BUG: Posix / pytest (actions-39-numpydev.yaml, ...) checks failing on master

[KrishnaSai2020]

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pandas.

• (optional) I have confirmed this bug exists on the master branch of pandas.

---

Posix Checks are failing on master affecting all pr's. If you take a look at any recent pr's eg #42690 #42705 #42809 and #42701 you can see that they had 24/25 checks successful and it is the same check failing for all of them. Needs discussion

=================================== FAILURES ===================================
___________________________________ test_agg ___________________________________
[gw1] linux -- Python 3.9.5 /usr/share/miniconda/envs/pandas-dev/bin/python

self = <pandas.core.groupby.generic.SeriesGroupBy object at 0x7f1fdee50760>
how = 'group_var', cython_dtype = dtype('float64'), aggregate = True
numeric_only = False, needs_counts = True, needs_values = True, needs_2d = True
needs_nullable = False, min_count = None, needs_mask = False
needs_ngroups = False, result_is_index = False, pre_processing = None
post_processing = <function GroupBy.std.<locals>.<lambda> at 0x7f1fdee52040>
fill_value = None, kwargs = {'ddof': 1}
grouper = <pandas.core.groupby.ops.BinGrouper object at 0x7f1fdee4e430>
ids = array([0, 0, 1, 1, 2, 2, 3, 3, 4, 4]), _ = array([0, 1, 2, 3, 4])
output = {}
blk_func = <function GroupBy._get_cythonized_result.<locals>.blk_func at 0x7f1fdee52310>
error_msg = 'Cannot cast DatetimeArray to dtype float64', idx = 0

    @final
    def _get_cythonized_result(
        self,
        how: str,
        cython_dtype: np.dtype,
        aggregate: bool = False,
        numeric_only: bool | lib.NoDefault = lib.no_default,
        needs_counts: bool = False,
        needs_values: bool = False,
        needs_2d: bool = False,
        needs_nullable: bool = False,
        min_count: int | None = None,
        needs_mask: bool = False,
        needs_ngroups: bool = False,
        result_is_index: bool = False,
        pre_processing=None,
        post_processing=None,
        fill_value=None,
        **kwargs,
    ):
        """
        Get result for Cythonized functions.
    
        Parameters
        ----------
        how : str, Cythonized function name to be called
        cython_dtype : np.dtype
            Type of the array that will be modified by the Cython call.
        aggregate : bool, default False
            Whether the result should be aggregated to match the number of
            groups
        numeric_only : bool, default True
            Whether only numeric datatypes should be computed
        needs_counts : bool, default False
            Whether the counts should be a part of the Cython call
        needs_values : bool, default False
            Whether the values should be a part of the Cython call
            signature
        needs_2d : bool, default False
            Whether the values and result of the Cython call signature
            are 2-dimensional.
        min_count : int, default None
            When not None, min_count for the Cython call
        needs_mask : bool, default False
            Whether boolean mask needs to be part of the Cython call
            signature
        needs_ngroups : bool, default False
            Whether number of groups is part of the Cython call signature
        needs_nullable : bool, default False
            Whether a bool specifying if the input is nullable is part
            of the Cython call signature
        result_is_index : bool, default False
            Whether the result of the Cython operation is an index of
            values to be retrieved, instead of the actual values themselves
        pre_processing : function, default None
            Function to be applied to `values` prior to passing to Cython.
            Function should return a tuple where the first element is the
            values to be passed to Cython and the second element is an optional
            type which the values should be converted to after being returned
            by the Cython operation. This function is also responsible for
            raising a TypeError if the values have an invalid type. Raises
            if `needs_values` is False.
        post_processing : function, default None
            Function to be applied to result of Cython function. Should accept
            an array of values as the first argument and type inferences as its
            second argument, i.e. the signature should be
            (ndarray, Type). If `needs_nullable=True`, a third argument should be
            `nullable`, to allow for processing specific to nullable values.
        fill_value : any, default None
            The scalar value to use for newly introduced missing values.
        **kwargs : dict
            Extra arguments to be passed back to Cython funcs
    
        Returns
        -------
        `Series` or `DataFrame`  with filled values
        """
        numeric_only = self._resolve_numeric_only(numeric_only)
    
        if result_is_index and aggregate:
            raise ValueError("'result_is_index' and 'aggregate' cannot both be True!")
        if post_processing and not callable(post_processing):
            raise ValueError("'post_processing' must be a callable!")
        if pre_processing:
            if not callable(pre_processing):
                raise ValueError("'pre_processing' must be a callable!")
            if not needs_values:
                raise ValueError(
                    "Cannot use 'pre_processing' without specifying 'needs_values'!"
                )
    
        grouper = self.grouper
    
        ids, _, ngroups = grouper.group_info
        output: dict[base.OutputKey, ArrayLike] = {}
    
        base_func = getattr(libgroupby, how)
        base_func = partial(base_func, labels=ids)
        if needs_ngroups:
            base_func = partial(base_func, ngroups=ngroups)
        if min_count is not None:
            base_func = partial(base_func, min_count=min_count)
    
        def blk_func(values: ArrayLike) -> ArrayLike:
            if aggregate:
                result_sz = ngroups
            else:
                result_sz = len(values)
    
            result: ArrayLike
            result = np.zeros(result_sz, dtype=cython_dtype)
            if needs_2d:
                result = result.reshape((-1, 1))
            func = partial(base_func, out=result)
    
            inferences = None
    
            if needs_counts:
                counts = np.zeros(self.ngroups, dtype=np.int64)
                func = partial(func, counts=counts)
    
            if needs_values:
                vals = values
                if pre_processing:
                    vals, inferences = pre_processing(vals)
    
                vals = vals.astype(cython_dtype, copy=False)
                if needs_2d:
                    vals = vals.reshape((-1, 1))
                func = partial(func, values=vals)
    
            if needs_mask:
                mask = isna(values).view(np.uint8)
                func = partial(func, mask=mask)
    
            if needs_nullable:
                is_nullable = isinstance(values, BaseMaskedArray)
                func = partial(func, nullable=is_nullable)
    
            func(**kwargs)  # Call func to modify indexer values in place
    
            if needs_2d:
                result = result.reshape(-1)
    
            if result_is_index:
                result = algorithms.take_nd(values, result, fill_value=fill_value)
    
            if post_processing:
                pp_kwargs = {}
                if needs_nullable:
                    pp_kwargs["nullable"] = isinstance(values, BaseMaskedArray)
    
                result = post_processing(result, inferences, **pp_kwargs)
    
            return result
    
        error_msg = ""
        for idx, obj in enumerate(self._iterate_slices()):
            values = obj._values
    
            if numeric_only and not is_numeric_dtype(values.dtype):
                continue
    
            try:
>               result = blk_func(values)

pandas/core/groupby/groupby.py:2972: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

values = <DatetimeArray>
['2005-01-01 00:00:00', '2005-01-02 00:00:00', '2005-01-03 00:00:00',
 '2005-01-04 00:00:00', '2005-01...1-07 00:00:00', '2005-01-08 00:00:00', '2005-01-09 00:00:00',
 '2005-01-10 00:00:00']
Length: 10, dtype: datetime64[ns]

    def blk_func(values: ArrayLike) -> ArrayLike:
        if aggregate:
            result_sz = ngroups
        else:
            result_sz = len(values)
    
        result: ArrayLike
        result = np.zeros(result_sz, dtype=cython_dtype)
        if needs_2d:
            result = result.reshape((-1, 1))
        func = partial(base_func, out=result)
    
        inferences = None
    
        if needs_counts:
            counts = np.zeros(self.ngroups, dtype=np.int64)
            func = partial(func, counts=counts)
    
        if needs_values:
            vals = values
            if pre_processing:
                vals, inferences = pre_processing(vals)
    
>           vals = vals.astype(cython_dtype, copy=False)

pandas/core/groupby/groupby.py:2934: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <DatetimeArray>
['2005-01-01 00:00:00', '2005-01-02 00:00:00', '2005-01-03 00:00:00',
 '2005-01-04 00:00:00', '2005-01...1-07 00:00:00', '2005-01-08 00:00:00', '2005-01-09 00:00:00',
 '2005-01-10 00:00:00']
Length: 10, dtype: datetime64[ns]
dtype = dtype('float64'), copy = False

    def astype(self, dtype, copy: bool = True):
        # We handle
        #   --> datetime
        #   --> period
        # DatetimeLikeArrayMixin Super handles the rest.
        dtype = pandas_dtype(dtype)
    
        if is_dtype_equal(dtype, self.dtype):
            if copy:
                return self.copy()
            return self
    
        elif is_datetime64_ns_dtype(dtype):
            return astype_dt64_to_dt64tz(self, dtype, copy, via_utc=False)
    
        elif self.tz is None and is_datetime64_dtype(dtype) and dtype != self.dtype:
            # unit conversion e.g. datetime64[s]
            return self._ndarray.astype(dtype)
    
        elif is_period_dtype(dtype):
            return self.to_period(freq=dtype.freq)
>       return dtl.DatetimeLikeArrayMixin.astype(self, dtype, copy)

pandas/core/arrays/datetimes.py:651: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <DatetimeArray>
['2005-01-01 00:00:00', '2005-01-02 00:00:00', '2005-01-03 00:00:00',
 '2005-01-04 00:00:00', '2005-01...1-07 00:00:00', '2005-01-08 00:00:00', '2005-01-09 00:00:00',
 '2005-01-10 00:00:00']
Length: 10, dtype: datetime64[ns]
dtype = dtype('float64'), copy = False

    def astype(self, dtype, copy: bool = True):
        # Some notes on cases we don't have to handle here in the base class:
        #   1. PeriodArray.astype handles period -> period
        #   2. DatetimeArray.astype handles conversion between tz.
        #   3. DatetimeArray.astype handles datetime -> period
        dtype = pandas_dtype(dtype)
    
        if is_object_dtype(dtype):
            return self._box_values(self.asi8.ravel()).reshape(self.shape)
        elif is_string_dtype(dtype) and not is_categorical_dtype(dtype):
            if is_extension_array_dtype(dtype):
                arr_cls = dtype.construct_array_type()
                return arr_cls._from_sequence(self, dtype=dtype, copy=copy)
            else:
                return self._format_native_types()
        elif is_integer_dtype(dtype):
            # we deliberately ignore int32 vs. int64 here.
            # See https://github.com/pandas-dev/pandas/issues/24381 for more.
            level = find_stack_level()
            warnings.warn(
                f"casting {self.dtype} values to int64 with .astype(...) is "
                "deprecated and will raise in a future version. "
                "Use .view(...) instead.",
                FutureWarning,
                stacklevel=level,
            )
    
            values = self.asi8
    
            if is_unsigned_integer_dtype(dtype):
                # Again, we ignore int32 vs. int64
                values = values.view("uint64")
    
            if copy:
                values = values.copy()
            return values
        elif (
            is_datetime_or_timedelta_dtype(dtype)
            and not is_dtype_equal(self.dtype, dtype)
        ) or is_float_dtype(dtype):
            # disallow conversion between datetime/timedelta,
            # and conversions for any datetimelike to float
            msg = f"Cannot cast {type(self).__name__} to dtype {dtype}"
>           raise TypeError(msg)
E           TypeError: Cannot cast DatetimeArray to dtype float64

pandas/core/arrays/datetimelike.py:424: TypeError

During handling of the above exception, another exception occurred:

    def test_agg():
        # test with all three Resampler apis and TimeGrouper
    
        np.random.seed(1234)
        index = date_range(datetime(2005, 1, 1), datetime(2005, 1, 10), freq="D")
        index.name = "date"
        df = DataFrame(np.random.rand(10, 2), columns=list("AB"), index=index)
        df_col = df.reset_index()
        df_mult = df_col.copy()
        df_mult.index = pd.MultiIndex.from_arrays(
            [range(10), df.index], names=["index", "date"]
        )
        r = df.resample("2D")
        cases = [
            r,
            df_col.resample("2D", on="date"),
            df_mult.resample("2D", level="date"),
            df.groupby(pd.Grouper(freq="2D")),
        ]
    
        a_mean = r["A"].mean()
        a_std = r["A"].std()
        a_sum = r["A"].sum()
        b_mean = r["B"].mean()
        b_std = r["B"].std()
        b_sum = r["B"].sum()
    
        expected = pd.concat([a_mean, a_std, b_mean, b_std], axis=1)
        expected.columns = pd.MultiIndex.from_product([["A", "B"], ["mean", "std"]])
        for t in cases:
>           result = t.aggregate([np.mean, np.std])

pandas/tests/resample/test_resample_api.py:352: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
pandas/core/resample.py:331: in aggregate
    result = ResamplerWindowApply(self, func, args=args, kwargs=kwargs).agg()
pandas/core/apply.py:164: in agg
    return self.agg_list_like()
pandas/core/apply.py:355: in agg_list_like
    new_res = colg.aggregate(arg)
pandas/core/groupby/generic.py:248: in aggregate
    ret = self._aggregate_multiple_funcs(func)
pandas/core/groupby/generic.py:302: in _aggregate_multiple_funcs
    results[key] = self.aggregate(func)
pandas/core/groupby/generic.py:258: in aggregate
    return getattr(self, cyfunc)()
pandas/core/groupby/groupby.py:1728: in std
    return self._get_cythonized_result(

[KrishnaSai2020]

Could someone add the needs discussion label please I don't how to?

[lithomas1]

Not an unreliable test, warning is consistently produced.