def sequence_to_td64ns(data, copy=False, unit="ns", errors="raise"):
"""
Parameters
----------
array : list-like
copy : bool, default False
unit : str, default "ns"
The timedelta unit to treat integers as multiples of.
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
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
# 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/frace separately
# to avoid precision issues from float -> int
mask = np.isnan(data)
m, p = precision_from_unit(unit)
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 != _TD_DTYPE:
# non-nano unit
# TODO: watch out for overflows
data = data.astype(_TD_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 sequence_to_td64ns(data, copy=False, unit="ns", errors="raise"):
"""
Parameters
----------
array : list-like
copy : bool, default False
unit : str, default "ns"
The timedelta unit to treat integers as multiples of.
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
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
# 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/frace separately
# to avoid precision issues from float -> int
mask = np.isnan(data)
m, p = precision_from_unit(unit)
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 != _TD_DTYPE:
# non-nano unit
# TODO: watch out for overflows
data = data.astype(_TD_DTYPE)
copy = False
elif is_datetime64_dtype(data):
# GH#23539
warnings.warn("Passing datetime64-dtype data to TimedeltaIndex is "
"deprecated, will raise a TypeError in a future "
"version",
FutureWarning, stacklevel=4)
data = ensure_int64(data).view(_TD_DTYPE)
else:
raise TypeError("dtype {dtype} cannot be converted to timedelta64[ns]"
.format(dtype=data.dtype))
data = np.array(data, copy=copy)
if data.ndim != 1:
raise ValueError("Only 1-dimensional input arrays are supported.")
assert data.dtype == 'm8[ns]', data
return data, inferred_freq
