, default: t.Optional[t.Any] = None) -> t.Any:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn("Session.get() is deprecated")
+        warnings.warn("Session.get() is deprecated", stacklevel=2)
         return getattr(self, key, default)
 
     def __getitem__(self, key: str) -> t.Any:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn(f"Item lookups, e.g. session['{key}'] is deprecated")
+        warnings.warn(
+            f"Item lookups, e.g. session['{key}'] is deprecated", stacklevel=2
+        )
         return getattr(self, key)
 
     def get_by_id(self, id: str) -> t.Optional[Window]:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn("Session.get_by_id() is deprecated")
+        warnings.warn("Session.get_by_id() is deprecated", stacklevel=2)
         return self.windows.get(window_id=id, default=None)
 
     def where(self, kwargs: t.Dict[str, t.Any]) -> t.List[Window]:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn("Session.where() is deprecated")
+        warnings.warn("Session.where() is deprecated", stacklevel=2)
         try:
             return self.windows.filter(**kwargs)
         except IndexError:
@@ -632,14 +630,14 @@ def find_where(self, kwargs: t.Dict[str, t.Any]) -> t.Optional[Window]:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn("Session.find_where() is deprecated")
+        warnings.warn("Session.find_where() is deprecated", stacklevel=2)
         return self.windows.get(default=None, **kwargs)
 
     def _list_windows(self) -> t.List["WindowDict"]:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn("Session._list_windows() is deprecated")
+        warnings.warn("Session._list_windows() is deprecated", stacklevel=2)
         return [w.__dict__ for w in self.windows]
 
     @property
@@ -648,7 +646,7 @@ def _windows(self) -> t.List["WindowDict"]:
 
         .. deprecated:: 0.16
         """
-        warnings.warn("Session._windows is deprecated")
+        warnings.warn("Session._windows is deprecated", stacklevel=2)
         return self._list_windows()
 
     def list_windows(self) -> t.List["Window"]:
@@ -656,7 +654,7 @@ def list_windows(self) -> t.List["Window"]:
 
         .. deprecated:: 0.16
         """
-        warnings.warn("Session.list_windows() is deprecated")
+        warnings.warn("Session.list_windows() is deprecated", stacklevel=2)
         return self.windows
 
     @property
@@ -665,5 +663,5 @@ def children(self) -> QueryList["Window"]:  # type:ignore
 
         .. deprecated:: 0.16
         """
-        warnings.warn("Session.children is deprecated")
+        warnings.warn("Session.children is deprecated", stacklevel=2)
         return self.windows
diff --git a/src/libtmux/test.py b/src/libtmux/test.py
index 861ac6dda..57cea49b0 100644
--- a/src/libtmux/test.py
+++ b/src/libtmux/test.py
@@ -2,6 +2,7 @@
 import contextlib
 import logging
 import os
+import pathlib
 import random
 import time
 import types
@@ -47,9 +48,9 @@ def __next__(self) -> str:
 
 
 namer = RandomStrSequence()
-current_dir = os.path.abspath(os.path.dirname(__file__))
-example_dir = os.path.abspath(os.path.join(current_dir, "..", "examples"))
-fixtures_dir = os.path.realpath(os.path.join(current_dir, "fixtures"))
+current_dir = pathlib.Path(__file__)
+example_dir = current_dir.parent / "examples"
+fixtures_dir = current_dir / "fixtures"
 
 
 def retry_until(
@@ -305,7 +306,7 @@ class EnvironmentVarGuard:
     def __init__(self) -> None:
         self._environ = os.environ
         self._unset: t.Set[str] = set()
-        self._reset: t.Dict[str, str] = dict()
+        self._reset: t.Dict[str, str] = {}
 
     def set(self, envvar: str, value: str) -> None:
         if envvar not in self._environ:
diff --git a/src/libtmux/window.py b/src/libtmux/window.py
index 072707a3d..4e3b450c3 100644
--- a/src/libtmux/window.py
+++ b/src/libtmux/window.py
@@ -6,7 +6,7 @@
 """
 import dataclasses
 import logging
-import os
+import pathlib
 import shlex
 import typing as t
 import warnings
@@ -113,19 +113,19 @@ def panes(self) -> QueryList["Pane"]:  # type: ignore
         :meth:`.panes.get() <libtmux._internal.query_list.QueryList.get()>` and
         :meth:`.panes.filter() <libtmux._internal.query_list.QueryList.filter()>`
         """
-        panes: t.List["Pane"] = []
-        for obj in fetch_objs(
-            list_cmd="list-panes",
-            list_extra_args=["-t", str(self.window_id)],
-            server=self.server,
-        ):
-            if obj.get("window_id") == self.window_id:
-                panes.append(Pane(server=self.server, **obj))
+        panes: t.List["Pane"] = [
+            Pane(server=self.server, **obj)
+            for obj in fetch_objs(
+                list_cmd="list-panes",
+                list_extra_args=["-t", str(self.window_id)],
+                server=self.server,
+            )
+            if obj.get("window_id") == self.window_id
+        ]
 
         return QueryList(panes)
 
     #
-    # Command (pane-scoped)
     #
     def cmd(self, cmd: str, *args: t.Any, **kwargs: t.Any) -> tmux_cmd:
         """Return :meth:`Server.cmd` defaulting to ``target_window`` as target.
@@ -136,12 +136,11 @@ def cmd(self, cmd: str, *args: t.Any, **kwargs: t.Any) -> tmux_cmd:
         ``args`` will override using the object's ``window_id`` as target.
         """
         if not any(arg.startswith("-t") for arg in args):
-            args = ("-t", self.window_id) + args
+            args = ("-t", self.window_id, *args)
 
         return self.server.cmd(cmd, *args, **kwargs)
 
     #
-    # Commands (tmux-like)
     #
     def select_pane(self, target_pane: t.Union[str, int]) -> t.Optional["Pane"]:
         """
@@ -219,21 +218,18 @@ def split_window(
         """
         tmux_formats = ["#{pane_id}" + FORMAT_SEPARATOR]
 
-        # '-t%s' % self.attached_pane.get('pane_id'),
         # 2013-10-18 LOOK AT THIS, rm'd it..
-        tmux_args: t.Tuple[str, ...] = tuple()
+        tmux_args: t.Tuple[str, ...] = ()
 
         if target is not None:
             tmux_args += ("-t%s" % target,)
         else:
             if len(self.panes):
                 tmux_args += (
-                    "-t%s:%s.%s"
-                    % (self.session_id, self.window_id, self.panes[0].pane_index),
+                    f"-t{self.session_id}:{self.window_id}.{self.panes[0].pane_index}",
                 )
             else:
-                tmux_args += ("-t%s:%s" % (self.session_id, self.window_id),)
-            # tmux_args += ("-t%s" % self.panes[0].pane_id,)
+                tmux_args += (f"-t{self.session_id}:{self.window_id}",)
 
         if vertical:
             tmux_args += ("-v",)
@@ -245,10 +241,10 @@ def split_window(
 
         tmux_args += ("-P", "-F%s" % "".join(tmux_formats))  # output
 
-        if start_directory:
+        if start_directory is not None:
             # as of 2014-02-08 tmux 1.9-dev doesn't expand ~ in new-window -c.
-            start_directory = os.path.expanduser(start_directory)
-            tmux_args += ("-c%s" % start_directory,)
+            start_path = pathlib.Path(start_directory).expanduser()
+            tmux_args += (f"-c{start_path}",)
 
         if not attach:
             tmux_args += ("-d",)
@@ -313,7 +309,7 @@ def select_layout(self, layout: t.Optional[str] = None) -> "Window":
             'custom'
                 custom dimensions (see :term:`tmux(1)` manpages).
         """
-        cmd = ["select-layout", "-t{}:{}".format(self.session_id, self.window_index)]
+        cmd = ["select-layout", f"-t{self.session_id}:{self.window_index}"]
 
         if layout:  # tmux allows select-layout without args
             cmd.append(layout)
@@ -349,7 +345,7 @@ def set_window_option(self, option: str, value: t.Union[int, str]) -> "Window":
 
         cmd = self.cmd(
             "set-window-option",
-            "-t{}:{}".format(self.session_id, self.window_index),
+            f"-t{self.session_id}:{self.window_index}",
             option,
             value,
         )
@@ -375,7 +371,7 @@ def show_window_options(self, g: t.Optional[bool] = False) -> "WindowOptionDict"
         g : str, optional
             Pass ``-g`` flag for global variable, default False.
         """
-        tmux_args: t.Tuple[str, ...] = tuple()
+        tmux_args: t.Tuple[str, ...] = ()
 
         if g:
             tmux_args += ("-g",)
@@ -419,7 +415,7 @@ def show_window_option(
         :exc:`exc.OptionError`, :exc:`exc.UnknownOption`,
         :exc:`exc.InvalidOption`, :exc:`exc.AmbiguousOption`
         """
-        tmux_args: t.Tuple[t.Union[str, int], ...] = tuple()
+        tmux_args: t.Tuple[t.Union[str, int], ...] = ()
 
         if g:
             tmux_args += ("-g",)
@@ -436,7 +432,7 @@ def show_window_option(
         if not len(window_options_output):
             return None
 
-        value_raw = [shlex.split(item) for item in window_options_output][0]
+        value_raw = next(shlex.split(item) for item in window_options_output)
 
         value: t.Union[str, int] = (
             int(value_raw[1]) if value_raw[1].isdigit() else value_raw[1]
@@ -474,8 +470,8 @@ def rename_window(self, new_name: str) -> "Window":
         try:
             self.cmd("rename-window", new_name)
             self.window_name = new_name
-        except Exception as e:
-            logger.error(e)
+        except Exception:
+            logger.exception(f"Error renaming window to {new_name}")
 
         self.refresh()
 
@@ -486,7 +482,7 @@ def kill_window(self) -> None:
 
         proc = self.cmd(
             "kill-window",
-            "-t{}:{}".format(self.session_id, self.window_index),
+            f"-t{self.session_id}:{self.window_index}",
         )
 
         if proc.stderr:
@@ -510,7 +506,7 @@ def move_window(
         session = session or self.session_id
         proc = self.cmd(
             "move-window",
-            "-s{}:{}".format(self.session_id, self.window_index),
+            f"-s{self.session_id}:{self.window_index}",
             f"-t{session}:{destination}",
         )
 
@@ -635,28 +631,28 @@ def get(self, key: str, default: t.Optional[t.Any] = None) -> t.Any:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn("Window.get() is deprecated")
+        warnings.warn("Window.get() is deprecated", stacklevel=2)
         return getattr(self, key, default)
 
     def __getitem__(self, key: str) -> t.Any:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn(f"Item lookups, e.g. window['{key}'] is deprecated")
+        warnings.warn(f"Item lookups, e.g. window['{key}'] is deprecated", stacklevel=2)
         return getattr(self, key)
 
     def get_by_id(self, id: str) -> t.Optional[Pane]:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn("Window.get_by_id() is deprecated")
+        warnings.warn("Window.get_by_id() is deprecated", stacklevel=2)
         return self.panes.get(pane_id=id, default=None)
 
     def where(self, kwargs: t.Dict[str, t.Any]) -> t.List[Pane]:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn("Window.where() is deprecated")
+        warnings.warn("Window.where() is deprecated", stacklevel=2)
         try:
             return self.panes.filter(**kwargs)
         except IndexError:
@@ -666,14 +662,14 @@ def find_where(self, kwargs: t.Dict[str, t.Any]) -> t.Optional[Pane]:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn("Window.find_where() is deprecated")
+        warnings.warn("Window.find_where() is deprecated", stacklevel=2)
         return self.panes.get(default=None, **kwargs)
 
     def _list_panes(self) -> t.List[PaneDict]:
         """
         .. deprecated:: 0.16
         """
-        warnings.warn("Window._list_panes() is deprecated")
+        warnings.warn("Window._list_panes() is deprecated", stacklevel=2)
         return [pane.__dict__ for pane in self.panes]
 
     @property
@@ -682,7 +678,7 @@ def _panes(self) -> t.List[PaneDict]:
 
         .. deprecated:: 0.16
         """
-        warnings.warn("_panes is deprecated")
+        warnings.warn("_panes is deprecated", stacklevel=2)
         return self._list_panes()
 
     def list_panes(self) -> t.List["Pane"]:
@@ -690,7 +686,7 @@ def list_panes(self) -> t.List["Pane"]:
 
         .. deprecated:: 0.16
         """
-        warnings.warn("list_panes() is deprecated")
+        warnings.warn("list_panes() is deprecated", stacklevel=2)
         return self.panes
 
     @property
@@ -699,5 +695,5 @@ def children(self) -> QueryList["Pane"]:  # type:ignore
 
         .. deprecated:: 0.16
         """
-        warnings.warn("Server.children is deprecated")
+        warnings.warn("Server.children is deprecated", stacklevel=2)
         return self.panes
diff --git a/tests/legacy_api/test_common.py b/tests/legacy_api/test_common.py
index 7e6db2c43..158049530 100644
--- a/tests/legacy_api/test_common.py
+++ b/tests/legacy_api/test_common.py
@@ -31,7 +31,7 @@
 
 def test_allows_master_version(monkeypatch: pytest.MonkeyPatch) -> None:
     class Hi:
-        stdout = ["tmux master"]
+        stdout: t.ClassVar = ["tmux master"]
         stderr = None
 
     def mock_tmux_cmd(*args: t.Any, **kwargs: t.Any) -> Hi:
@@ -51,7 +51,7 @@ def test_allows_next_version(monkeypatch: pytest.MonkeyPatch) -> None:
     TMUX_NEXT_VERSION = str(float(TMUX_MAX_VERSION) + 0.1)
 
     class Hi:
-        stdout = [f"tmux next-{TMUX_NEXT_VERSION}"]
+        stdout: t.ClassVar = [f"tmux next-{TMUX_NEXT_VERSION}"]
         stderr = None
 
     def mock_tmux_cmd(*args: t.Any, **kwargs: t.Any) -> Hi:
@@ -62,12 +62,12 @@ def mock_tmux_cmd(*args: t.Any, **kwargs: t.Any) -> Hi:
     assert has_minimum_version()
     assert has_gte_version(TMUX_MIN_VERSION)
     assert has_gt_version(TMUX_MAX_VERSION), "Greater than the max-supported version"
-    assert TMUX_NEXT_VERSION == get_version()
+    assert get_version() == TMUX_NEXT_VERSION
 
 
 def test_get_version_openbsd(monkeypatch: pytest.MonkeyPatch) -> None:
     class Hi:
-        stderr = ["tmux: unknown option -- V"]
+        stderr: t.ClassVar = ["tmux: unknown option -- V"]
 
     def mock_tmux_cmd(*args: t.Any, **kwargs: t.Any) -> Hi:
         return Hi()
@@ -84,7 +84,7 @@ def mock_tmux_cmd(*args: t.Any, **kwargs: t.Any) -> Hi:
 
 def test_get_version_too_low(monkeypatch: pytest.MonkeyPatch) -> None:
     class Hi:
-        stderr = ["tmux: unknown option -- V"]
+        stderr: t.ClassVar = ["tmux: unknown option -- V"]
 
     def mock_tmux_cmd(*args: t.Any, **kwargs: t.Any) -> Hi:
         return Hi()
@@ -184,10 +184,10 @@ def test_tmux_cmd_unicode(session: Session) -> None:
 @pytest.mark.parametrize(
     "session_name,raises,exc_msg_regex",
     [
-        ("", True, "may not be empty"),
-        (None, True, "may not be empty"),
-        ("my great session.", True, "may not contain periods"),
-        ("name: great session", True, "may not contain colons"),
+        ("", True, "empty"),
+        (None, True, "empty"),
+        ("my great session.", True, "contains periods"),
+        ("name: great session", True, "contains colons"),
         ("new great session", False, None),
         ("ajf8a3fa83fads,,,a", False, None),
     ],
diff --git a/tests/legacy_api/test_server.py b/tests/legacy_api/test_server.py
index d7830fd0b..af815edb1 100644
--- a/tests/legacy_api/test_server.py
+++ b/tests/legacy_api/test_server.py
@@ -1,5 +1,6 @@
 """Test for libtmux Server object."""
 import logging
+import subprocess
 
 import pytest
 
@@ -71,12 +72,12 @@ def test_show_environment(server: Server) -> None:
 def test_getenv(server: Server, session: Session) -> None:
     """Set environment then Server.show_environment(key)."""
     server.set_environment("FOO", "BAR")
-    assert "BAR" == server.getenv("FOO")
+    assert server.getenv("FOO") == "BAR"
 
     server.set_environment("FOO", "DAR")
-    assert "DAR" == server.getenv("FOO")
+    assert server.getenv("FOO") == "DAR"
 
-    assert "DAR" == server.show_environment()["FOO"]
+    assert server.show_environment()["FOO"] == "DAR"
 
 
 def test_show_environment_not_set(server: Server) -> None:
@@ -149,7 +150,7 @@ def test_with_server_is_alive(server: Server) -> None:
 
 def test_no_server_raise_if_dead() -> None:
     dead_server = Server(socket_name="test_attached_session_no_server")
-    with pytest.raises(Exception):
+    with pytest.raises(subprocess.SubprocessError):
         dead_server.raise_if_dead()
 
 
diff --git a/tests/test_common.py b/tests/test_common.py
index f5bdccb04..5a1407c86 100644
--- a/tests/test_common.py
+++ b/tests/test_common.py
@@ -30,7 +30,7 @@
 
 def test_allows_master_version(monkeypatch: pytest.MonkeyPatch) -> None:
     class Hi:
-        stdout = ["tmux master"]
+        stdout: t.ClassVar = ["tmux master"]
         stderr = None
 
     def mock_tmux_cmd(*args: t.Any, **kwargs: t.Any) -> Hi:
@@ -50,7 +50,7 @@ def test_allows_next_version(monkeypatch: pytest.MonkeyPatch) -> None:
     TMUX_NEXT_VERSION = str(float(TMUX_MAX_VERSION) + 0.1)
 
     class Hi:
-        stdout = [f"tmux next-{TMUX_NEXT_VERSION}"]
+        stdout: t.ClassVar = [f"tmux next-{TMUX_NEXT_VERSION}"]
         stderr = None
 
     def mock_tmux_cmd(*args: t.Any, **kwargs: t.Any) -> Hi:
@@ -61,12 +61,12 @@ def mock_tmux_cmd(*args: t.Any, **kwargs: t.Any) -> Hi:
     assert has_minimum_version()
     assert has_gte_version(TMUX_MIN_VERSION)
     assert has_gt_version(TMUX_MAX_VERSION), "Greater than the max-supported version"
-    assert TMUX_NEXT_VERSION == get_version()
+    assert get_version() == TMUX_NEXT_VERSION
 
 
 def test_get_version_openbsd(monkeypatch: pytest.MonkeyPatch) -> None:
     class Hi:
-        stderr = ["tmux: unknown option -- V"]
+        stderr: t.ClassVar = ["tmux: unknown option -- V"]
 
     def mock_tmux_cmd(*args: t.Any, **kwargs: t.Any) -> Hi:
         return Hi()
@@ -83,7 +83,7 @@ def mock_tmux_cmd(*args: t.Any, **kwargs: t.Any) -> Hi:
 
 def test_get_version_too_low(monkeypatch: pytest.MonkeyPatch) -> None:
     class Hi:
-        stderr = ["tmux: unknown option -- V"]
+        stderr: t.ClassVar = ["tmux: unknown option -- V"]
 
     def mock_tmux_cmd(*args: t.Any, **kwargs: t.Any) -> Hi:
         return Hi()
@@ -189,10 +189,10 @@ class SessionCheckName(t.NamedTuple):
 @pytest.mark.parametrize(
     SessionCheckName._fields,
     [
-        SessionCheckName("", True, "may not be empty"),
-        SessionCheckName(None, True, "may not be empty"),
-        SessionCheckName("my great session.", True, "may not contain periods"),
-        SessionCheckName("name: great session", True, "may not contain colons"),
+        SessionCheckName("", True, "empty"),
+        SessionCheckName(None, True, "empty"),
+        SessionCheckName("my great session.", True, "contains periods"),
+        SessionCheckName("name: great session", True, "contains colons"),
         SessionCheckName("new great session", False, None),
         SessionCheckName("ajf8a3fa83fads,,,a", False, None),
     ],
diff --git a/tests/test_pytest_plugin.py b/tests/test_pytest_plugin.py
index 531932aa8..9dbf994e5 100644
--- a/tests/test_pytest_plugin.py
+++ b/tests/test_pytest_plugin.py
@@ -50,10 +50,9 @@ def test_repo_git_remote_checkout(
         """
         )
     }
-    first_test_key = list(files.keys())[0]
+    first_test_key = next(iter(files.keys()))
     first_test_filename = str(tests_path / first_test_key)
 
-    # Setup: Files
     tests_path.mkdir()
     for file_name, text in files.items():
         test_file = tests_path / file_name
diff --git a/tests/test_server.py b/tests/test_server.py
index 711964e27..183ceede4 100644
--- a/tests/test_server.py
+++ b/tests/test_server.py
@@ -1,5 +1,6 @@
 """Test for libtmux Server object."""
 import logging
+import subprocess
 
 import pytest
 
@@ -71,12 +72,12 @@ def test_show_environment(server: Server) -> None:
 def test_getenv(server: Server, session: Session) -> None:
     """Set environment then Server.show_environment(key)."""
     server.set_environment("FOO", "BAR")
-    assert "BAR" == server.getenv("FOO")
+    assert server.getenv("FOO") == "BAR"
 
     server.set_environment("FOO", "DAR")
-    assert "DAR" == server.getenv("FOO")
+    assert server.getenv("FOO") == "DAR"
 
-    assert "DAR" == server.show_environment()["FOO"]
+    assert server.show_environment()["FOO"] == "DAR"
 
 
 def test_show_environment_not_set(server: Server) -> None:
@@ -166,7 +167,7 @@ def test_with_server_is_alive(server: Server) -> None:
 
 def test_no_server_raise_if_dead() -> None:
     dead_server = Server(socket_name="test_attached_session_no_server")
-    with pytest.raises(Exception):
+    with pytest.raises(subprocess.CalledProcessError):
         dead_server.raise_if_dead()
 
 
diff --git a/tests/test_window.py b/tests/test_window.py
index aa9a1cd6a..94e20b480 100644
--- a/tests/test_window.py
+++ b/tests/test_window.py
@@ -203,7 +203,7 @@ def test_kill_window(session: Session) -> None:
 
     w = session.attached_window
 
-    w.window_id
+    assert w.window_id is not None
 
     w.kill_window()
     with pytest.raises(ObjectDoesNotExist):