Merge remote-tracking branch 'upstream/master' into groupby_agg_methods

Author: simonjayhawkins

doc/source/whatsnew/v1.0.2.rst

@@ -74,6 +74,7 @@ Bug fixes
 **I/O**
 
 - Using ``pd.NA`` with :meth:`DataFrame.to_json` now correctly outputs a null value instead of an empty object (:issue:`31615`)
+- Fixed pickling of ``pandas.NA``. Previously a new object was returned, which broke computations relying on ``NA`` being a singleton (:issue:`31847`)
 - Fixed bug in parquet roundtrip with nullable unsigned integer dtypes (:issue:`31896`).
 
 **Experimental dtypes**

doc/source/whatsnew/v1.1.0.rst

@@ -66,6 +66,7 @@ Other enhancements
 - :class:`Styler` may now render CSS more efficiently where multiple cells have the same styling (:issue:`30876`)
 - When writing directly to a sqlite connection :func:`to_sql` now supports the ``multi`` method (:issue:`29921`)
 - `OptionError` is now exposed in `pandas.errors` (:issue:`27553`)
+- :func:`timedelta_range` will now infer a frequency when passed ``start``, ``stop``, and ``periods`` (:issue:`32377`)
 -
 
 .. ---------------------------------------------------------------------------
@@ -198,6 +199,7 @@ Categorical
 
 - Bug where :func:`merge` was unable to join on non-unique categorical indices (:issue:`28189`)
 - Bug when passing categorical data to :class:`Index` constructor along with ``dtype=object`` incorrectly returning a :class:`CategoricalIndex` instead of object-dtype :class:`Index` (:issue:`32167`)
+- Bug where :class:`Categorical` comparison operator ``__ne__`` would incorrectly evaluate to ``False`` when either element was missing (:issue:`32276`)
 -
 
 Datetimelike
@@ -213,6 +215,7 @@ Timedelta
 ^^^^^^^^^
 
 - Bug in constructing a :class:`Timedelta` with a high precision integer that would round the :class:`Timedelta` components (:issue:`31354`)
+- Bug in dividing ``np.nan`` or ``None`` by :class:`Timedelta`` incorrectly returning ``NaT`` (:issue:`31869`)
 -
 
 Timezones
@@ -295,8 +298,10 @@ I/O
 - Bug in :meth:`DataFrame.to_parquet` overwriting pyarrow's default for
   ``coerce_timestamps``; following pyarrow's default allows writing nanosecond
   timestamps with ``version="2.0"`` (:issue:`31652`).
+- Bug in :meth:`read_csv` was raising `TypeError` when `sep=None` was used in combination with `comment` keyword (:issue:`31396`)
 - Bug in :class:`HDFStore` that caused it to set to ``int64`` the dtype of a ``datetime64`` column when reading a DataFrame in Python 3 from fixed format written in Python 2 (:issue:`31750`)
 
+
 Plotting
 ^^^^^^^^
 
@@ -322,6 +327,7 @@ Reshaping
 - Bug in :func:`crosstab` when inputs are two Series and have tuple names, the output will keep dummy MultiIndex as columns. (:issue:`18321`)
 - :meth:`DataFrame.pivot` can now take lists for ``index`` and ``columns`` arguments (:issue:`21425`)
 - Bug in :func:`concat` where the resulting indices are not copied when ``copy=True`` (:issue:`29879`)
+- :meth:`DataFrame.replace` and :meth:`Series.replace` will raise a ``TypeError`` if ``to_replace`` is not an expected type. Previously the ``replace`` would fail silently (:issue:`18634`)
 
 
 Sparse

pandas/_libs/lib.pyx

@@ -100,11 +100,9 @@ def values_from_object(obj: object):
     """
     func: object
 
-    if getattr(obj, '_typ', '') == 'dataframe':
-        return obj.values
-
     func = getattr(obj, '_internal_get_values', None)
     if func is not None:
+        # Includes DataFrame, for which we get frame.values
         obj = func()
 
     return obj

pandas/_libs/missing.pyx

@@ -10,10 +10,13 @@ cnp.import_array()
 
 cimport pandas._libs.util as util
 
-from pandas._libs.tslibs.np_datetime cimport (
-    get_timedelta64_value, get_datetime64_value)
+
+from pandas._libs.tslibs.np_datetime cimport get_datetime64_value, get_timedelta64_value
 from pandas._libs.tslibs.nattype cimport (
-    checknull_with_nat, c_NaT as NaT, is_null_datetimelike)
+    c_NaT as NaT,
+    checknull_with_nat,
+    is_null_datetimelike,
+)
 from pandas._libs.ops_dispatch import maybe_dispatch_ufunc_to_dunder_op
 
 from pandas.compat import is_platform_32bit
@@ -44,7 +47,7 @@ cpdef bint checknull(object val):
 
     Returns
     -------
-    result : bool
+    bool
 
     Notes
     -----
@@ -223,7 +226,7 @@ def isnaobj2d_old(arr: ndarray) -> ndarray:
 
     Returns
     -------
-    result : ndarray (dtype=np.bool_)
+    ndarray (dtype=np.bool_)
 
     Notes
     -----
@@ -248,17 +251,11 @@ def isnaobj2d_old(arr: ndarray) -> ndarray:
 
 
 def isposinf_scalar(val: object) -> bool:
-    if util.is_float_object(val) and val == INF:
-        return True
-    else:
-        return False
+    return util.is_float_object(val) and val == INF
 
 
 def isneginf_scalar(val: object) -> bool:
-    if util.is_float_object(val) and val == NEGINF:
-        return True
-    else:
-        return False
+    return util.is_float_object(val) and val == NEGINF
 
 
 cdef inline bint is_null_datetime64(v):
@@ -364,6 +361,9 @@ class NAType(C_NAType):
         exponent = 31 if is_32bit else 61
         return 2 ** exponent - 1
 
+    def __reduce__(self):
+        return "NA"
+
     # Binary arithmetic and comparison ops -> propagate
 
     __add__ = _create_binary_propagating_op("__add__")
@@ -423,7 +423,6 @@ class NAType(C_NAType):
                 return NA
         elif isinstance(other, np.ndarray):
             return np.where(other == 1, other, NA)
-
         return NotImplemented
 
     # Logical ops using Kleene logic
@@ -433,8 +432,7 @@ class NAType(C_NAType):
             return False
         elif other is True or other is C_NA:
             return NA
-        else:
-            return NotImplemented
+        return NotImplemented
 
     __rand__ = __and__
 
@@ -443,8 +441,7 @@ class NAType(C_NAType):
             return True
         elif other is False or other is C_NA:
             return NA
-        else:
-            return NotImplemented
+        return NotImplemented
 
     __ror__ = __or__
 

pandas/_libs/tslibs/timedeltas.pyx

@@ -1407,15 +1407,23 @@ class Timedelta(_Timedelta):
             # convert to Timedelta below
             pass
 
+        elif util.is_nan(other):
+            # i.e. np.nan or np.float64("NaN")
+            raise TypeError("Cannot divide float by Timedelta")
+
         elif hasattr(other, 'dtype'):
+            if other.dtype.kind == "O":
+                # GH#31869
+                return np.array([x / self for x in other])
             return other / self.to_timedelta64()
 
         elif not _validate_ops_compat(other):
             return NotImplemented
 
         other = Timedelta(other)
         if other is NaT:
-            return NaT
+            # In this context we treat NaT as timedelta-like
+            return np.nan
         return float(other.value) / self.value
 
     def __floordiv__(self, other):

pandas/_testing.py

@@ -742,9 +742,9 @@ def repr_class(x):
             raise_assert_detail(obj, msg, repr_class(left), repr_class(right))
 
 
-def assert_attr_equal(attr, left, right, obj="Attributes"):
+def assert_attr_equal(attr: str, left, right, obj: str = "Attributes"):
     """
-    checks attributes are equal. Both objects must have attribute.
+    Check attributes are equal. Both objects must have attribute.
 
     Parameters
     ----------

pandas/_typing.py

@@ -64,7 +64,7 @@
 Label = Optional[Hashable]
 Level = Union[Label, int]
 Ordered = Optional[bool]
-JSONSerializable = Union[PythonScalar, List, Dict]
+JSONSerializable = Optional[Union[PythonScalar, List, Dict]]
 Axes = Collection
 
 # For functions like rename that convert one label to another

pandas/conftest.py

@@ -1047,6 +1047,16 @@ def series_with_simple_index(indices):
     for dtype in _narrow_dtypes
 }
 
+
+@pytest.fixture(params=_narrow_series.keys())
+def narrow_series(request):
+    """
+    Fixture for Series with low precision data types
+    """
+    # copy to avoid mutation, e.g. setting .name
+    return _narrow_series[request.param].copy()
+
+
 _index_or_series_objs = {**indices_dict, **_series, **_narrow_series}
 
 

pandas/core/algorithms.py

@@ -313,8 +313,8 @@ def unique(values):
 
     See Also
     --------
-    Index.unique
-    Series.unique
+    Index.unique : Return unique values from an Index.
+    Series.unique : Return unique values of Series object.
 
     Examples
     --------
@@ -1515,7 +1515,7 @@ def take(arr, indices, axis: int = 0, allow_fill: bool = False, fill_value=None)
 
     See Also
     --------
-    numpy.take
+    numpy.take : Take elements from an array along an axis.
 
     Examples
     --------

pandas/core/arrays/categorical.py

@@ -103,7 +103,10 @@ def func(self, other):
             mask = (self._codes == -1) | (other_codes == -1)
             if mask.any():
                 # In other series, the leads to False, so do that here too
-                ret[mask] = False
+                if opname == "__ne__":
+                    ret[(self._codes == -1) & (other_codes == -1)] = True
+                else:
+                    ret[mask] = False
             return ret
 
         if is_scalar(other):