Sync Fork from Upstream Repo

doc/source/development/contributing.rst

@@ -32,7 +32,7 @@ check each issue individually, and it's not possible to find the unassigned ones
 
 For this reason, we implemented a workaround consisting of adding a comment with the exact
 text `take`. When you do it, a GitHub action will automatically assign you the issue
-(this will take seconds, and may require refreshint the page to see it).
+(this will take seconds, and may require refreshing the page to see it).
 By doing this, it's possible to filter the list of issues and find only the unassigned ones.
 
 So, a good way to find an issue to start contributing to pandas is to check the list of

doc/source/whatsnew/v1.1.0.rst

@@ -54,7 +54,7 @@ Other API changes
 
 - :meth:`Series.describe` will now show distribution percentiles for ``datetime`` dtypes, statistics ``first`` and ``last``
   will now be ``min`` and ``max`` to match with numeric dtypes in :meth:`DataFrame.describe` (:issue:`30164`)
--
+- :meth:`Groupby.groups` now returns an abbreviated representation when called on large dataframes (:issue:`1135`)
 
 Backwards incompatible API changes
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -148,7 +148,7 @@ Indexing
 ^^^^^^^^
 - Bug in slicing on a :class:`DatetimeIndex` with a partial-timestamp dropping high-resolution indices near the end of a year, quarter, or month (:issue:`31064`)
 - Bug in :meth:`PeriodIndex.get_loc` treating higher-resolution strings differently from :meth:`PeriodIndex.get_value` (:issue:`31172`)
--
+- Bug in :meth:`Series.at` and :meth:`DataFrame.at` not matching ``.loc`` behavior when looking up an integer in a :class:`Float64Index` (:issue:`31329`)
 
 Missing
 ^^^^^^^

pandas/_typing.py

@@ -45,6 +45,7 @@
 # other
 
 Dtype = Union[str, np.dtype, "ExtensionDtype"]
+DtypeObj = Union[np.dtype, "ExtensionDtype"]
 FilePathOrBuffer = Union[str, Path, IO[AnyStr]]
 
 # FrameOrSeriesUnion  means either a DataFrame or a Series. E.g.

pandas/core/base.py

@@ -1,6 +1,7 @@
 """
 Base and utility classes for pandas objects.
 """
+
 import builtins
 import textwrap
 from typing import Dict, FrozenSet, List, Optional, Union
@@ -45,11 +46,15 @@
 
 
 class PandasObject(DirNamesMixin):
-    """baseclass for various pandas objects"""
+    """
+    Baseclass for various pandas objects.
+    """
 
     @property
     def _constructor(self):
-        """class constructor (for this class it's just `__class__`"""
+        """
+        Class constructor (for this class it's just `__class__`.
+        """
         return type(self)
 
     def __repr__(self) -> str:
@@ -77,16 +82,14 @@ def __sizeof__(self):
         """
         if hasattr(self, "memory_usage"):
             mem = self.memory_usage(deep=True)
-            if not is_scalar(mem):
-                mem = mem.sum()
-            return int(mem)
+            return int(mem if is_scalar(mem) else mem.sum())
 
-        # no memory_usage attribute, so fall back to
-        # object's 'sizeof'
+        # no memory_usage attribute, so fall back to object's 'sizeof'
         return super().__sizeof__()
 
     def _ensure_type(self: T, obj) -> T:
-        """Ensure that an object has same type as self.
+        """
+        Ensure that an object has same type as self.
 
         Used by type checkers.
         """
@@ -95,7 +98,8 @@ def _ensure_type(self: T, obj) -> T:
 
 
 class NoNewAttributesMixin:
-    """Mixin which prevents adding new attributes.
+    """
+    Mixin which prevents adding new attributes.
 
     Prevents additional attributes via xxx.attribute = "something" after a
     call to `self.__freeze()`. Mainly used to prevent the user from using
@@ -106,7 +110,9 @@ class NoNewAttributesMixin:
     """
 
     def _freeze(self):
-        """Prevents setting additional attributes"""
+        """
+        Prevents setting additional attributes.
+        """
         object.__setattr__(self, "__frozen", True)
 
     # prevent adding any attribute via s.xxx.new_attribute = ...
@@ -180,14 +186,12 @@ class SelectionMixin:
     @property
     def _selection_name(self):
         """
-        return a name for myself; this would ideally be called
-        the 'name' property, but we cannot conflict with the
-        Series.name property which can be set
+        Return a name for myself;
+
+        This would ideally be called the 'name' property,
+        but we cannot conflict with the Series.name property which can be set.
         """
-        if self._selection is None:
-            return None  # 'result'
-        else:
-            return self._selection
+        return self._selection
 
     @property
     def _selection_list(self):
@@ -199,7 +203,6 @@ def _selection_list(self):
 
     @cache_readonly
     def _selected_obj(self):
-
         if self._selection is None or isinstance(self.obj, ABCSeries):
             return self.obj
         else:
@@ -246,12 +249,11 @@ def _gotitem(self, key, ndim: int, subset=None):
 
         Parameters
         ----------
-        key : string / list of selections
+        key : str / list of selections
         ndim : 1,2
             requested ndim of result
         subset : object, default None
             subset to act on
-
         """
         raise AbstractMethodError(self)
 
@@ -266,7 +268,6 @@ def _try_aggregate_string_function(self, arg: str, *args, **kwargs):
         - try to find a function (or attribute) on ourselves
         - try to find a numpy function
         - raise
-
         """
         assert isinstance(arg, str)
 
@@ -585,7 +586,6 @@ def _shallow_copy(self, obj, **kwargs):
         """
         return a new object with the replacement attributes
         """
-
         if isinstance(obj, self._constructor):
             obj = obj.obj
         for attr in self._attributes:
@@ -669,8 +669,7 @@ def item(self):
 
         if len(self) == 1:
             return next(iter(self))
-        else:
-            raise ValueError("can only convert an array of size 1 to a Python scalar")
+        raise ValueError("can only convert an array of size 1 to a Python scalar")
 
     @property
     def nbytes(self) -> int:
@@ -735,7 +734,6 @@ def array(self) -> ExtensionArray:
 
         Examples
         --------
-
         For regular NumPy types like int, and float, a PandasArray
         is returned.
 
@@ -851,12 +849,11 @@ def to_numpy(self, dtype=None, copy=False, na_value=lib.no_default, **kwargs):
         """
         if is_extension_array_dtype(self.dtype):
             return self.array.to_numpy(dtype, copy=copy, na_value=na_value, **kwargs)
-        else:
-            if kwargs:
-                msg = "to_numpy() got an unexpected keyword argument '{}'".format(
-                    list(kwargs.keys())[0]
-                )
-                raise TypeError(msg)
+        elif kwargs:
+            bad_keys = list(kwargs.keys())[0]
+            raise TypeError(
+                f"to_numpy() got an unexpected keyword argument '{bad_keys}'"
+            )
 
         result = np.asarray(self._values, dtype=dtype)
         # TODO(GH-24345): Avoid potential double copy
@@ -1076,7 +1073,9 @@ def _reduce(
         filter_type=None,
         **kwds,
     ):
-        """ perform the reduction type operation if we can """
+        """
+        Perform the reduction type operation if we can.
+        """
         func = getattr(self, name, None)
         if func is None:
             raise TypeError(
@@ -1103,9 +1102,7 @@ def _map_values(self, mapper, na_action=None):
             The output of the mapping function applied to the index.
             If the function returns a tuple with more than one element
             a MultiIndex will be returned.
-
         """
-
         # we can fastpath dict/Series to an efficient map
         # as we know that we are not going to have to yield
         # python types
@@ -1341,7 +1338,9 @@ def is_monotonic(self) -> bool:
 
     @property
     def is_monotonic_increasing(self) -> bool:
-        """alias for is_monotonic"""
+        """
+        Alias for is_monotonic.
+        """
         # mypy complains if we alias directly
         return self.is_monotonic
 
@@ -1455,7 +1454,6 @@ def factorize(self, sort=False, na_sentinel=-1):
 
         Examples
         --------
-
         >>> x = pd.Series([1, 2, 3])
         >>> x
         0    1

pandas/core/common.py

@@ -72,16 +72,6 @@ def consensus_name_attr(objs):
     return name
 
 
-def maybe_box(indexer, values, obj, key):
-
-    # if we have multiples coming back, box em
-    if isinstance(values, np.ndarray):
-        return obj[indexer.get_loc(key)]
-
-    # return the value
-    return values
-
-
 def maybe_box_datetimelike(value):
     # turn a datetime like into a Timestamp/timedelta as needed