Activate pylint convention rules in ruff (streamlit#8874)

## Describe your changes

This PR activates the pylint convention rules in ruff + updates ruff to
0.5.

## Testing Plan

- No logical changes -> no tests required

---

**Contribution License Agreement**

By submitting this pull request you agree that all contributions to this
project are made under the Apache 2.0 license.

.ruff.toml

@@ -34,6 +34,7 @@ select = [
   "ISC",    # Encourage correct string literal concatenation.
   "LOG",    # Checks for issues using the standard library logging module.
   "NPY",    # Linting rules for numpy
+  "PLC",    # pycodestyle conventions
   "PYI",    # Linting rules for type annotations.
   "Q",      # Linting rules for quites
   "RUF100", # Unused noqa directive
@@ -44,15 +45,16 @@ select = [
   "W",      # pycodestyle warnings
 ]
 ignore = [
-  "B008",   # Checks for function calls in default function arguments.
-  "B904",   # Checks for raise statements in exception handlers that lack a from clause.
-  "E501",   # Checks for lines that exceed the specified maximum character length.
-  "ISC001", # Checks for implicitly concatenated strings on a single line.
-  "NPY002", # Checks for the use of legacy np.random function calls.
-  "PYI036", # Checks for incorrect function signatures on __exit__ and __aexit__ methods.
-  "PYI041", # Checks for parameter annotations that contain redundant unions between builtin numeric types (e.g., int | float).
-  "PYI051", # Checks for redundant unions between a Literal and a builtin supertype of that Literal.
-  "UP031",  # Checks for printf-style string formatting, and offers to replace it with str.format calls.
+  "B008",    # Checks for function calls in default function arguments.
+  "B904",    # Checks for raise statements in exception handlers that lack a from clause.
+  "E501",    # Checks for lines that exceed the specified maximum character length.
+  "ISC001",  # Checks for implicitly concatenated strings on a single line.
+  "NPY002",  # Checks for the use of legacy np.random function calls.
+  "PYI036",  # Checks for incorrect function signatures on __exit__ and __aexit__ methods.
+  "PYI041",  # Checks for parameter annotations that contain redundant unions between builtin numeric types (e.g., int | float).
+  "PYI051",  # Checks for redundant unions between a Literal and a builtin supertype of that Literal.
+  "UP031",   # Checks for printf-style string formatting, and offers to replace it with str.format calls.
+  "PLC0208", # Checks for iterations over set literals.
 ]
 # Do not lint files in tests, scripts, and vendor directory:
 exclude = [
@@ -64,7 +66,7 @@ exclude = [
 
 [lint.per-file-ignores]
 "e2e_playwright/**" = ["T20", "B018"]
-"lib/streamlit/__init__.py" = ["E402"]
+"lib/streamlit/__init__.py" = ["E402", "PLC0414"]
 
 [lint.flake8-tidy-imports]
 # Disallow all relative imports.

e2e_playwright/st_graphviz_chart.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import graphviz as graphviz
+import graphviz
 
 import streamlit as st
 

lib/dev-requirements.txt

@@ -1,6 +1,6 @@
 pre-commit
 # We fix ruff to a version to be in sync with the pre-commit hook:
-ruff==0.4.8
+ruff==0.5
 mypy>=1.4, <1.7
 mypy-protobuf>=3.2
 # semver 3 renames VersionInfo so temporarily pin until we deal with it

lib/streamlit/components/v1/components.py

@@ -20,6 +20,6 @@
 # model the old behavior and not to break things.
 
 from streamlit.components.v1.component_registry import (
-    declare_component as declare_component,
+    declare_component as declare_component,  # noqa: PLC0414
 )
 from streamlit.components.v1.custom_component import *  # noqa: F403

lib/streamlit/testing/v1/element_tree.py

@@ -201,12 +201,12 @@ def set_value(self, v: Any):
     def _widget_state(self) -> WidgetState: ...
 
 
-El = TypeVar("El", bound=Element, covariant=True)
+El_co = TypeVar("El_co", bound=Element, covariant=True)
 
 
-class ElementList(Generic[El]):
-    def __init__(self, els: Sequence[El]):
-        self._list: Sequence[El] = els
+class ElementList(Generic[El_co]):
+    def __init__(self, els: Sequence[El_co]):
+        self._list: Sequence[El_co] = els
 
     def __len__(self) -> int:
         return len(self._list)
@@ -216,12 +216,12 @@ def len(self) -> int:
         return len(self)
 
     @overload
-    def __getitem__(self, idx: int) -> El: ...
+    def __getitem__(self, idx: int) -> El_co: ...
 
     @overload
-    def __getitem__(self, idx: slice) -> ElementList[El]: ...
+    def __getitem__(self, idx: slice) -> ElementList[El_co]: ...
 
-    def __getitem__(self, idx: int | slice) -> El | ElementList[El]:
+    def __getitem__(self, idx: int | slice) -> El_co | ElementList[El_co]:
         if isinstance(idx, slice):
             return ElementList(self._list[idx])
         else:
@@ -233,7 +233,7 @@ def __iter__(self):
     def __repr__(self):
         return util.repr_(self)
 
-    def __eq__(self, other: ElementList[El] | object) -> bool:
+    def __eq__(self, other: ElementList[El_co] | object) -> bool:
         if isinstance(other, ElementList):
             return self._list == other._list
         else:
@@ -244,11 +244,11 @@ def values(self) -> Sequence[Any]:
         return [e.value for e in self]
 
 
-W = TypeVar("W", bound=Widget, covariant=True)
+W_co = TypeVar("W_co", bound=Widget, covariant=True)
 
 
-class WidgetList(ElementList[W], Generic[W]):
-    def __call__(self, key: str) -> W:
+class WidgetList(ElementList[W_co], Generic[W_co]):
+    def __call__(self, key: str) -> W_co:
         for e in self._list:
             if e.key == key:
                 return e