Modern style type hints (#3863)

py-polars/polars/_html.py

@@ -1,19 +1,21 @@
 """
 Module for formatting output data in HTML.
 """
+from __future__ import annotations
+
 from textwrap import dedent
 from types import TracebackType
-from typing import Dict, Iterable, List, Optional, Type
+from typing import Iterable
 
 from polars.datatypes import Object
 
 
 class Tag:
     def __init__(
         self,
-        elements: List[str],
+        elements: list[str],
         tag: str,
-        attributes: Optional[Dict[str, str]] = None,
+        attributes: dict[str, str] | None = None,
     ):
         self.tag = tag
         self.elements = elements
@@ -31,17 +33,17 @@ def __enter__(self) -> None:
 
     def __exit__(
         self,
-        exc_type: Optional[Type[BaseException]],
-        exc_val: Optional[BaseException],
-        exc_tb: Optional[TracebackType],
+        exc_type: type[BaseException] | None,
+        exc_val: BaseException | None,
+        exc_tb: TracebackType | None,
     ) -> None:
         self.elements.append(f"</{self.tag}>")
 
 
 class HTMLFormatter:
-    def __init__(self, df: "DataFrame", max_cols: int = 75, max_rows: int = 40):  # type: ignore  # noqa
+    def __init__(self, df: DataFrame, max_cols: int = 75, max_rows: int = 40):  # type: ignore  # noqa
         self.df = df
-        self.elements: List[str] = []
+        self.elements: list[str] = []
         self.max_cols = max_cols
         self.max_rows = max_rows
         self.row_idx: Iterable[int]
@@ -109,7 +111,7 @@ def write_body(self) -> None:
     def write(self, inner: str) -> None:
         self.elements.append(inner)
 
-    def render(self) -> List[str]:
+    def render(self) -> list[str]:
         with Tag(self.elements, "table", {"border": "1", "class": "dataframe"}):
             self.write_header()
             self.write_body()
@@ -150,7 +152,7 @@ def write_style(self) -> None:
         template = dedent("\n".join((template_first, template_mid, template_last)))
         self.write(template)
 
-    def render(self) -> List[str]:
+    def render(self) -> list[str]:
         """
         Return the lines needed to render a HTML table.
         """

py-polars/polars/cfg.py

@@ -1,5 +1,6 @@
+from __future__ import annotations
+
 import os
-from typing import Type
 
 from polars.string_cache import toggle_string_cache
 
@@ -10,7 +11,7 @@ class Config:
     """
 
     @classmethod
-    def set_utf8_tables(cls) -> "Type[Config]":
+    def set_utf8_tables(cls) -> type[Config]:
         """
         Use utf8 characters to print tables
         """
@@ -21,15 +22,15 @@ def set_utf8_tables(cls) -> "Type[Config]":
         return cls
 
     @classmethod
-    def set_ascii_tables(cls) -> "Type[Config]":
+    def set_ascii_tables(cls) -> type[Config]:
         """
         Use ascii characters to print tables
         """
         os.environ["POLARS_FMT_NO_UTF8"] = "1"
         return cls
 
     @classmethod
-    def set_tbl_width_chars(cls, width: int) -> "Type[Config]":
+    def set_tbl_width_chars(cls, width: int) -> type[Config]:
         """
         Set the number of character used to draw the table
 
@@ -42,7 +43,7 @@ def set_tbl_width_chars(cls, width: int) -> "Type[Config]":
         return cls
 
     @classmethod
-    def set_tbl_rows(cls, n: int) -> "Type[Config]":
+    def set_tbl_rows(cls, n: int) -> type[Config]:
         """
         Set the number of rows used to print tables
 
@@ -56,7 +57,7 @@ def set_tbl_rows(cls, n: int) -> "Type[Config]":
         return cls
 
     @classmethod
-    def set_tbl_cols(cls, n: int) -> "Type[Config]":
+    def set_tbl_cols(cls, n: int) -> type[Config]:
         """
         Set the number of columns used to print tables
 
@@ -85,15 +86,15 @@ def set_tbl_cols(cls, n: int) -> "Type[Config]":
         return cls
 
     @classmethod
-    def set_global_string_cache(cls) -> "Type[Config]":
+    def set_global_string_cache(cls) -> type[Config]:
         """
         Turn on the global string cache
         """
         toggle_string_cache(True)
         return cls
 
     @classmethod
-    def unset_global_string_cache(cls) -> "Type[Config]":
+    def unset_global_string_cache(cls) -> type[Config]:
         """
         Turn off the global string cache
         """

py-polars/polars/convert.py

@@ -1,13 +1,6 @@
-from typing import (
-    TYPE_CHECKING,
-    Any,
-    Dict,
-    Mapping,
-    Optional,
-    Sequence,
-    Union,
-    overload,
-)
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Any, Mapping, Sequence, overload
 
 import numpy as np
 
@@ -28,8 +21,8 @@
 
 
 def from_dict(
-    data: Mapping[str, Union[Sequence, Mapping]],
-    columns: Optional[Sequence[str]] = None,
+    data: Mapping[str, Sequence | Mapping],
+    columns: Sequence[str] | None = None,
 ) -> DataFrame:
     """
     Construct a DataFrame from a dictionary of sequences.
@@ -69,9 +62,9 @@ def from_dict(
 
 
 def from_records(
-    data: Union[np.ndarray, Sequence[Sequence[Any]]],
-    columns: Optional[Sequence[str]] = None,
-    orient: Optional[str] = None,
+    data: np.ndarray | Sequence[Sequence[Any]],
+    columns: Sequence[str] | None = None,
+    orient: str | None = None,
 ) -> DataFrame:
     """
     Construct a DataFrame from a numpy ndarray or sequence of sequences.
@@ -118,8 +111,8 @@ def from_records(
 
 
 def from_dicts(
-    dicts: Sequence[Dict[str, Any]],
-    infer_schema_length: Optional[int] = 50,
+    dicts: Sequence[dict[str, Any]],
+    infer_schema_length: int | None = 50,
 ) -> DataFrame:
     """
     Construct a DataFrame from a sequence of dictionaries.
@@ -161,8 +154,8 @@ def from_dicts(
 
 # Note that we cannot overload because pyarrow has no stubs :(
 def from_arrow(
-    a: Union["pa.Table", "pa.Array", "pa.ChunkedArray"], rechunk: bool = True
-) -> Union[DataFrame, Series]:
+    a: pa.Table | pa.Array | pa.ChunkedArray, rechunk: bool = True
+) -> DataFrame | Series:
     """
     Create a DataFrame or Series from an Arrow Table or Array.
 
@@ -230,7 +223,7 @@ def from_arrow(
 
 @overload
 def from_pandas(
-    df: "pd.DataFrame",
+    df: pd.DataFrame,
     rechunk: bool = True,
     nan_to_none: bool = True,
 ) -> DataFrame:
@@ -239,18 +232,18 @@ def from_pandas(
 
 @overload
 def from_pandas(
-    df: Union["pd.Series", "pd.DatetimeIndex"],
+    df: pd.Series | pd.DatetimeIndex,
     rechunk: bool = True,
     nan_to_none: bool = True,
 ) -> Series:
     ...
 
 
 def from_pandas(
-    df: Union["pd.DataFrame", "pd.Series", "pd.DatetimeIndex"],
+    df: pd.DataFrame | pd.Series | pd.DatetimeIndex,
     rechunk: bool = True,
     nan_to_none: bool = True,
-) -> Union[DataFrame, Series]:
+) -> DataFrame | Series:
     """
     Construct a Polars DataFrame or Series from a pandas DataFrame or Series.