CLN: replace Dict with Mapping to annotate arguments (#29155)

Author: simonjayhawkins

pandas/_typing.py

@@ -1,5 +1,15 @@
 from pathlib import Path
-from typing import IO, TYPE_CHECKING, AnyStr, Iterable, Optional, TypeVar, Union
+from typing import (
+    IO,
+    TYPE_CHECKING,
+    AnyStr,
+    Dict,
+    Iterable,
+    List,
+    Optional,
+    TypeVar,
+    Union,
+)
 
 import numpy as np
 
@@ -25,6 +35,7 @@
 Scalar = Union[str, int, float, bool]
 Axis = Union[str, int]
 Ordered = Optional[bool]
+JSONSerializable = Union[Scalar, List, Dict]
 
 # use Collection after we drop support for py35
 Axes = Iterable

pandas/core/dtypes/dtypes.py

@@ -1,6 +1,6 @@
 """ define extension dtypes """
 import re
-from typing import Any, Dict, List, Optional, Tuple, Type, Union, cast
+from typing import Any, Dict, List, MutableMapping, Optional, Tuple, Type, Union, cast
 import warnings
 
 import numpy as np
@@ -351,7 +351,7 @@ def _finalize(self, categories, ordered: Ordered, fastpath: bool = False) -> Non
         self._ordered = ordered if ordered is not ordered_sentinel else None
         self._ordered_from_sentinel = ordered is ordered_sentinel
 
-    def __setstate__(self, state: Dict[str_type, Any]) -> None:
+    def __setstate__(self, state: MutableMapping[str_type, Any]) -> None:
         # for pickle compat. __get_state__ is defined in the
         # PandasExtensionDtype superclass and uses the public properties to
         # pickle -> need to set the settable private ones here (see GH26067)

pandas/core/generic.py

@@ -67,7 +67,7 @@
 from pandas.core.dtypes.missing import isna, notna
 
 import pandas as pd
-from pandas._typing import Dtype, FilePathOrBuffer, Scalar
+from pandas._typing import Dtype, FilePathOrBuffer, JSONSerializable
 from pandas.core import missing, nanops
 import pandas.core.algorithms as algos
 from pandas.core.base import PandasObject, SelectionMixin
@@ -2299,7 +2299,7 @@ def to_json(
         double_precision: int = 10,
         force_ascii: bool_t = True,
         date_unit: str = "ms",
-        default_handler: Optional[Callable[[Any], Union[Scalar, List, Dict]]] = None,
+        default_handler: Optional[Callable[[Any], JSONSerializable]] = None,
         lines: bool_t = False,
         compression: Optional[str] = "infer",
         index: bool_t = True,
@@ -3155,7 +3155,7 @@ def to_csv(
         index_label: Optional[Union[bool_t, str, Sequence[Hashable]]] = None,
         mode: str = "w",
         encoding: Optional[str] = None,
-        compression: Optional[Union[str, Dict[str, str]]] = "infer",
+        compression: Optional[Union[str, Mapping[str, str]]] = "infer",
         quoting: Optional[int] = None,
         quotechar: str = '"',
         line_terminator: Optional[str] = None,

pandas/core/ops/array_ops.py

@@ -3,7 +3,7 @@
 ExtensionArrays.
 """
 import operator
-from typing import Any, Dict, Union
+from typing import Any, Mapping, Union
 
 import numpy as np
 
@@ -161,7 +161,7 @@ def arithmetic_op(
     right: Any,
     op,
     str_rep: str,
-    eval_kwargs: Dict[str, bool],
+    eval_kwargs: Mapping[str, bool],
 ):
     """
     Evaluate an arithmetic operation `+`, `-`, `*`, `/`, `//`, `%`, `**`, ...

pandas/io/common.py

@@ -15,6 +15,7 @@
     BinaryIO,
     Dict,
     List,
+    Mapping,
     Optional,
     TextIO,
     Tuple,
@@ -276,16 +277,16 @@ def file_path_to_url(path: str) -> str:
 
 
 def _get_compression_method(
-    compression: Optional[Union[str, Dict[str, str]]]
+    compression: Optional[Union[str, Mapping[str, str]]]
 ) -> Tuple[Optional[str], Dict[str, str]]:
     """
     Simplifies a compression argument to a compression method string and
-    a dict containing additional arguments.
+    a mapping containing additional arguments.
 
     Parameters
     ----------
-    compression : str or dict
-        If string, specifies the compression method. If dict, value at key
+    compression : str or mapping
+        If string, specifies the compression method. If mapping, value at key
         'method' specifies compression method.
 
     Returns
@@ -295,15 +296,14 @@ def _get_compression_method(
 
     Raises
     ------
-    ValueError on dict missing 'method' key
+    ValueError on mapping missing 'method' key
     """
-    # Handle dict
-    if isinstance(compression, dict):
-        compression_args = compression.copy()
+    if isinstance(compression, Mapping):
+        compression_args = dict(compression)
         try:
             compression = compression_args.pop("method")
         except KeyError:
-            raise ValueError("If dict, compression must have key 'method'")
+            raise ValueError("If mapping, compression must have key 'method'")
     else:
         compression_args = {}
     return compression, compression_args
@@ -368,7 +368,7 @@ def _get_handle(
     path_or_buf,
     mode: str,
     encoding=None,
-    compression: Optional[Union[str, Dict[str, Any]]] = None,
+    compression: Optional[Union[str, Mapping[str, Any]]] = None,
     memory_map: bool = False,
     is_text: bool = True,
 ):

pandas/io/formats/format.py

@@ -20,6 +20,7 @@
     Dict,
     Iterable,
     List,
+    Mapping,
     Optional,
     Sequence,
     Tuple,
@@ -78,7 +79,7 @@
     from pandas import Series, DataFrame, Categorical
 
 formatters_type = Union[
-    List[Callable], Tuple[Callable, ...], Dict[Union[str, int], Callable]
+    List[Callable], Tuple[Callable, ...], Mapping[Union[str, int], Callable]
 ]
 float_format_type = Union[str, Callable, "EngFormatter"]
 

pandas/io/formats/html.py

@@ -4,7 +4,7 @@
 
 from collections import OrderedDict
 from textwrap import dedent
-from typing import IO, Any, Dict, Iterable, List, Optional, Tuple, Union, cast
+from typing import IO, Any, Dict, Iterable, List, Mapping, Optional, Tuple, Union, cast
 
 from pandas._config import get_option
 
@@ -394,7 +394,7 @@ def _write_body(self, indent: int) -> None:
         self.write("</tbody>", indent)
 
     def _write_regular_rows(
-        self, fmt_values: Dict[int, List[str]], indent: int
+        self, fmt_values: Mapping[int, List[str]], indent: int
     ) -> None:
         truncate_h = self.fmt.truncate_h
         truncate_v = self.fmt.truncate_v
@@ -440,7 +440,7 @@ def _write_regular_rows(
             )
 
     def _write_hierarchical_rows(
-        self, fmt_values: Dict[int, List[str]], indent: int
+        self, fmt_values: Mapping[int, List[str]], indent: int
     ) -> None:
         template = 'rowspan="{span}" valign="top"'
 

pandas/io/formats/printing.py

@@ -3,13 +3,23 @@
 """
 
 import sys
-from typing import Any, Callable, Dict, Iterable, List, Optional, Sequence, Tuple, Union
+from typing import (
+    Any,
+    Callable,
+    Iterable,
+    List,
+    Mapping,
+    Optional,
+    Sequence,
+    Tuple,
+    Union,
+)
 
 from pandas._config import get_option
 
 from pandas.core.dtypes.inference import is_sequence
 
-EscapeChars = Union[Dict[str, str], Iterable[str]]
+EscapeChars = Union[Mapping[str, str], Iterable[str]]
 
 
 def adjoin(space: int, *lists: List[str], **kwargs) -> str:
@@ -119,7 +129,7 @@ def _pprint_seq(
 
 
 def _pprint_dict(
-    seq: Dict, _nest_lvl: int = 0, max_seq_items: Optional[int] = None, **kwds
+    seq: Mapping, _nest_lvl: int = 0, max_seq_items: Optional[int] = None, **kwds
 ) -> str:
     """
     internal. pprinter for iterables. you should probably use pprint_thing()

pandas/io/json/_json.py

@@ -2,7 +2,7 @@
 from io import StringIO
 from itertools import islice
 import os
-from typing import Any, Callable, Dict, List, Optional, Type, Union
+from typing import Any, Callable, Optional, Type
 
 import numpy as np
 
@@ -13,7 +13,7 @@
 from pandas.core.dtypes.common import ensure_str, is_period_dtype
 
 from pandas import DataFrame, MultiIndex, Series, compat, isna, to_datetime
-from pandas._typing import Scalar
+from pandas._typing import JSONSerializable
 from pandas.core.reshape.concat import concat
 
 from pandas.io.common import (
@@ -34,8 +34,6 @@
 
 TABLE_SCHEMA_VERSION = "0.20.0"
 
-Serializable = Union[Scalar, List, Dict]
-
 
 # interface to/from
 def to_json(
@@ -46,7 +44,7 @@ def to_json(
     double_precision: int = 10,
     force_ascii: bool = True,
     date_unit: str = "ms",
-    default_handler: Optional[Callable[[Any], Serializable]] = None,
+    default_handler: Optional[Callable[[Any], JSONSerializable]] = None,
     lines: bool = False,
     compression: Optional[str] = "infer",
     index: bool = True,
@@ -110,7 +108,7 @@ def __init__(
         ensure_ascii: bool,
         date_unit: str,
         index: bool,
-        default_handler: Optional[Callable[[Any], Serializable]] = None,
+        default_handler: Optional[Callable[[Any], JSONSerializable]] = None,
         indent: int = 0,
     ):
         self.obj = obj
@@ -153,7 +151,7 @@ def _write(
         ensure_ascii: bool,
         date_unit: str,
         iso_dates: bool,
-        default_handler: Optional[Callable[[Any], Serializable]],
+        default_handler: Optional[Callable[[Any], JSONSerializable]],
         indent: int,
     ):
         return dumps(
@@ -186,7 +184,7 @@ def _write(
         ensure_ascii: bool,
         date_unit: str,
         iso_dates: bool,
-        default_handler: Optional[Callable[[Any], Serializable]],
+        default_handler: Optional[Callable[[Any], JSONSerializable]],
         indent: int,
     ):
         if not self.index and orient == "split":
@@ -233,7 +231,7 @@ def _write(
         ensure_ascii: bool,
         date_unit: str,
         iso_dates: bool,
-        default_handler: Optional[Callable[[Any], Serializable]],
+        default_handler: Optional[Callable[[Any], JSONSerializable]],
         indent: int,
     ):
         if not self.index and orient == "split":
@@ -263,7 +261,7 @@ def __init__(
         ensure_ascii: bool,
         date_unit: str,
         index: bool,
-        default_handler: Optional[Callable[[Any], Serializable]] = None,
+        default_handler: Optional[Callable[[Any], JSONSerializable]] = None,
         indent: int = 0,
     ):
         """

pandas/util/_decorators.py

@@ -4,8 +4,8 @@
 from typing import (
     Any,
     Callable,
-    Dict,
     List,
+    Mapping,
     Optional,
     Tuple,
     Type,
@@ -104,7 +104,7 @@ def wrapper(*args, **kwargs) -> Callable[..., Any]:
 def deprecate_kwarg(
     old_arg_name: str,
     new_arg_name: Optional[str],
-    mapping: Optional[Union[Dict[Any, Any], Callable[[Any], Any]]] = None,
+    mapping: Optional[Union[Mapping[Any, Any], Callable[[Any], Any]]] = None,
     stacklevel: int = 2,
 ) -> Callable[..., Any]:
     """