TYP: annotation of __init__ return type (PEP 484) (pandas/io)

pandas/io/clipboard/__init__.py

@@ -93,7 +93,7 @@ class PyperclipException(RuntimeError):
 
 
 class PyperclipWindowsException(PyperclipException):
-    def __init__(self, message):
+    def __init__(self, message) -> None:
         message += f" ({ctypes.WinError()})"
         super().__init__(message)
 
@@ -305,7 +305,7 @@ def __bool__(self) -> bool:
 
 # Windows-related clipboard functions:
 class CheckedCall:
-    def __init__(self, f):
+    def __init__(self, f) -> None:
         super().__setattr__("f", f)
 
     def __call__(self, *args):

pandas/io/common.py

@@ -872,7 +872,7 @@ def __init__(
         mode: str,
         archive_name: str | None = None,
         **kwargs,
-    ):
+    ) -> None:
         mode = mode.replace("b", "")
         self.archive_name = archive_name
         self.multiple_write_buffer: StringIO | BytesIO | None = None
@@ -944,7 +944,7 @@ def __init__(
         encoding: str = "utf-8",
         errors: str = "strict",
         decode: bool = True,
-    ):
+    ) -> None:
         self.encoding = encoding
         self.errors = errors
         self.decoder = codecs.getincrementaldecoder(encoding)(errors=errors)
@@ -999,7 +999,7 @@ class _IOWrapper:
     # methods, e.g., tempfile.SpooledTemporaryFile.
     # If a buffer does not have the above "-able" methods, we simple assume they are
     # seek/read/writ-able.
-    def __init__(self, buffer: BaseBuffer):
+    def __init__(self, buffer: BaseBuffer) -> None:
         self.buffer = buffer
 
     def __getattr__(self, name: str):
@@ -1026,7 +1026,7 @@ def writable(self) -> bool:
 class _BytesIOWrapper:
     # Wrapper that wraps a StringIO buffer and reads bytes from it
     # Created for compat with pyarrow read_csv
-    def __init__(self, buffer: StringIO | TextIOBase, encoding: str = "utf-8"):
+    def __init__(self, buffer: StringIO | TextIOBase, encoding: str = "utf-8") -> None:
         self.buffer = buffer
         self.encoding = encoding
         # Because a character can be represented by more than 1 byte,

pandas/io/excel/_base.py

@@ -497,7 +497,9 @@ def read_excel(
 
 
 class BaseExcelReader(metaclass=abc.ABCMeta):
-    def __init__(self, filepath_or_buffer, storage_options: StorageOptions = None):
+    def __init__(
+        self, filepath_or_buffer, storage_options: StorageOptions = None
+    ) -> None:
         # First argument can also be bytes, so create a buffer
         if isinstance(filepath_or_buffer, bytes):
             filepath_or_buffer = BytesIO(filepath_or_buffer)
@@ -1131,7 +1133,7 @@ def __init__(
         if_sheet_exists: str | None = None,
         engine_kwargs: dict[str, Any] | None = None,
         **kwargs,
-    ):
+    ) -> None:
         # validate that this engine can handle the extension
         if isinstance(path, str):
             ext = os.path.splitext(path)[-1]
@@ -1454,7 +1456,7 @@ def __init__(
         path_or_buffer,
         engine: str | None = None,
         storage_options: StorageOptions = None,
-    ):
+    ) -> None:
         if engine is not None and engine not in self._engines:
             raise ValueError(f"Unknown engine: {engine}")
 

pandas/io/excel/_odfreader.py

@@ -41,7 +41,7 @@ def __init__(
         self,
         filepath_or_buffer: FilePath | ReadBuffer[bytes],
         storage_options: StorageOptions = None,
-    ):
+    ) -> None:
         import_optional_dependency("odf")
         super().__init__(filepath_or_buffer, storage_options=storage_options)
 

pandas/io/excel/_odswriter.py

@@ -39,7 +39,7 @@ def __init__(
         if_sheet_exists: str | None = None,
         engine_kwargs: dict[str, Any] | None = None,
         **kwargs,
-    ):
+    ) -> None:
         from odf.opendocument import OpenDocumentSpreadsheet
 
         if mode == "a":

pandas/io/excel/_openpyxl.py

@@ -50,7 +50,7 @@ def __init__(
         if_sheet_exists: str | None = None,
         engine_kwargs: dict[str, Any] | None = None,
         **kwargs,
-    ):
+    ) -> None:
         # Use the openpyxl module as the Excel writer.
         from openpyxl.workbook import Workbook
 

pandas/io/excel/_pyxlsb.py

@@ -21,7 +21,7 @@ def __init__(
         self,
         filepath_or_buffer: FilePath | ReadBuffer[bytes],
         storage_options: StorageOptions = None,
-    ):
+    ) -> None:
         """
         Reader using pyxlsb engine.
 

pandas/io/excel/_xlrd.py

@@ -13,7 +13,9 @@
 
 class XlrdReader(BaseExcelReader):
     @doc(storage_options=_shared_docs["storage_options"])
-    def __init__(self, filepath_or_buffer, storage_options: StorageOptions = None):
+    def __init__(
+        self, filepath_or_buffer, storage_options: StorageOptions = None
+    ) -> None:
         """
         Reader using xlrd engine.
 

pandas/io/excel/_xlsxwriter.py

@@ -183,7 +183,7 @@ def __init__(
         if_sheet_exists: str | None = None,
         engine_kwargs: dict[str, Any] | None = None,
         **kwargs,
-    ):
+    ) -> None:
         # Use the xlsxwriter module as the Excel writer.
         from xlsxwriter import Workbook
 

pandas/io/excel/_xlwt.py

@@ -40,7 +40,7 @@ def __init__(
         if_sheet_exists: str | None = None,
         engine_kwargs: dict[str, Any] | None = None,
         **kwargs,
-    ):
+    ) -> None:
         # Use the xlwt module as the Excel writer.
         import xlwt
 

pandas/io/formats/csvs.py

@@ -66,7 +66,7 @@ def __init__(
         doublequote: bool = True,
         escapechar: str | None = None,
         storage_options: StorageOptions = None,
-    ):
+    ) -> None:
         self.fmt = formatter
 
         self.obj = self.fmt.frame

pandas/io/formats/excel.py

@@ -62,7 +62,7 @@ def __init__(
         style=None,
         mergestart: int | None = None,
         mergeend: int | None = None,
-    ):
+    ) -> None:
         self.row = row
         self.col = col
         self.val = val
@@ -83,7 +83,7 @@ def __init__(
         css_col: int,
         css_converter: Callable | None,
         **kwargs,
-    ):
+    ) -> None:
         if css_styles and css_converter:
             css = ";".join(
                 [a + ":" + str(v) for (a, v) in css_styles[css_row, css_col]]
@@ -158,7 +158,7 @@ class CSSToExcelConverter:
     #     without monkey-patching.
     inherited: dict[str, str] | None
 
-    def __init__(self, inherited: str | None = None):
+    def __init__(self, inherited: str | None = None) -> None:
         if inherited is not None:
             self.inherited = self.compute_css(inherited)
         else:
@@ -493,7 +493,7 @@ def __init__(
         merge_cells: bool = False,
         inf_rep: str = "inf",
         style_converter: Callable | None = None,
-    ):
+    ) -> None:
         self.rowcounter = 0
         self.na_rep = na_rep
         if not isinstance(df, DataFrame):

pandas/io/formats/format.py

@@ -204,7 +204,7 @@ def __init__(
         length: bool = True,
         na_rep: str = "NaN",
         footer: bool = True,
-    ):
+    ) -> None:
         self.categorical = categorical
         self.buf = buf if buf is not None else StringIO("")
         self.na_rep = na_rep
@@ -274,7 +274,7 @@ def __init__(
         dtype: bool = True,
         max_rows: int | None = None,
         min_rows: int | None = None,
-    ):
+    ) -> None:
         self.series = series
         self.buf = buf if buf is not None else StringIO()
         self.name = name
@@ -421,7 +421,7 @@ def to_string(self) -> str:
 
 
 class TextAdjustment:
-    def __init__(self):
+    def __init__(self) -> None:
         self.encoding = get_option("display.encoding")
 
     def len(self, text: str) -> int:
@@ -435,7 +435,7 @@ def adjoin(self, space: int, *lists, **kwargs) -> str:
 
 
 class EastAsianTextAdjustment(TextAdjustment):
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__()
         if get_option("display.unicode.ambiguous_as_wide"):
             self.ambiguous_width = 2
@@ -578,7 +578,7 @@ def __init__(
         decimal: str = ".",
         bold_rows: bool = False,
         escape: bool = True,
-    ):
+    ) -> None:
         self.frame = frame
         self.columns = self._initialize_columns(columns)
         self.col_space = self._initialize_colspace(col_space)
@@ -1017,7 +1017,7 @@ class DataFrameRenderer:
         Formatter with the formatting options.
     """
 
-    def __init__(self, fmt: DataFrameFormatter):
+    def __init__(self, fmt: DataFrameFormatter) -> None:
         self.fmt = fmt
 
     def to_latex(
@@ -1332,7 +1332,7 @@ def __init__(
         quoting: int | None = None,
         fixed_width: bool = True,
         leading_space: bool | None = True,
-    ):
+    ) -> None:
         self.values = values
         self.digits = digits
         self.na_rep = na_rep
@@ -1425,7 +1425,7 @@ def _format(x):
 
 
 class FloatArrayFormatter(GenericArrayFormatter):
-    def __init__(self, *args, **kwargs):
+    def __init__(self, *args, **kwargs) -> None:
         super().__init__(*args, **kwargs)
 
         # float_format is expected to be a string
@@ -1614,7 +1614,7 @@ def __init__(
         nat_rep: str = "NaT",
         date_format: None = None,
         **kwargs,
-    ):
+    ) -> None:
         super().__init__(values, **kwargs)
         self.nat_rep = nat_rep
         self.date_format = date_format
@@ -1823,7 +1823,7 @@ def __init__(
         nat_rep: str = "NaT",
         box: bool = False,
         **kwargs,
-    ):
+    ) -> None:
         super().__init__(values, **kwargs)
         self.nat_rep = nat_rep
         self.box = box
@@ -2023,7 +2023,9 @@ class EngFormatter:
         24: "Y",
     }
 
-    def __init__(self, accuracy: int | None = None, use_eng_prefix: bool = False):
+    def __init__(
+        self, accuracy: int | None = None, use_eng_prefix: bool = False
+    ) -> None:
         self.accuracy = accuracy
         self.use_eng_prefix = use_eng_prefix
 

pandas/io/formats/info.py

@@ -459,7 +459,7 @@ def __init__(
         self,
         data: DataFrame,
         memory_usage: bool | str | None = None,
-    ):
+    ) -> None:
         self.data: DataFrame = data
         self.memory_usage = _initialize_memory_usage(memory_usage)
 
@@ -535,7 +535,7 @@ def __init__(
         self,
         data: Series,
         memory_usage: bool | str | None = None,
-    ):
+    ) -> None:
         self.data: Series = data
         self.memory_usage = _initialize_memory_usage(memory_usage)
 
@@ -629,7 +629,7 @@ def __init__(
         max_cols: int | None = None,
         verbose: bool | None = None,
         show_counts: bool | None = None,
-    ):
+    ) -> None:
         self.info = info
         self.data = info.data
         self.verbose = verbose
@@ -706,7 +706,7 @@ def __init__(
         info: SeriesInfo,
         verbose: bool | None = None,
         show_counts: bool | None = None,
-    ):
+    ) -> None:
         self.info = info
         self.data = info.data
         self.verbose = verbose
@@ -797,7 +797,7 @@ class DataFrameTableBuilder(TableBuilderAbstract):
         Instance of DataFrameInfo.
     """
 
-    def __init__(self, *, info: DataFrameInfo):
+    def __init__(self, *, info: DataFrameInfo) -> None:
         self.info: DataFrameInfo = info
 
     def get_lines(self) -> list[str]:
@@ -959,7 +959,7 @@ def __init__(
         *,
         info: DataFrameInfo,
         with_counts: bool,
-    ):
+    ) -> None:
         self.info = info
         self.with_counts = with_counts
         self.strrows: Sequence[Sequence[str]] = list(self._gen_rows())
@@ -1025,7 +1025,7 @@ class SeriesTableBuilder(TableBuilderAbstract):
         Instance of SeriesInfo.
     """
 
-    def __init__(self, *, info: SeriesInfo):
+    def __init__(self, *, info: SeriesInfo) -> None:
         self.info: SeriesInfo = info
 
     def get_lines(self) -> list[str]:
@@ -1071,7 +1071,7 @@ def __init__(
         *,
         info: SeriesInfo,
         with_counts: bool,
-    ):
+    ) -> None:
         self.info = info
         self.with_counts = with_counts
         self.strrows: Sequence[Sequence[str]] = list(self._gen_rows())

pandas/io/formats/latex.py

@@ -74,7 +74,7 @@ def __init__(
         multicolumn: bool = False,
         multicolumn_format: str | None = None,
         multirow: bool = False,
-    ):
+    ) -> None:
         self.fmt = formatter
         self.frame = self.fmt.frame
         self.multicolumn = multicolumn
@@ -336,7 +336,7 @@ def __init__(
         short_caption: str | None = None,
         label: str | None = None,
         position: str | None = None,
-    ):
+    ) -> None:
         self.fmt = formatter
         self.column_format = column_format
         self.multicolumn = multicolumn
@@ -697,7 +697,7 @@ def __init__(
         caption: str | tuple[str, str] | None = None,
         label: str | None = None,
         position: str | None = None,
-    ):
+    ) -> None:
         self.fmt = formatter
         self.frame = self.fmt.frame
         self.longtable = longtable