projektAI/venv/Lib/site-packages/pandas/core/arrays/timedeltas.py
2021-06-06 22:13:05 +02:00

1085 lines
35 KiB
Python

from datetime import timedelta
from typing import List, Optional, Union
import numpy as np
from pandas._libs import lib, tslibs
from pandas._libs.tslibs import (
BaseOffset,
NaT,
NaTType,
Period,
Tick,
Timedelta,
Timestamp,
iNaT,
to_offset,
)
from pandas._libs.tslibs.conversion import precision_from_unit
from pandas._libs.tslibs.fields import get_timedelta_field
from pandas._libs.tslibs.timedeltas import (
array_to_timedelta64,
ints_to_pytimedelta,
parse_timedelta_unit,
)
from pandas.compat.numpy import function as nv
from pandas.core.dtypes.common import (
DT64NS_DTYPE,
TD64NS_DTYPE,
is_categorical_dtype,
is_dtype_equal,
is_float_dtype,
is_integer_dtype,
is_object_dtype,
is_scalar,
is_string_dtype,
is_timedelta64_dtype,
is_timedelta64_ns_dtype,
pandas_dtype,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.generic import ABCSeries, ABCTimedeltaIndex
from pandas.core.dtypes.missing import isna
from pandas.core import nanops
from pandas.core.algorithms import checked_add_with_arr
from pandas.core.arrays import IntegerArray, datetimelike as dtl
from pandas.core.arrays._ranges import generate_regular_range
import pandas.core.common as com
from pandas.core.construction import extract_array
from pandas.core.ops.common import unpack_zerodim_and_defer
def _field_accessor(name: str, alias: str, docstring: str):
def f(self) -> np.ndarray:
values = self.asi8
result = get_timedelta_field(values, alias)
if self._hasnans:
result = self._maybe_mask_results(
result, fill_value=None, convert="float64"
)
return result
f.__name__ = name
f.__doc__ = f"\n{docstring}\n"
return property(f)
class TimedeltaArray(dtl.TimelikeOps):
"""
Pandas ExtensionArray for timedelta data.
.. versionadded:: 0.24.0
.. warning::
TimedeltaArray is currently experimental, and its API may change
without warning. In particular, :attr:`TimedeltaArray.dtype` is
expected to change to be an instance of an ``ExtensionDtype``
subclass.
Parameters
----------
values : array-like
The timedelta data.
dtype : numpy.dtype
Currently, only ``numpy.dtype("timedelta64[ns]")`` is accepted.
freq : Offset, optional
copy : bool, default False
Whether to copy the underlying array of data.
Attributes
----------
None
Methods
-------
None
"""
_typ = "timedeltaarray"
_scalar_type = Timedelta
_recognized_scalars = (timedelta, np.timedelta64, Tick)
_is_recognized_dtype = is_timedelta64_dtype
_infer_matches = ("timedelta", "timedelta64")
__array_priority__ = 1000
# define my properties & methods for delegation
_other_ops: List[str] = []
_bool_ops: List[str] = []
_object_ops = ["freq"]
_field_ops = ["days", "seconds", "microseconds", "nanoseconds"]
_datetimelike_ops = _field_ops + _object_ops + _bool_ops
_datetimelike_methods = [
"to_pytimedelta",
"total_seconds",
"round",
"floor",
"ceil",
]
# Note: ndim must be defined to ensure NaT.__richcmp__(TimedeltaArray)
# operates pointwise.
def _box_func(self, x) -> Union[Timedelta, NaTType]:
return Timedelta(x, unit="ns")
@property
def dtype(self) -> np.dtype:
"""
The dtype for the TimedeltaArray.
.. warning::
A future version of pandas will change dtype to be an instance
of a :class:`pandas.api.extensions.ExtensionDtype` subclass,
not a ``numpy.dtype``.
Returns
-------
numpy.dtype
"""
return TD64NS_DTYPE
# ----------------------------------------------------------------
# Constructors
def __init__(self, values, dtype=TD64NS_DTYPE, freq=lib.no_default, copy=False):
values = extract_array(values)
inferred_freq = getattr(values, "_freq", None)
explicit_none = freq is None
freq = freq if freq is not lib.no_default else None
if isinstance(values, type(self)):
if explicit_none:
# dont inherit from values
pass
elif freq is None:
freq = values.freq
elif freq and values.freq:
freq = to_offset(freq)
freq, _ = dtl.validate_inferred_freq(freq, values.freq, False)
values = values._data
if not isinstance(values, np.ndarray):
msg = (
f"Unexpected type '{type(values).__name__}'. 'values' must be a "
"TimedeltaArray ndarray, or Series or Index containing one of those."
)
raise ValueError(msg)
if values.ndim not in [1, 2]:
raise ValueError("Only 1-dimensional input arrays are supported.")
if values.dtype == "i8":
# for compat with datetime/timedelta/period shared methods,
# we can sometimes get here with int64 values. These represent
# nanosecond UTC (or tz-naive) unix timestamps
values = values.view(TD64NS_DTYPE)
_validate_td64_dtype(values.dtype)
dtype = _validate_td64_dtype(dtype)
if freq == "infer":
msg = (
"Frequency inference not allowed in TimedeltaArray.__init__. "
"Use 'pd.array()' instead."
)
raise ValueError(msg)
if copy:
values = values.copy()
if freq:
freq = to_offset(freq)
self._data = values
self._dtype = dtype
self._freq = freq
if inferred_freq is None and freq is not None:
type(self)._validate_frequency(self, freq)
@classmethod
def _simple_new(
cls, values, freq: Optional[BaseOffset] = None, dtype=TD64NS_DTYPE
) -> "TimedeltaArray":
assert dtype == TD64NS_DTYPE, dtype
assert isinstance(values, np.ndarray), type(values)
if values.dtype != TD64NS_DTYPE:
assert values.dtype == "i8"
values = values.view(TD64NS_DTYPE)
result = object.__new__(cls)
result._data = values
result._freq = to_offset(freq)
result._dtype = TD64NS_DTYPE
return result
@classmethod
def _from_sequence(
cls, data, *, dtype=TD64NS_DTYPE, copy: bool = False
) -> "TimedeltaArray":
if dtype:
_validate_td64_dtype(dtype)
data, inferred_freq = sequence_to_td64ns(data, copy=copy, unit=None)
freq, _ = dtl.validate_inferred_freq(None, inferred_freq, False)
return cls._simple_new(data, freq=freq)
@classmethod
def _from_sequence_not_strict(
cls,
data,
dtype=TD64NS_DTYPE,
copy: bool = False,
freq=lib.no_default,
unit=None,
) -> "TimedeltaArray":
if dtype:
_validate_td64_dtype(dtype)
explicit_none = freq is None
freq = freq if freq is not lib.no_default else None
freq, freq_infer = dtl.maybe_infer_freq(freq)
data, inferred_freq = sequence_to_td64ns(data, copy=copy, unit=unit)
freq, freq_infer = dtl.validate_inferred_freq(freq, inferred_freq, freq_infer)
if explicit_none:
freq = None
result = cls._simple_new(data, freq=freq)
if inferred_freq is None and freq is not None:
# this condition precludes `freq_infer`
cls._validate_frequency(result, freq)
elif freq_infer:
# Set _freq directly to bypass duplicative _validate_frequency
# check.
result._freq = to_offset(result.inferred_freq)
return result
@classmethod
def _generate_range(cls, start, end, periods, freq, closed=None):
periods = dtl.validate_periods(periods)
if freq is None and any(x is None for x in [periods, start, end]):
raise ValueError("Must provide freq argument if no data is supplied")
if com.count_not_none(start, end, periods, freq) != 3:
raise ValueError(
"Of the four parameters: start, end, periods, "
"and freq, exactly three must be specified"
)
if start is not None:
start = Timedelta(start)
if end is not None:
end = Timedelta(end)
left_closed, right_closed = dtl.validate_endpoints(closed)
if freq is not None:
index = generate_regular_range(start, end, periods, freq)
else:
index = np.linspace(start.value, end.value, periods).astype("i8")
if not left_closed:
index = index[1:]
if not right_closed:
index = index[:-1]
return cls._simple_new(index, freq=freq)
# ----------------------------------------------------------------
# DatetimeLike Interface
def _unbox_scalar(self, value, setitem: bool = False) -> np.timedelta64:
if not isinstance(value, self._scalar_type) and value is not NaT:
raise ValueError("'value' should be a Timedelta.")
self._check_compatible_with(value, setitem=setitem)
return np.timedelta64(value.value, "ns")
def _scalar_from_string(self, value):
return Timedelta(value)
def _check_compatible_with(self, other, setitem: bool = False):
# we don't have anything to validate.
pass
# ----------------------------------------------------------------
# Array-Like / EA-Interface Methods
def astype(self, dtype, copy: bool = True):
# We handle
# --> timedelta64[ns]
# --> timedelta64
# DatetimeLikeArrayMixin super call handles other cases
dtype = pandas_dtype(dtype)
if is_timedelta64_dtype(dtype) and not is_timedelta64_ns_dtype(dtype):
# by pandas convention, converting to non-nano timedelta64
# returns an int64-dtyped array with ints representing multiples
# of the desired timedelta unit. This is essentially division
if self._hasnans:
# avoid double-copying
result = self._data.astype(dtype, copy=False)
return self._maybe_mask_results(
result, fill_value=None, convert="float64"
)
result = self._data.astype(dtype, copy=copy)
return result.astype("i8")
elif is_timedelta64_ns_dtype(dtype):
if copy:
return self.copy()
return self
return dtl.DatetimeLikeArrayMixin.astype(self, dtype, copy=copy)
def __iter__(self):
if self.ndim > 1:
for i in range(len(self)):
yield self[i]
else:
# convert in chunks of 10k for efficiency
data = self.asi8
length = len(self)
chunksize = 10000
chunks = int(length / chunksize) + 1
for i in range(chunks):
start_i = i * chunksize
end_i = min((i + 1) * chunksize, length)
converted = ints_to_pytimedelta(data[start_i:end_i], box=True)
yield from converted
# ----------------------------------------------------------------
# Reductions
def sum(
self,
*,
axis=None,
dtype=None,
out=None,
keepdims: bool = False,
initial=None,
skipna: bool = True,
min_count: int = 0,
):
nv.validate_sum(
(), {"dtype": dtype, "out": out, "keepdims": keepdims, "initial": initial}
)
result = nanops.nansum(
self._ndarray, axis=axis, skipna=skipna, min_count=min_count
)
return self._wrap_reduction_result(axis, result)
def std(
self,
*,
axis=None,
dtype=None,
out=None,
ddof: int = 1,
keepdims: bool = False,
skipna: bool = True,
):
nv.validate_stat_ddof_func(
(), {"dtype": dtype, "out": out, "keepdims": keepdims}, fname="std"
)
result = nanops.nanstd(self._ndarray, axis=axis, skipna=skipna, ddof=ddof)
if axis is None or self.ndim == 1:
return self._box_func(result)
return self._from_backing_data(result)
# ----------------------------------------------------------------
# Rendering Methods
def _formatter(self, boxed=False):
from pandas.io.formats.format import get_format_timedelta64
return get_format_timedelta64(self, box=True)
def _format_native_types(self, na_rep="NaT", date_format=None, **kwargs):
from pandas.io.formats.format import get_format_timedelta64
formatter = get_format_timedelta64(self._data, na_rep)
return np.array([formatter(x) for x in self._data.ravel()]).reshape(self.shape)
# ----------------------------------------------------------------
# Arithmetic Methods
def _add_offset(self, other):
assert not isinstance(other, Tick)
raise TypeError(
f"cannot add the type {type(other).__name__} to a {type(self).__name__}"
)
def _add_period(self, other: Period):
"""
Add a Period object.
"""
# We will wrap in a PeriodArray and defer to the reversed operation
from .period import PeriodArray
i8vals = np.broadcast_to(other.ordinal, self.shape)
oth = PeriodArray(i8vals, freq=other.freq)
return oth + self
def _add_datetime_arraylike(self, other):
"""
Add DatetimeArray/Index or ndarray[datetime64] to TimedeltaArray.
"""
if isinstance(other, np.ndarray):
# At this point we have already checked that dtype is datetime64
from pandas.core.arrays import DatetimeArray
other = DatetimeArray(other)
# defer to implementation in DatetimeArray
return other + self
def _add_datetimelike_scalar(self, other):
# adding a timedeltaindex to a datetimelike
from pandas.core.arrays import DatetimeArray
assert other is not NaT
other = Timestamp(other)
if other is NaT:
# In this case we specifically interpret NaT as a datetime, not
# the timedelta interpretation we would get by returning self + NaT
result = self.asi8.view("m8[ms]") + NaT.to_datetime64()
return DatetimeArray(result)
i8 = self.asi8
result = checked_add_with_arr(i8, other.value, arr_mask=self._isnan)
result = self._maybe_mask_results(result)
dtype = DatetimeTZDtype(tz=other.tz) if other.tz else DT64NS_DTYPE
return DatetimeArray(result, dtype=dtype, freq=self.freq)
def _addsub_object_array(self, other, op):
# Add or subtract Array-like of objects
try:
# TimedeltaIndex can only operate with a subset of DateOffset
# subclasses. Incompatible classes will raise AttributeError,
# which we re-raise as TypeError
return super()._addsub_object_array(other, op)
except AttributeError as err:
raise TypeError(
f"Cannot add/subtract non-tick DateOffset to {type(self).__name__}"
) from err
@unpack_zerodim_and_defer("__mul__")
def __mul__(self, other) -> "TimedeltaArray":
if is_scalar(other):
# numpy will accept float and int, raise TypeError for others
result = self._data * other
freq = None
if self.freq is not None and not isna(other):
freq = self.freq * other
return type(self)(result, freq=freq)
if not hasattr(other, "dtype"):
# list, tuple
other = np.array(other)
if len(other) != len(self) and not is_timedelta64_dtype(other.dtype):
# Exclude timedelta64 here so we correctly raise TypeError
# for that instead of ValueError
raise ValueError("Cannot multiply with unequal lengths")
if is_object_dtype(other.dtype):
# this multiplication will succeed only if all elements of other
# are int or float scalars, so we will end up with
# timedelta64[ns]-dtyped result
result = [self[n] * other[n] for n in range(len(self))]
result = np.array(result)
return type(self)(result)
# numpy will accept float or int dtype, raise TypeError for others
result = self._data * other
return type(self)(result)
__rmul__ = __mul__
@unpack_zerodim_and_defer("__truediv__")
def __truediv__(self, other):
# timedelta / X is well-defined for timedelta-like or numeric X
if isinstance(other, self._recognized_scalars):
other = Timedelta(other)
if other is NaT:
# specifically timedelta64-NaT
result = np.empty(self.shape, dtype=np.float64)
result.fill(np.nan)
return result
# otherwise, dispatch to Timedelta implementation
return self._data / other
elif lib.is_scalar(other):
# assume it is numeric
result = self._data / other
freq = None
if self.freq is not None:
# Tick division is not implemented, so operate on Timedelta
freq = self.freq.delta / other
return type(self)(result, freq=freq)
if not hasattr(other, "dtype"):
# e.g. list, tuple
other = np.array(other)
if len(other) != len(self):
raise ValueError("Cannot divide vectors with unequal lengths")
elif is_timedelta64_dtype(other.dtype):
# let numpy handle it
return self._data / other
elif is_object_dtype(other.dtype):
# We operate on raveled arrays to avoid problems in inference
# on NaT
srav = self.ravel()
orav = other.ravel()
result = [srav[n] / orav[n] for n in range(len(srav))]
result = np.array(result).reshape(self.shape)
# We need to do dtype inference in order to keep DataFrame ops
# behavior consistent with Series behavior
inferred = lib.infer_dtype(result)
if inferred == "timedelta":
flat = result.ravel()
result = type(self)._from_sequence(flat).reshape(result.shape)
elif inferred == "floating":
result = result.astype(float)
return result
else:
result = self._data / other
return type(self)(result)
@unpack_zerodim_and_defer("__rtruediv__")
def __rtruediv__(self, other):
# X / timedelta is defined only for timedelta-like X
if isinstance(other, self._recognized_scalars):
other = Timedelta(other)
if other is NaT:
# specifically timedelta64-NaT
result = np.empty(self.shape, dtype=np.float64)
result.fill(np.nan)
return result
# otherwise, dispatch to Timedelta implementation
return other / self._data
elif lib.is_scalar(other):
raise TypeError(
f"Cannot divide {type(other).__name__} by {type(self).__name__}"
)
if not hasattr(other, "dtype"):
# e.g. list, tuple
other = np.array(other)
if len(other) != len(self):
raise ValueError("Cannot divide vectors with unequal lengths")
elif is_timedelta64_dtype(other.dtype):
# let numpy handle it
return other / self._data
elif is_object_dtype(other.dtype):
# Note: unlike in __truediv__, we do not _need_ to do type
# inference on the result. It does not raise, a numeric array
# is returned. GH#23829
result = [other[n] / self[n] for n in range(len(self))]
return np.array(result)
else:
raise TypeError(
f"Cannot divide {other.dtype} data by {type(self).__name__}"
)
@unpack_zerodim_and_defer("__floordiv__")
def __floordiv__(self, other):
if is_scalar(other):
if isinstance(other, self._recognized_scalars):
other = Timedelta(other)
if other is NaT:
# treat this specifically as timedelta-NaT
result = np.empty(self.shape, dtype=np.float64)
result.fill(np.nan)
return result
# dispatch to Timedelta implementation
result = other.__rfloordiv__(self._data)
return result
# at this point we should only have numeric scalars; anything
# else will raise
result = self.asi8 // other
np.putmask(result, self._isnan, iNaT)
freq = None
if self.freq is not None:
# Note: freq gets division, not floor-division
freq = self.freq / other
if freq.nanos == 0 and self.freq.nanos != 0:
# e.g. if self.freq is Nano(1) then dividing by 2
# rounds down to zero
freq = None
return type(self)(result.view("m8[ns]"), freq=freq)
if not hasattr(other, "dtype"):
# list, tuple
other = np.array(other)
if len(other) != len(self):
raise ValueError("Cannot divide with unequal lengths")
elif is_timedelta64_dtype(other.dtype):
other = type(self)(other)
# numpy timedelta64 does not natively support floordiv, so operate
# on the i8 values
result = self.asi8 // other.asi8
mask = self._isnan | other._isnan
if mask.any():
result = result.astype(np.float64)
np.putmask(result, mask, np.nan)
return result
elif is_object_dtype(other.dtype):
result = [self[n] // other[n] for n in range(len(self))]
result = np.array(result)
if lib.infer_dtype(result, skipna=False) == "timedelta":
result, _ = sequence_to_td64ns(result)
return type(self)(result)
return result
elif is_integer_dtype(other.dtype) or is_float_dtype(other.dtype):
result = self._data // other
return type(self)(result)
else:
dtype = getattr(other, "dtype", type(other).__name__)
raise TypeError(f"Cannot divide {dtype} by {type(self).__name__}")
@unpack_zerodim_and_defer("__rfloordiv__")
def __rfloordiv__(self, other):
if is_scalar(other):
if isinstance(other, self._recognized_scalars):
other = Timedelta(other)
if other is NaT:
# treat this specifically as timedelta-NaT
result = np.empty(self.shape, dtype=np.float64)
result.fill(np.nan)
return result
# dispatch to Timedelta implementation
result = other.__floordiv__(self._data)
return result
raise TypeError(
f"Cannot divide {type(other).__name__} by {type(self).__name__}"
)
if not hasattr(other, "dtype"):
# list, tuple
other = np.array(other)
if len(other) != len(self):
raise ValueError("Cannot divide with unequal lengths")
elif is_timedelta64_dtype(other.dtype):
other = type(self)(other)
# numpy timedelta64 does not natively support floordiv, so operate
# on the i8 values
result = other.asi8 // self.asi8
mask = self._isnan | other._isnan
if mask.any():
result = result.astype(np.float64)
np.putmask(result, mask, np.nan)
return result
elif is_object_dtype(other.dtype):
result = [other[n] // self[n] for n in range(len(self))]
result = np.array(result)
return result
else:
dtype = getattr(other, "dtype", type(other).__name__)
raise TypeError(f"Cannot divide {dtype} by {type(self).__name__}")
@unpack_zerodim_and_defer("__mod__")
def __mod__(self, other):
# Note: This is a naive implementation, can likely be optimized
if isinstance(other, self._recognized_scalars):
other = Timedelta(other)
return self - (self // other) * other
@unpack_zerodim_and_defer("__rmod__")
def __rmod__(self, other):
# Note: This is a naive implementation, can likely be optimized
if isinstance(other, self._recognized_scalars):
other = Timedelta(other)
return other - (other // self) * self
@unpack_zerodim_and_defer("__divmod__")
def __divmod__(self, other):
# Note: This is a naive implementation, can likely be optimized
if isinstance(other, self._recognized_scalars):
other = Timedelta(other)
res1 = self // other
res2 = self - res1 * other
return res1, res2
@unpack_zerodim_and_defer("__rdivmod__")
def __rdivmod__(self, other):
# Note: This is a naive implementation, can likely be optimized
if isinstance(other, self._recognized_scalars):
other = Timedelta(other)
res1 = other // self
res2 = other - res1 * self
return res1, res2
def __neg__(self) -> "TimedeltaArray":
if self.freq is not None:
return type(self)(-self._data, freq=-self.freq)
return type(self)(-self._data)
def __pos__(self) -> "TimedeltaArray":
return type(self)(self._data, freq=self.freq)
def __abs__(self) -> "TimedeltaArray":
# Note: freq is not preserved
return type(self)(np.abs(self._data))
# ----------------------------------------------------------------
# Conversion Methods - Vectorized analogues of Timedelta methods
def total_seconds(self) -> np.ndarray:
"""
Return total duration of each element expressed in seconds.
This method is available directly on TimedeltaArray, TimedeltaIndex
and on Series containing timedelta values under the ``.dt`` namespace.
Returns
-------
seconds : [ndarray, Float64Index, Series]
When the calling object is a TimedeltaArray, the return type
is ndarray. When the calling object is a TimedeltaIndex,
the return type is a Float64Index. When the calling object
is a Series, the return type is Series of type `float64` whose
index is the same as the original.
See Also
--------
datetime.timedelta.total_seconds : Standard library version
of this method.
TimedeltaIndex.components : Return a DataFrame with components of
each Timedelta.
Examples
--------
**Series**
>>> s = pd.Series(pd.to_timedelta(np.arange(5), unit='d'))
>>> s
0 0 days
1 1 days
2 2 days
3 3 days
4 4 days
dtype: timedelta64[ns]
>>> s.dt.total_seconds()
0 0.0
1 86400.0
2 172800.0
3 259200.0
4 345600.0
dtype: float64
**TimedeltaIndex**
>>> idx = pd.to_timedelta(np.arange(5), unit='d')
>>> idx
TimedeltaIndex(['0 days', '1 days', '2 days', '3 days', '4 days'],
dtype='timedelta64[ns]', freq=None)
>>> idx.total_seconds()
Float64Index([0.0, 86400.0, 172800.0, 259200.00000000003, 345600.0],
dtype='float64')
"""
return self._maybe_mask_results(1e-9 * self.asi8, fill_value=None)
def to_pytimedelta(self) -> np.ndarray:
"""
Return Timedelta Array/Index as object ndarray of datetime.timedelta
objects.
Returns
-------
datetimes : ndarray
"""
return tslibs.ints_to_pytimedelta(self.asi8)
days = _field_accessor("days", "days", "Number of days for each element.")
seconds = _field_accessor(
"seconds",
"seconds",
"Number of seconds (>= 0 and less than 1 day) for each element.",
)
microseconds = _field_accessor(
"microseconds",
"microseconds",
"Number of microseconds (>= 0 and less than 1 second) for each element.",
)
nanoseconds = _field_accessor(
"nanoseconds",
"nanoseconds",
"Number of nanoseconds (>= 0 and less than 1 microsecond) for each element.",
)
@property
def components(self):
"""
Return a dataframe of the components (days, hours, minutes,
seconds, milliseconds, microseconds, nanoseconds) of the Timedeltas.
Returns
-------
a DataFrame
"""
from pandas import DataFrame
columns = [
"days",
"hours",
"minutes",
"seconds",
"milliseconds",
"microseconds",
"nanoseconds",
]
hasnans = self._hasnans
if hasnans:
def f(x):
if isna(x):
return [np.nan] * len(columns)
return x.components
else:
def f(x):
return x.components
result = DataFrame([f(x) for x in self], columns=columns)
if not hasnans:
result = result.astype("int64")
return result
# ---------------------------------------------------------------------
# Constructor Helpers
def sequence_to_td64ns(data, copy=False, unit=None, errors="raise"):
"""
Parameters
----------
data : list-like
copy : bool, default False
unit : str, optional
The timedelta unit to treat integers as multiples of. For numeric
data this defaults to ``'ns'``.
Must be un-specified if the data contains a str and ``errors=="raise"``.
errors : {"raise", "coerce", "ignore"}, default "raise"
How to handle elements that cannot be converted to timedelta64[ns].
See ``pandas.to_timedelta`` for details.
Returns
-------
converted : numpy.ndarray
The sequence converted to a numpy array with dtype ``timedelta64[ns]``.
inferred_freq : Tick or None
The inferred frequency of the sequence.
Raises
------
ValueError : Data cannot be converted to timedelta64[ns].
Notes
-----
Unlike `pandas.to_timedelta`, if setting ``errors=ignore`` will not cause
errors to be ignored; they are caught and subsequently ignored at a
higher level.
"""
inferred_freq = None
if unit is not None:
unit = parse_timedelta_unit(unit)
# Unwrap whatever we have into a np.ndarray
if not hasattr(data, "dtype"):
# e.g. list, tuple
if np.ndim(data) == 0:
# i.e. generator
data = list(data)
data = np.array(data, copy=False)
elif isinstance(data, ABCSeries):
data = data._values
elif isinstance(data, (ABCTimedeltaIndex, TimedeltaArray)):
inferred_freq = data.freq
data = data._data
elif isinstance(data, IntegerArray):
data = data.to_numpy("int64", na_value=tslibs.iNaT)
elif is_categorical_dtype(data.dtype):
data = data.categories.take(data.codes, fill_value=NaT)._values
copy = False
# Convert whatever we have into timedelta64[ns] dtype
if is_object_dtype(data.dtype) or is_string_dtype(data.dtype):
# no need to make a copy, need to convert if string-dtyped
data = objects_to_td64ns(data, unit=unit, errors=errors)
copy = False
elif is_integer_dtype(data.dtype):
# treat as multiples of the given unit
data, copy_made = ints_to_td64ns(data, unit=unit)
copy = copy and not copy_made
elif is_float_dtype(data.dtype):
# cast the unit, multiply base/frac separately
# to avoid precision issues from float -> int
mask = np.isnan(data)
m, p = precision_from_unit(unit or "ns")
base = data.astype(np.int64)
frac = data - base
if p:
frac = np.round(frac, p)
data = (base * m + (frac * m).astype(np.int64)).view("timedelta64[ns]")
data[mask] = iNaT
copy = False
elif is_timedelta64_dtype(data.dtype):
if data.dtype != TD64NS_DTYPE:
# non-nano unit
# TODO: watch out for overflows
data = data.astype(TD64NS_DTYPE)
copy = False
else:
# This includes datetime64-dtype, see GH#23539, GH#29794
raise TypeError(f"dtype {data.dtype} cannot be converted to timedelta64[ns]")
data = np.array(data, copy=copy)
assert data.dtype == "m8[ns]", data
return data, inferred_freq
def ints_to_td64ns(data, unit="ns"):
"""
Convert an ndarray with integer-dtype to timedelta64[ns] dtype, treating
the integers as multiples of the given timedelta unit.
Parameters
----------
data : numpy.ndarray with integer-dtype
unit : str, default "ns"
The timedelta unit to treat integers as multiples of.
Returns
-------
numpy.ndarray : timedelta64[ns] array converted from data
bool : whether a copy was made
"""
copy_made = False
unit = unit if unit is not None else "ns"
if data.dtype != np.int64:
# converting to int64 makes a copy, so we can avoid
# re-copying later
data = data.astype(np.int64)
copy_made = True
if unit != "ns":
dtype_str = f"timedelta64[{unit}]"
data = data.view(dtype_str)
# TODO: watch out for overflows when converting from lower-resolution
data = data.astype("timedelta64[ns]")
# the astype conversion makes a copy, so we can avoid re-copying later
copy_made = True
else:
data = data.view("timedelta64[ns]")
return data, copy_made
def objects_to_td64ns(data, unit=None, errors="raise"):
"""
Convert a object-dtyped or string-dtyped array into an
timedelta64[ns]-dtyped array.
Parameters
----------
data : ndarray or Index
unit : str, default "ns"
The timedelta unit to treat integers as multiples of.
Must not be specified if the data contains a str.
errors : {"raise", "coerce", "ignore"}, default "raise"
How to handle elements that cannot be converted to timedelta64[ns].
See ``pandas.to_timedelta`` for details.
Returns
-------
numpy.ndarray : timedelta64[ns] array converted from data
Raises
------
ValueError : Data cannot be converted to timedelta64[ns].
Notes
-----
Unlike `pandas.to_timedelta`, if setting `errors=ignore` will not cause
errors to be ignored; they are caught and subsequently ignored at a
higher level.
"""
# coerce Index to np.ndarray, converting string-dtype if necessary
values = np.array(data, dtype=np.object_, copy=False)
result = array_to_timedelta64(values, unit=unit, errors=errors)
return result.view("timedelta64[ns]")
def _validate_td64_dtype(dtype):
dtype = pandas_dtype(dtype)
if is_dtype_equal(dtype, np.dtype("timedelta64")):
# no precision disallowed GH#24806
msg = (
"Passing in 'timedelta' dtype with no precision is not allowed. "
"Please pass in 'timedelta64[ns]' instead."
)
raise ValueError(msg)
if not is_dtype_equal(dtype, TD64NS_DTYPE):
raise ValueError(f"dtype {dtype} cannot be converted to timedelta64[ns]")
return dtype