def infer_dtype_from_scalar(val, pandas_dtype=False):
"""
interpret the dtype from a scalar
Parameters
----------
pandas_dtype : bool, default False
whether to infer dtype including pandas extension types.
If False, scalar belongs to pandas extension types is inferred as
object
"""
dtype = np.object_
# a 1-element ndarray
if isinstance(val, np.ndarray):
msg = "invalid ndarray passed to infer_dtype_from_scalar"
if val.ndim != 0:
raise ValueError(msg)
dtype = val.dtype
val = val.item()
elif isinstance(val, string_types):
# If we create an empty array using a string to infer
# the dtype, NumPy will only allocate one character per entry
# so this is kind of bad. Alternately we could use np.repeat
# instead of np.empty (but then you still don't want things
# coming out as np.str_!
dtype = np.object_
elif isinstance(val, (np.datetime64, datetime)):
val = tslibs.Timestamp(val)
if val is tslibs.NaT or val.tz is None:
dtype = np.dtype('M8[ns]')
else:
if pandas_dtype:
dtype = DatetimeTZDtype(unit='ns', tz=val.tz)
else:
# return datetimetz as object
return np.object_, val
val = val.value
elif isinstance(val, (np.timedelta64, timedelta)):
val = tslibs.Timedelta(val).value
dtype = np.dtype('m8[ns]')
elif is_bool(val):
dtype = np.bool_
elif is_integer(val):
if isinstance(val, np.integer):
dtype = type(val)
else:
dtype = np.int64
elif is_float(val):
if isinstance(val, np.floating):
dtype = type(val)
else:
dtype = np.float64
elif is_complex(val):
dtype = np.complex_
elif pandas_dtype:
if lib.is_period(val):
dtype = PeriodDtype(freq=val.freq)
val = val.ordinal
return dtype, val
def maybe_promote(dtype, fill_value=np.nan):
"""
Find the minimal dtype that can hold both the given dtype and fill_value.
Parameters
----------
dtype : np.dtype or ExtensionDtype
fill_value : scalar, default np.nan
Returns
-------
dtype
Upcasted from dtype argument if necessary.
fill_value
Upcasted from fill_value argument if necessary.
"""
if not is_scalar(fill_value) and not is_object_dtype(dtype):
# with object dtype there is nothing to promote, and the user can
# pass pretty much any weird fill_value they like
raise ValueError("fill_value must be a scalar")
# if we passed an array here, determine the fill value by dtype
if isinstance(fill_value, np.ndarray):
if issubclass(fill_value.dtype.type, (np.datetime64, np.timedelta64)):
fill_value = fill_value.dtype.type("NaT", "ns")
else:
# we need to change to object type as our
# fill_value is of object type
if fill_value.dtype == np.object_:
dtype = np.dtype(np.object_)
fill_value = np.nan
if dtype == np.object_ or dtype.kind in ["U", "S"]:
# We treat string-like dtypes as object, and _always_ fill
# with np.nan
fill_value = np.nan
dtype = np.dtype(np.object_)
# returns tuple of (dtype, fill_value)
if issubclass(dtype.type, np.datetime64):
if isinstance(fill_value, datetime) and fill_value.tzinfo is not None:
# Trying to insert tzaware into tznaive, have to cast to object
dtype = np.dtype(np.object_)
elif is_integer(fill_value) or (is_float(fill_value)
and not isna(fill_value)):
dtype = np.dtype(np.object_)
else:
try:
fill_value = tslibs.Timestamp(fill_value).to_datetime64()
except (TypeError, ValueError):
dtype = np.dtype(np.object_)
elif issubclass(dtype.type, np.timedelta64):
if (is_integer(fill_value)
or (is_float(fill_value) and not np.isnan(fill_value))
or isinstance(fill_value, str)):
# TODO: What about str that can be a timedelta?
dtype = np.dtype(np.object_)
else:
try:
fv = tslibs.Timedelta(fill_value)
except ValueError:
dtype = np.dtype(np.object_)
else:
if fv is NaT:
# NaT has no `to_timedelta64` method
fill_value = np.timedelta64("NaT", "ns")
else:
fill_value = fv.to_timedelta64()
elif is_datetime64tz_dtype(dtype):
if isna(fill_value):
fill_value = NaT
elif not isinstance(fill_value, datetime):
dtype = np.dtype(np.object_)
elif fill_value.tzinfo is None:
dtype = np.dtype(np.object_)
elif not tz_compare(fill_value.tzinfo, dtype.tz):
# TODO: sure we want to cast here?
dtype = np.dtype(np.object_)
elif is_extension_array_dtype(dtype) and isna(fill_value):
fill_value = dtype.na_value
elif is_float(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.dtype(np.object_)
elif issubclass(dtype.type, np.integer):
dtype = np.dtype(np.float64)
elif dtype.kind == "f":
mst = np.min_scalar_type(fill_value)
if mst > dtype:
# e.g. mst is np.float64 and dtype is np.float32
dtype = mst
elif dtype.kind == "c":
mst = np.min_scalar_type(fill_value)
dtype = np.promote_types(dtype, mst)
elif is_bool(fill_value):
if not issubclass(dtype.type, np.bool_):
dtype = np.dtype(np.object_)
elif is_integer(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.dtype(np.object_)
elif issubclass(dtype.type, np.integer):
if not np.can_cast(fill_value, dtype):
# upcast to prevent overflow
mst = np.min_scalar_type(fill_value)
dtype = np.promote_types(dtype, mst)
if dtype.kind == "f":
# Case where we disagree with numpy
dtype = np.dtype(np.object_)
elif is_complex(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.dtype(np.object_)
elif issubclass(dtype.type, (np.integer, np.floating)):
mst = np.min_scalar_type(fill_value)
dtype = np.promote_types(dtype, mst)
elif dtype.kind == "c":
mst = np.min_scalar_type(fill_value)
if mst > dtype:
# e.g. mst is np.complex128 and dtype is np.complex64
dtype = mst
elif fill_value is None:
if is_float_dtype(dtype) or is_complex_dtype(dtype):
fill_value = np.nan
elif is_integer_dtype(dtype):
dtype = np.float64
fill_value = np.nan
elif is_datetime_or_timedelta_dtype(dtype):
fill_value = dtype.type("NaT", "ns")
else:
dtype = np.dtype(np.object_)
fill_value = np.nan
else:
dtype = np.dtype(np.object_)
# in case we have a string that looked like a number
if is_extension_array_dtype(dtype):
pass
elif issubclass(np.dtype(dtype).type, (bytes, str)):
dtype = np.dtype(np.object_)
fill_value = _ensure_dtype_type(fill_value, dtype)
return dtype, fill_value
def maybe_promote(dtype, fill_value=np.nan):
# if we passed an array here, determine the fill value by dtype
if isinstance(fill_value, np.ndarray):
if issubclass(fill_value.dtype.type, (np.datetime64, np.timedelta64)):
fill_value = iNaT
else:
# we need to change to object type as our
# fill_value is of object type
if fill_value.dtype == np.object_:
dtype = np.dtype(np.object_)
fill_value = np.nan
# returns tuple of (dtype, fill_value)
if issubclass(dtype.type, np.datetime64):
fill_value = tslibs.Timestamp(fill_value).value
elif issubclass(dtype.type, np.timedelta64):
fill_value = tslibs.Timedelta(fill_value).value
elif is_datetime64tz_dtype(dtype):
if isna(fill_value):
fill_value = NaT
elif is_extension_array_dtype(dtype) and isna(fill_value):
fill_value = dtype.na_value
elif is_float(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.object_
elif issubclass(dtype.type, np.integer):
dtype = np.float64
elif is_bool(fill_value):
if not issubclass(dtype.type, np.bool_):
dtype = np.object_
elif is_integer(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.object_
elif issubclass(dtype.type, np.integer):
# upcast to prevent overflow
arr = np.asarray(fill_value)
if arr != arr.astype(dtype):
dtype = arr.dtype
elif is_complex(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.object_
elif issubclass(dtype.type, (np.integer, np.floating)):
dtype = np.complex128
elif fill_value is None:
if is_float_dtype(dtype) or is_complex_dtype(dtype):
fill_value = np.nan
elif is_integer_dtype(dtype):
dtype = np.float64
fill_value = np.nan
elif is_datetime_or_timedelta_dtype(dtype):
fill_value = iNaT
else:
dtype = np.object_
fill_value = np.nan
else:
dtype = np.object_
# in case we have a string that looked like a number
if is_extension_array_dtype(dtype):
pass
elif is_datetime64tz_dtype(dtype):
pass
elif issubclass(np.dtype(dtype).type, string_types):
dtype = np.object_
return dtype, fill_value
def _adjust_to_origin(arg, origin, unit):
"""
Helper function for to_datetime.
Adjust input argument to the specified origin
Parameters
----------
arg : list, tuple, ndarray, Series, Index
date to be adjusted
origin : 'julian' or Timestamp
origin offset for the arg
unit : string
passed unit from to_datetime, must be 'D'
Returns
-------
ndarray or scalar of adjusted date(s)
"""
if origin == "julian":
original = arg
j0 = Timestamp(0).to_julian_date()
if unit != "D":
raise ValueError("unit must be 'D' for origin='julian'")
try:
arg = arg - j0
except TypeError as err:
raise ValueError(
"incompatible 'arg' type for given 'origin'='julian'") from err
# preemptively check this for a nice range
j_max = Timestamp.max.to_julian_date() - j0
j_min = Timestamp.min.to_julian_date() - j0
if np.any(arg > j_max) or np.any(arg < j_min):
raise tslibs.OutOfBoundsDatetime(
f"{original} is Out of Bounds for origin='julian'")
else:
# arg must be numeric
if not ((is_scalar(arg) and (is_integer(arg) or is_float(arg)))
or is_numeric_dtype(np.asarray(arg))):
raise ValueError(
f"'{arg}' is not compatible with origin='{origin}'; "
"it must be numeric with a unit specified")
# we are going to offset back to unix / epoch time
try:
offset = Timestamp(origin)
except tslibs.OutOfBoundsDatetime as err:
raise tslibs.OutOfBoundsDatetime(
f"origin {origin} is Out of Bounds") from err
except ValueError as err:
raise ValueError(
f"origin {origin} cannot be converted to a Timestamp") from err
if offset.tz is not None:
raise ValueError(f"origin offset {offset} must be tz-naive")
offset -= Timestamp(0)
# convert the offset to the unit of the arg
# this should be lossless in terms of precision
offset = offset // tslibs.Timedelta(1, unit=unit)
# scalars & ndarray-like can handle the addition
if is_list_like(arg) and not isinstance(
arg, (ABCSeries, ABCIndexClass, np.ndarray)):
arg = np.asarray(arg)
arg = arg + offset
return arg
def maybe_promote(dtype, fill_value=np.nan):
# if we passed an array here, determine the fill value by dtype
if isinstance(fill_value, np.ndarray):
if issubclass(fill_value.dtype.type, (np.datetime64, np.timedelta64)):
fill_value = iNaT
else:
# we need to change to object type as our
# fill_value is of object type
if fill_value.dtype == np.object_:
dtype = np.dtype(np.object_)
fill_value = np.nan
# returns tuple of (dtype, fill_value)
if issubclass(dtype.type, (np.datetime64, np.timedelta64)):
# for now: refuse to upcast datetime64
# (this is because datetime64 will not implicitly upconvert
# to object correctly as of numpy 1.6.1)
if isna(fill_value):
fill_value = iNaT
else:
if issubclass(dtype.type, np.datetime64):
try:
fill_value = tslibs.Timestamp(fill_value).value
except Exception:
# the proper thing to do here would probably be to upcast
# to object (but numpy 1.6.1 doesn't do this properly)
fill_value = iNaT
elif issubclass(dtype.type, np.timedelta64):
try:
fill_value = tslibs.Timedelta(fill_value).value
except Exception:
# as for datetimes, cannot upcast to object
fill_value = iNaT
else:
fill_value = iNaT
elif is_datetimetz(dtype):
if isna(fill_value):
fill_value = iNaT
elif is_extension_array_dtype(dtype) and isna(fill_value):
fill_value = dtype.na_value
elif is_float(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.object_
elif issubclass(dtype.type, np.integer):
dtype = np.float64
elif is_bool(fill_value):
if not issubclass(dtype.type, np.bool_):
dtype = np.object_
elif is_integer(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.object_
elif issubclass(dtype.type, np.integer):
# upcast to prevent overflow
arr = np.asarray(fill_value)
if arr != arr.astype(dtype):
dtype = arr.dtype
elif is_complex(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.object_
elif issubclass(dtype.type, (np.integer, np.floating)):
dtype = np.complex128
elif fill_value is None:
if is_float_dtype(dtype) or is_complex_dtype(dtype):
fill_value = np.nan
elif is_integer_dtype(dtype):
dtype = np.float64
fill_value = np.nan
elif is_datetime_or_timedelta_dtype(dtype):
fill_value = iNaT
else:
dtype = np.object_
fill_value = np.nan
else:
dtype = np.object_
# in case we have a string that looked like a number
if is_extension_array_dtype(dtype):
pass
elif is_datetimetz(dtype):
pass
elif issubclass(np.dtype(dtype).type, string_types):
dtype = np.object_
return dtype, fill_value
def maybe_promote(dtype, fill_value=np.nan):
# if we passed an array here, determine the fill value by dtype
if isinstance(fill_value, np.ndarray):
if issubclass(fill_value.dtype.type, (np.datetime64, np.timedelta64)):
fill_value = fill_value.dtype.type("NaT", "ns")
else:
# we need to change to object type as our
# fill_value is of object type
if fill_value.dtype == np.object_:
dtype = np.dtype(np.object_)
fill_value = np.nan
if dtype == np.object_ or dtype.kind in ["U", "S"]:
# We treat string-like dtypes as object, and _always_ fill
# with np.nan
fill_value = np.nan
dtype = np.dtype(np.object_)
# returns tuple of (dtype, fill_value)
if issubclass(dtype.type, np.datetime64):
if isinstance(fill_value, datetime) and fill_value.tzinfo is not None:
# Trying to insert tzaware into tznaive, have to cast to object
dtype = np.dtype(np.object_)
else:
try:
fill_value = tslibs.Timestamp(fill_value).to_datetime64()
except (TypeError, ValueError):
dtype = np.dtype(np.object_)
elif issubclass(dtype.type, np.timedelta64):
try:
fv = tslibs.Timedelta(fill_value)
except ValueError:
dtype = np.dtype(np.object_)
else:
if fv is NaT:
# NaT has no `to_timedelta64` method
fill_value = np.timedelta64("NaT", "ns")
else:
fill_value = fv.to_timedelta64()
elif is_datetime64tz_dtype(dtype):
if isna(fill_value):
fill_value = NaT
elif is_extension_array_dtype(dtype) and isna(fill_value):
fill_value = dtype.na_value
elif is_float(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.object_
elif issubclass(dtype.type, np.integer):
dtype = np.dtype(np.float64)
if not isna(fill_value):
fill_value = dtype.type(fill_value)
elif is_bool(fill_value):
if not issubclass(dtype.type, np.bool_):
dtype = np.object_
else:
fill_value = np.bool_(fill_value)
elif is_integer(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.object_
elif issubclass(dtype.type, np.integer):
# upcast to prevent overflow
arr = np.asarray(fill_value)
if arr != arr.astype(dtype):
dtype = arr.dtype
elif issubclass(dtype.type, np.floating):
# check if we can cast
if _check_lossless_cast(fill_value, dtype):
fill_value = dtype.type(fill_value)
elif is_complex(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.object_
elif issubclass(dtype.type, (np.integer, np.floating)):
dtype = np.complex128
elif fill_value is None:
if is_float_dtype(dtype) or is_complex_dtype(dtype):
fill_value = np.nan
elif is_integer_dtype(dtype):
dtype = np.float64
fill_value = np.nan
elif is_datetime_or_timedelta_dtype(dtype):
fill_value = dtype.type("NaT", "ns")
else:
dtype = np.object_
fill_value = np.nan
else:
dtype = np.object_
# in case we have a string that looked like a number
if is_extension_array_dtype(dtype):
pass
elif issubclass(np.dtype(dtype).type, (bytes, str)):
dtype = np.object_
return dtype, fill_value
def maybe_promote(dtype, fill_value=np.nan):
# if we passed an array here, determine the fill value by dtype
if isinstance(fill_value, np.ndarray):
if issubclass(fill_value.dtype.type, (np.datetime64, np.timedelta64)):
fill_value = fill_value.dtype.type("NaT", "ns")
else:
# we need to change to object type as our
# fill_value is of object type
if fill_value.dtype == np.object_:
dtype = np.dtype(np.object_)
fill_value = np.nan
if dtype == np.object_ or dtype.kind in ["U", "S"]:
# We treat string-like dtypes as object, and _always_ fill
# with np.nan
fill_value = np.nan
dtype = np.dtype(np.object_)
# returns tuple of (dtype, fill_value)
if issubclass(dtype.type, np.datetime64):
if isinstance(fill_value, datetime) and fill_value.tzinfo is not None:
# Trying to insert tzaware into tznaive, have to cast to object
dtype = np.dtype(np.object_)
elif is_integer(fill_value) or (is_float(fill_value) and not isna(fill_value)):
dtype = np.dtype(np.object_)
else:
try:
fill_value = tslibs.Timestamp(fill_value).to_datetime64()
except (TypeError, ValueError):
dtype = np.dtype(np.object_)
elif issubclass(dtype.type, np.timedelta64):
if (
is_integer(fill_value)
or (is_float(fill_value) and not np.isnan(fill_value))
or isinstance(fill_value, str)
):
# TODO: What about str that can be a timedelta?
dtype = np.dtype(np.object_)
else:
try:
fv = tslibs.Timedelta(fill_value)
except ValueError:
dtype = np.dtype(np.object_)
else:
if fv is NaT:
# NaT has no `to_timedelta64` method
fill_value = np.timedelta64("NaT", "ns")
else:
fill_value = fv.to_timedelta64()
elif is_datetime64tz_dtype(dtype):
if isna(fill_value):
fill_value = NaT
elif is_extension_array_dtype(dtype) and isna(fill_value):
fill_value = dtype.na_value
elif is_float(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.object_
elif issubclass(dtype.type, np.integer):
dtype = np.dtype(np.float64)
if not isna(fill_value):
fill_value = dtype.type(fill_value)
elif dtype.kind == "f":
if not np.can_cast(fill_value, dtype):
# e.g. dtype is float32, need float64
dtype = np.min_scalar_type(fill_value)
elif dtype.kind == "c":
if not np.can_cast(fill_value, dtype):
if np.can_cast(fill_value, np.dtype("c16")):
dtype = np.dtype(np.complex128)
else:
dtype = np.dtype(np.object_)
if dtype.kind == "c" and not np.isnan(fill_value):
fill_value = dtype.type(fill_value)
elif is_bool(fill_value):
if not issubclass(dtype.type, np.bool_):
dtype = np.object_
else:
fill_value = np.bool_(fill_value)
elif is_integer(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.dtype(np.object_)
elif issubclass(dtype.type, np.integer):
# upcast to prevent overflow
mst = np.min_scalar_type(fill_value)
if mst > dtype:
# np.dtype ordering considers:
# int[n] < int[2*n]
# uint[n] < uint[2*n]
# u?int[n] < object_
dtype = mst
elif np.can_cast(fill_value, dtype):
pass
elif dtype.kind == "u" and mst.kind == "i":
dtype = np.promote_types(dtype, mst)
if dtype.kind == "f":
# Case where we disagree with numpy
dtype = np.dtype(np.object_)
elif dtype.kind == "i" and mst.kind == "u":
if fill_value > np.iinfo(np.int64).max:
# object is the only way to represent fill_value and keep
# the range allowed by the given dtype
dtype = np.dtype(np.object_)
elif mst.itemsize < dtype.itemsize:
pass
elif dtype.itemsize == mst.itemsize:
# We never cast signed to unsigned because that loses
# parts of the original range, so find the smallest signed
# integer that can hold all of `mst`.
ndt = {
np.int64: np.object_,
np.int32: np.int64,
np.int16: np.int32,
np.int8: np.int16,
}[dtype.type]
dtype = np.dtype(ndt)
else:
# bump to signed integer dtype that holds all of `mst` range
# Note: we have to use itemsize because some (windows)
# builds don't satisfiy e.g. np.uint32 == np.uint32
ndt = {
4: np.int64,
2: np.int32,
1: np.int16, # TODO: Test for this case
}[mst.itemsize]
dtype = np.dtype(ndt)
fill_value = dtype.type(fill_value)
elif issubclass(dtype.type, np.floating):
# check if we can cast
if _check_lossless_cast(fill_value, dtype):
fill_value = dtype.type(fill_value)
if dtype.kind in ["c", "f"]:
# e.g. if dtype is complex128 and fill_value is 1, we
# want np.complex128(1)
fill_value = dtype.type(fill_value)
elif is_complex(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.dtype(np.object_)
elif issubclass(dtype.type, (np.integer, np.floating)):
c8 = np.dtype(np.complex64)
info = np.finfo(dtype) if dtype.kind == "f" else np.iinfo(dtype)
if (
np.can_cast(fill_value, c8)
and np.can_cast(info.min, c8)
and np.can_cast(info.max, c8)
):
dtype = np.dtype(np.complex64)
else:
dtype = np.dtype(np.complex128)
elif dtype.kind == "c":
mst = np.min_scalar_type(fill_value)
if mst > dtype and mst.kind == "c":
# e.g. mst is np.complex128 and dtype is np.complex64
dtype = mst
if dtype.kind == "c":
# make sure we have a np.complex and not python complex
fill_value = dtype.type(fill_value)
elif fill_value is None:
if is_float_dtype(dtype) or is_complex_dtype(dtype):
fill_value = np.nan
elif is_integer_dtype(dtype):
dtype = np.float64
fill_value = np.nan
elif is_datetime_or_timedelta_dtype(dtype):
fill_value = dtype.type("NaT", "ns")
else:
dtype = np.object_
fill_value = np.nan
else:
dtype = np.object_
# in case we have a string that looked like a number
if is_extension_array_dtype(dtype):
pass
elif issubclass(np.dtype(dtype).type, (bytes, str)):
dtype = np.object_
return dtype, fill_value
def maybe_promote(dtype, fill_value=np.nan):
# if we passed an array here, determine the fill value by dtype
if isinstance(fill_value, np.ndarray):
if issubclass(fill_value.dtype.type, (np.datetime64, np.timedelta64)):
fill_value = fill_value.dtype.type("NaT", "ns")
else:
# we need to change to object type as our
# fill_value is of object type
if fill_value.dtype == np.object_:
dtype = np.dtype(np.object_)
fill_value = np.nan
if dtype == np.object_ or dtype.kind in ["U", "S"]:
# We treat string-like dtypes as object, and _always_ fill
# with np.nan
fill_value = np.nan
dtype = np.dtype(np.object_)
# returns tuple of (dtype, fill_value)
if issubclass(dtype.type, np.datetime64):
if isinstance(fill_value, datetime) and fill_value.tzinfo is not None:
# Trying to insert tzaware into tznaive, have to cast to object
dtype = np.dtype(np.object_)
elif is_integer(fill_value) or (is_float(fill_value)
and not isna(fill_value)):
dtype = np.dtype(np.object_)
else:
try:
fill_value = tslibs.Timestamp(fill_value).to_datetime64()
except (TypeError, ValueError):
dtype = np.dtype(np.object_)
elif issubclass(dtype.type, np.timedelta64):
if (is_integer(fill_value)
or (is_float(fill_value) and not np.isnan(fill_value))
or isinstance(fill_value, str)):
# TODO: What about str that can be a timedelta?
dtype = np.dtype(np.object_)
else:
try:
fv = tslibs.Timedelta(fill_value)
except ValueError:
dtype = np.dtype(np.object_)
else:
if fv is NaT:
# NaT has no `to_timedelta64` method
fill_value = np.timedelta64("NaT", "ns")
else:
fill_value = fv.to_timedelta64()
elif is_datetime64tz_dtype(dtype):
if isna(fill_value):
fill_value = NaT
elif is_extension_array_dtype(dtype) and isna(fill_value):
fill_value = dtype.na_value
elif is_float(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.object_
elif issubclass(dtype.type, np.integer):
dtype = np.dtype(np.float64)
if not isna(fill_value):
fill_value = dtype.type(fill_value)
elif dtype.kind == "f":
if not np.can_cast(fill_value, dtype):
# e.g. dtype is float32, need float64
dtype = np.min_scalar_type(fill_value)
elif dtype.kind == "c":
if not np.can_cast(fill_value, dtype):
if np.can_cast(fill_value, np.dtype("c16")):
dtype = np.dtype(np.complex128)
else:
dtype = np.dtype(np.object_)
if dtype.kind == "c" and not np.isnan(fill_value):
fill_value = dtype.type(fill_value)
elif is_bool(fill_value):
if not issubclass(dtype.type, np.bool_):
dtype = np.object_
else:
fill_value = np.bool_(fill_value)
elif is_integer(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.dtype(np.object_)
elif issubclass(dtype.type, np.integer):
if not np.can_cast(fill_value, dtype):
# upcast to prevent overflow
mst = np.min_scalar_type(fill_value)
dtype = np.promote_types(dtype, mst)
if dtype.kind == "f":
# Case where we disagree with numpy
dtype = np.dtype(np.object_)
fill_value = dtype.type(fill_value)
elif issubclass(dtype.type, np.floating):
# check if we can cast
if _check_lossless_cast(fill_value, dtype):
fill_value = dtype.type(fill_value)
if dtype.kind in ["c", "f"]:
# e.g. if dtype is complex128 and fill_value is 1, we
# want np.complex128(1)
fill_value = dtype.type(fill_value)
elif is_complex(fill_value):
if issubclass(dtype.type, np.bool_):
dtype = np.dtype(np.object_)
elif issubclass(dtype.type, (np.integer, np.floating)):
c8 = np.dtype(np.complex64)
info = np.finfo(dtype) if dtype.kind == "f" else np.iinfo(dtype)
if (np.can_cast(fill_value, c8) and np.can_cast(info.min, c8)
and np.can_cast(info.max, c8)):
dtype = np.dtype(np.complex64)
else:
dtype = np.dtype(np.complex128)
elif dtype.kind == "c":
mst = np.min_scalar_type(fill_value)
if mst > dtype and mst.kind == "c":
# e.g. mst is np.complex128 and dtype is np.complex64
dtype = mst
if dtype.kind == "c":
# make sure we have a np.complex and not python complex
fill_value = dtype.type(fill_value)
elif fill_value is None:
if is_float_dtype(dtype) or is_complex_dtype(dtype):
fill_value = np.nan
elif is_integer_dtype(dtype):
dtype = np.float64
fill_value = np.nan
elif is_datetime_or_timedelta_dtype(dtype):
fill_value = dtype.type("NaT", "ns")
else:
dtype = np.object_
fill_value = np.nan
else:
dtype = np.object_
# in case we have a string that looked like a number
if is_extension_array_dtype(dtype):
pass
elif issubclass(np.dtype(dtype).type, (bytes, str)):
dtype = np.object_
return dtype, fill_value
