Inzynierka/Lib/site-packages/pandas/core/indexes/datetimes.py
2023-06-02 12:51:02 +02:00

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from __future__ import annotations
import datetime as dt
import operator
from typing import (
TYPE_CHECKING,
Hashable,
)
import warnings
import numpy as np
import pytz
from pandas._libs import (
NaT,
Period,
Timestamp,
index as libindex,
lib,
)
from pandas._libs.tslibs import (
Resolution,
periods_per_day,
timezones,
to_offset,
)
from pandas._libs.tslibs.offsets import prefix_mapping
from pandas._typing import (
Dtype,
DtypeObj,
Frequency,
IntervalClosedType,
TimeAmbiguous,
TimeNonexistent,
npt,
)
from pandas.util._decorators import (
cache_readonly,
doc,
)
from pandas.core.dtypes.common import (
is_datetime64_dtype,
is_datetime64tz_dtype,
is_scalar,
)
from pandas.core.dtypes.generic import ABCSeries
from pandas.core.dtypes.missing import is_valid_na_for_dtype
from pandas.core.arrays.datetimes import (
DatetimeArray,
tz_to_dtype,
)
import pandas.core.common as com
from pandas.core.indexes.base import (
Index,
maybe_extract_name,
)
from pandas.core.indexes.datetimelike import DatetimeTimedeltaMixin
from pandas.core.indexes.extension import inherit_names
from pandas.core.tools.times import to_time
if TYPE_CHECKING:
from pandas.core.api import (
DataFrame,
PeriodIndex,
)
def _new_DatetimeIndex(cls, d):
"""
This is called upon unpickling, rather than the default which doesn't
have arguments and breaks __new__
"""
if "data" in d and not isinstance(d["data"], DatetimeIndex):
# Avoid need to verify integrity by calling simple_new directly
data = d.pop("data")
if not isinstance(data, DatetimeArray):
# For backward compat with older pickles, we may need to construct
# a DatetimeArray to adapt to the newer _simple_new signature
tz = d.pop("tz")
freq = d.pop("freq")
dta = DatetimeArray._simple_new(data, dtype=tz_to_dtype(tz), freq=freq)
else:
dta = data
for key in ["tz", "freq"]:
# These are already stored in our DatetimeArray; if they are
# also in the pickle and don't match, we have a problem.
if key in d:
assert d[key] == getattr(dta, key)
d.pop(key)
result = cls._simple_new(dta, **d)
else:
with warnings.catch_warnings():
# TODO: If we knew what was going in to **d, we might be able to
# go through _simple_new instead
warnings.simplefilter("ignore")
result = cls.__new__(cls, **d)
return result
@inherit_names(
DatetimeArray._field_ops
+ [
method
for method in DatetimeArray._datetimelike_methods
if method not in ("tz_localize", "tz_convert", "strftime")
],
DatetimeArray,
wrap=True,
)
@inherit_names(["is_normalized"], DatetimeArray, cache=True)
@inherit_names(
[
"tz",
"tzinfo",
"dtype",
"to_pydatetime",
"_format_native_types",
"date",
"time",
"timetz",
"std",
]
+ DatetimeArray._bool_ops,
DatetimeArray,
)
class DatetimeIndex(DatetimeTimedeltaMixin):
"""
Immutable ndarray-like of datetime64 data.
Represented internally as int64, and which can be boxed to Timestamp objects
that are subclasses of datetime and carry metadata.
.. versionchanged:: 2.0.0
The various numeric date/time attributes (:attr:`~DatetimeIndex.day`,
:attr:`~DatetimeIndex.month`, :attr:`~DatetimeIndex.year` etc.) now have dtype
``int32``. Previously they had dtype ``int64``.
Parameters
----------
data : array-like (1-dimensional)
Datetime-like data to construct index with.
freq : str or pandas offset object, optional
One of pandas date offset strings or corresponding objects. The string
'infer' can be passed in order to set the frequency of the index as the
inferred frequency upon creation.
tz : pytz.timezone or dateutil.tz.tzfile or datetime.tzinfo or str
Set the Timezone of the data.
normalize : bool, default False
Normalize start/end dates to midnight before generating date range.
closed : {'left', 'right'}, optional
Set whether to include `start` and `end` that are on the
boundary. The default includes boundary points on either end.
ambiguous : 'infer', bool-ndarray, 'NaT', default 'raise'
When clocks moved backward due to DST, ambiguous times may arise.
For example in Central European Time (UTC+01), when going from 03:00
DST to 02:00 non-DST, 02:30:00 local time occurs both at 00:30:00 UTC
and at 01:30:00 UTC. In such a situation, the `ambiguous` parameter
dictates how ambiguous times should be handled.
- 'infer' will attempt to infer fall dst-transition hours based on
order
- bool-ndarray where True signifies a DST time, False signifies a
non-DST time (note that this flag is only applicable for ambiguous
times)
- 'NaT' will return NaT where there are ambiguous times
- 'raise' will raise an AmbiguousTimeError if there are ambiguous times.
dayfirst : bool, default False
If True, parse dates in `data` with the day first order.
yearfirst : bool, default False
If True parse dates in `data` with the year first order.
dtype : numpy.dtype or DatetimeTZDtype or str, default None
Note that the only NumPy dtype allowed is datetime64[ns].
copy : bool, default False
Make a copy of input ndarray.
name : label, default None
Name to be stored in the index.
Attributes
----------
year
month
day
hour
minute
second
microsecond
nanosecond
date
time
timetz
dayofyear
day_of_year
weekofyear
week
dayofweek
day_of_week
weekday
quarter
tz
freq
freqstr
is_month_start
is_month_end
is_quarter_start
is_quarter_end
is_year_start
is_year_end
is_leap_year
inferred_freq
Methods
-------
normalize
strftime
snap
tz_convert
tz_localize
round
floor
ceil
to_period
to_pydatetime
to_series
to_frame
month_name
day_name
mean
std
See Also
--------
Index : The base pandas Index type.
TimedeltaIndex : Index of timedelta64 data.
PeriodIndex : Index of Period data.
to_datetime : Convert argument to datetime.
date_range : Create a fixed-frequency DatetimeIndex.
Notes
-----
To learn more about the frequency strings, please see `this link
<https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#offset-aliases>`__.
"""
_typ = "datetimeindex"
_data_cls = DatetimeArray
_supports_partial_string_indexing = True
@property
def _engine_type(self) -> type[libindex.DatetimeEngine]:
return libindex.DatetimeEngine
_data: DatetimeArray
tz: dt.tzinfo | None
# --------------------------------------------------------------------
# methods that dispatch to DatetimeArray and wrap result
@doc(DatetimeArray.strftime)
def strftime(self, date_format) -> Index:
arr = self._data.strftime(date_format)
return Index(arr, name=self.name, dtype=object)
@doc(DatetimeArray.tz_convert)
def tz_convert(self, tz) -> DatetimeIndex:
arr = self._data.tz_convert(tz)
return type(self)._simple_new(arr, name=self.name, refs=self._references)
@doc(DatetimeArray.tz_localize)
def tz_localize(
self,
tz,
ambiguous: TimeAmbiguous = "raise",
nonexistent: TimeNonexistent = "raise",
) -> DatetimeIndex:
arr = self._data.tz_localize(tz, ambiguous, nonexistent)
return type(self)._simple_new(arr, name=self.name)
@doc(DatetimeArray.to_period)
def to_period(self, freq=None) -> PeriodIndex:
from pandas.core.indexes.api import PeriodIndex
arr = self._data.to_period(freq)
return PeriodIndex._simple_new(arr, name=self.name)
@doc(DatetimeArray.to_julian_date)
def to_julian_date(self) -> Index:
arr = self._data.to_julian_date()
return Index._simple_new(arr, name=self.name)
@doc(DatetimeArray.isocalendar)
def isocalendar(self) -> DataFrame:
df = self._data.isocalendar()
return df.set_index(self)
@cache_readonly
def _resolution_obj(self) -> Resolution:
return self._data._resolution_obj
# --------------------------------------------------------------------
# Constructors
def __new__(
cls,
data=None,
freq: Frequency | lib.NoDefault = lib.no_default,
tz=lib.no_default,
normalize: bool = False,
closed=None,
ambiguous: TimeAmbiguous = "raise",
dayfirst: bool = False,
yearfirst: bool = False,
dtype: Dtype | None = None,
copy: bool = False,
name: Hashable = None,
) -> DatetimeIndex:
if is_scalar(data):
cls._raise_scalar_data_error(data)
# - Cases checked above all return/raise before reaching here - #
name = maybe_extract_name(name, data, cls)
if (
isinstance(data, DatetimeArray)
and freq is lib.no_default
and tz is lib.no_default
and dtype is None
):
# fastpath, similar logic in TimedeltaIndex.__new__;
# Note in this particular case we retain non-nano.
if copy:
data = data.copy()
return cls._simple_new(data, name=name)
dtarr = DatetimeArray._from_sequence_not_strict(
data,
dtype=dtype,
copy=copy,
tz=tz,
freq=freq,
dayfirst=dayfirst,
yearfirst=yearfirst,
ambiguous=ambiguous,
)
refs = None
if not copy and isinstance(data, (Index, ABCSeries)):
refs = data._references
subarr = cls._simple_new(dtarr, name=name, refs=refs)
return subarr
# --------------------------------------------------------------------
@cache_readonly
def _is_dates_only(self) -> bool:
"""
Return a boolean if we are only dates (and don't have a timezone)
Returns
-------
bool
"""
from pandas.io.formats.format import is_dates_only
# error: Argument 1 to "is_dates_only" has incompatible type
# "Union[ExtensionArray, ndarray]"; expected "Union[ndarray,
# DatetimeArray, Index, DatetimeIndex]"
return self.tz is None and is_dates_only(self._values) # type: ignore[arg-type]
def __reduce__(self):
d = {"data": self._data, "name": self.name}
return _new_DatetimeIndex, (type(self), d), None
def _is_comparable_dtype(self, dtype: DtypeObj) -> bool:
"""
Can we compare values of the given dtype to our own?
"""
if self.tz is not None:
# If we have tz, we can compare to tzaware
return is_datetime64tz_dtype(dtype)
# if we dont have tz, we can only compare to tznaive
return is_datetime64_dtype(dtype)
# --------------------------------------------------------------------
# Rendering Methods
@property
def _formatter_func(self):
from pandas.io.formats.format import get_format_datetime64
formatter = get_format_datetime64(is_dates_only_=self._is_dates_only)
return lambda x: f"'{formatter(x)}'"
# --------------------------------------------------------------------
# Set Operation Methods
def _can_range_setop(self, other) -> bool:
# GH 46702: If self or other have non-UTC tzs, DST transitions prevent
# range representation due to no singular step
if (
self.tz is not None
and not timezones.is_utc(self.tz)
and not timezones.is_fixed_offset(self.tz)
):
return False
if (
other.tz is not None
and not timezones.is_utc(other.tz)
and not timezones.is_fixed_offset(other.tz)
):
return False
return super()._can_range_setop(other)
# --------------------------------------------------------------------
def _get_time_micros(self) -> npt.NDArray[np.int64]:
"""
Return the number of microseconds since midnight.
Returns
-------
ndarray[int64_t]
"""
values = self._data._local_timestamps()
ppd = periods_per_day(self._data._creso)
frac = values % ppd
if self.unit == "ns":
micros = frac // 1000
elif self.unit == "us":
micros = frac
elif self.unit == "ms":
micros = frac * 1000
elif self.unit == "s":
micros = frac * 1_000_000
else: # pragma: no cover
raise NotImplementedError(self.unit)
micros[self._isnan] = -1
return micros
def snap(self, freq: Frequency = "S") -> DatetimeIndex:
"""
Snap time stamps to nearest occurring frequency.
Returns
-------
DatetimeIndex
"""
# Superdumb, punting on any optimizing
freq = to_offset(freq)
dta = self._data.copy()
for i, v in enumerate(self):
s = v
if not freq.is_on_offset(s):
t0 = freq.rollback(s)
t1 = freq.rollforward(s)
if abs(s - t0) < abs(t1 - s):
s = t0
else:
s = t1
dta[i] = s
return DatetimeIndex._simple_new(dta, name=self.name)
# --------------------------------------------------------------------
# Indexing Methods
def _parsed_string_to_bounds(self, reso: Resolution, parsed: dt.datetime):
"""
Calculate datetime bounds for parsed time string and its resolution.
Parameters
----------
reso : Resolution
Resolution provided by parsed string.
parsed : datetime
Datetime from parsed string.
Returns
-------
lower, upper: pd.Timestamp
"""
per = Period(parsed, freq=reso.attr_abbrev)
start, end = per.start_time, per.end_time
# GH 24076
# If an incoming date string contained a UTC offset, need to localize
# the parsed date to this offset first before aligning with the index's
# timezone
start = start.tz_localize(parsed.tzinfo)
end = end.tz_localize(parsed.tzinfo)
if parsed.tzinfo is not None:
if self.tz is None:
raise ValueError(
"The index must be timezone aware when indexing "
"with a date string with a UTC offset"
)
# The flipped case with parsed.tz is None and self.tz is not None
# is ruled out bc parsed and reso are produced by _parse_with_reso,
# which localizes parsed.
return start, end
def _parse_with_reso(self, label: str):
parsed, reso = super()._parse_with_reso(label)
parsed = Timestamp(parsed)
if self.tz is not None and parsed.tzinfo is None:
# we special-case timezone-naive strings and timezone-aware
# DatetimeIndex
# https://github.com/pandas-dev/pandas/pull/36148#issuecomment-687883081
parsed = parsed.tz_localize(self.tz)
return parsed, reso
def _disallow_mismatched_indexing(self, key) -> None:
"""
Check for mismatched-tzawareness indexing and re-raise as KeyError.
"""
# we get here with isinstance(key, self._data._recognized_scalars)
try:
# GH#36148
self._data._assert_tzawareness_compat(key)
except TypeError as err:
raise KeyError(key) from err
def get_loc(self, key):
"""
Get integer location for requested label
Returns
-------
loc : int
"""
self._check_indexing_error(key)
orig_key = key
if is_valid_na_for_dtype(key, self.dtype):
key = NaT
if isinstance(key, self._data._recognized_scalars):
# needed to localize naive datetimes
self._disallow_mismatched_indexing(key)
key = Timestamp(key)
elif isinstance(key, str):
try:
parsed, reso = self._parse_with_reso(key)
except (ValueError, pytz.NonExistentTimeError) as err:
raise KeyError(key) from err
self._disallow_mismatched_indexing(parsed)
if self._can_partial_date_slice(reso):
try:
return self._partial_date_slice(reso, parsed)
except KeyError as err:
raise KeyError(key) from err
key = parsed
elif isinstance(key, dt.timedelta):
# GH#20464
raise TypeError(
f"Cannot index {type(self).__name__} with {type(key).__name__}"
)
elif isinstance(key, dt.time):
return self.indexer_at_time(key)
else:
# unrecognized type
raise KeyError(key)
try:
return Index.get_loc(self, key)
except KeyError as err:
raise KeyError(orig_key) from err
@doc(DatetimeTimedeltaMixin._maybe_cast_slice_bound)
def _maybe_cast_slice_bound(self, label, side: str):
# GH#42855 handle date here instead of get_slice_bound
if isinstance(label, dt.date) and not isinstance(label, dt.datetime):
# Pandas supports slicing with dates, treated as datetimes at midnight.
# https://github.com/pandas-dev/pandas/issues/31501
label = Timestamp(label).to_pydatetime()
label = super()._maybe_cast_slice_bound(label, side)
self._data._assert_tzawareness_compat(label)
return Timestamp(label)
def slice_indexer(self, start=None, end=None, step=None):
"""
Return indexer for specified label slice.
Index.slice_indexer, customized to handle time slicing.
In addition to functionality provided by Index.slice_indexer, does the
following:
- if both `start` and `end` are instances of `datetime.time`, it
invokes `indexer_between_time`
- if `start` and `end` are both either string or None perform
value-based selection in non-monotonic cases.
"""
# For historical reasons DatetimeIndex supports slices between two
# instances of datetime.time as if it were applying a slice mask to
# an array of (self.hour, self.minute, self.seconds, self.microsecond).
if isinstance(start, dt.time) and isinstance(end, dt.time):
if step is not None and step != 1:
raise ValueError("Must have step size of 1 with time slices")
return self.indexer_between_time(start, end)
if isinstance(start, dt.time) or isinstance(end, dt.time):
raise KeyError("Cannot mix time and non-time slice keys")
def check_str_or_none(point) -> bool:
return point is not None and not isinstance(point, str)
# GH#33146 if start and end are combinations of str and None and Index is not
# monotonic, we can not use Index.slice_indexer because it does not honor the
# actual elements, is only searching for start and end
if (
check_str_or_none(start)
or check_str_or_none(end)
or self.is_monotonic_increasing
):
return Index.slice_indexer(self, start, end, step)
mask = np.array(True)
raise_mask = np.array(True)
if start is not None:
start_casted = self._maybe_cast_slice_bound(start, "left")
mask = start_casted <= self
raise_mask = start_casted == self
if end is not None:
end_casted = self._maybe_cast_slice_bound(end, "right")
mask = (self <= end_casted) & mask
raise_mask = (end_casted == self) | raise_mask
if not raise_mask.any():
raise KeyError(
"Value based partial slicing on non-monotonic DatetimeIndexes "
"with non-existing keys is not allowed.",
)
indexer = mask.nonzero()[0][::step]
if len(indexer) == len(self):
return slice(None)
else:
return indexer
# --------------------------------------------------------------------
@property
def inferred_type(self) -> str:
# b/c datetime is represented as microseconds since the epoch, make
# sure we can't have ambiguous indexing
return "datetime64"
def indexer_at_time(self, time, asof: bool = False) -> npt.NDArray[np.intp]:
"""
Return index locations of values at particular time of day.
Parameters
----------
time : datetime.time or str
Time passed in either as object (datetime.time) or as string in
appropriate format ("%H:%M", "%H%M", "%I:%M%p", "%I%M%p",
"%H:%M:%S", "%H%M%S", "%I:%M:%S%p", "%I%M%S%p").
Returns
-------
np.ndarray[np.intp]
See Also
--------
indexer_between_time : Get index locations of values between particular
times of day.
DataFrame.at_time : Select values at particular time of day.
"""
if asof:
raise NotImplementedError("'asof' argument is not supported")
if isinstance(time, str):
from dateutil.parser import parse
time = parse(time).time()
if time.tzinfo:
if self.tz is None:
raise ValueError("Index must be timezone aware.")
time_micros = self.tz_convert(time.tzinfo)._get_time_micros()
else:
time_micros = self._get_time_micros()
micros = _time_to_micros(time)
return (time_micros == micros).nonzero()[0]
def indexer_between_time(
self, start_time, end_time, include_start: bool = True, include_end: bool = True
) -> npt.NDArray[np.intp]:
"""
Return index locations of values between particular times of day.
Parameters
----------
start_time, end_time : datetime.time, str
Time passed either as object (datetime.time) or as string in
appropriate format ("%H:%M", "%H%M", "%I:%M%p", "%I%M%p",
"%H:%M:%S", "%H%M%S", "%I:%M:%S%p","%I%M%S%p").
include_start : bool, default True
include_end : bool, default True
Returns
-------
np.ndarray[np.intp]
See Also
--------
indexer_at_time : Get index locations of values at particular time of day.
DataFrame.between_time : Select values between particular times of day.
"""
start_time = to_time(start_time)
end_time = to_time(end_time)
time_micros = self._get_time_micros()
start_micros = _time_to_micros(start_time)
end_micros = _time_to_micros(end_time)
if include_start and include_end:
lop = rop = operator.le
elif include_start:
lop = operator.le
rop = operator.lt
elif include_end:
lop = operator.lt
rop = operator.le
else:
lop = rop = operator.lt
if start_time <= end_time:
join_op = operator.and_
else:
join_op = operator.or_
mask = join_op(lop(start_micros, time_micros), rop(time_micros, end_micros))
return mask.nonzero()[0]
def date_range(
start=None,
end=None,
periods=None,
freq=None,
tz=None,
normalize: bool = False,
name: Hashable = None,
inclusive: IntervalClosedType = "both",
*,
unit: str | None = None,
**kwargs,
) -> DatetimeIndex:
"""
Return a fixed frequency DatetimeIndex.
Returns the range of equally spaced time points (where the difference between any
two adjacent points is specified by the given frequency) such that they all
satisfy `start <[=] x <[=] end`, where the first one and the last one are, resp.,
the first and last time points in that range that fall on the boundary of ``freq``
(if given as a frequency string) or that are valid for ``freq`` (if given as a
:class:`pandas.tseries.offsets.DateOffset`). (If exactly one of ``start``,
``end``, or ``freq`` is *not* specified, this missing parameter can be computed
given ``periods``, the number of timesteps in the range. See the note below.)
Parameters
----------
start : str or datetime-like, optional
Left bound for generating dates.
end : str or datetime-like, optional
Right bound for generating dates.
periods : int, optional
Number of periods to generate.
freq : str, datetime.timedelta, or DateOffset, default 'D'
Frequency strings can have multiples, e.g. '5H'. See
:ref:`here <timeseries.offset_aliases>` for a list of
frequency aliases.
tz : str or tzinfo, optional
Time zone name for returning localized DatetimeIndex, for example
'Asia/Hong_Kong'. By default, the resulting DatetimeIndex is
timezone-naive unless timezone-aware datetime-likes are passed.
normalize : bool, default False
Normalize start/end dates to midnight before generating date range.
name : str, default None
Name of the resulting DatetimeIndex.
inclusive : {"both", "neither", "left", "right"}, default "both"
Include boundaries; Whether to set each bound as closed or open.
.. versionadded:: 1.4.0
unit : str, default None
Specify the desired resolution of the result.
.. versionadded:: 2.0.0
**kwargs
For compatibility. Has no effect on the result.
Returns
-------
DatetimeIndex
See Also
--------
DatetimeIndex : An immutable container for datetimes.
timedelta_range : Return a fixed frequency TimedeltaIndex.
period_range : Return a fixed frequency PeriodIndex.
interval_range : Return a fixed frequency IntervalIndex.
Notes
-----
Of the four parameters ``start``, ``end``, ``periods``, and ``freq``,
exactly three must be specified. If ``freq`` is omitted, the resulting
``DatetimeIndex`` will have ``periods`` linearly spaced elements between
``start`` and ``end`` (closed on both sides).
To learn more about the frequency strings, please see `this link
<https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#offset-aliases>`__.
Examples
--------
**Specifying the values**
The next four examples generate the same `DatetimeIndex`, but vary
the combination of `start`, `end` and `periods`.
Specify `start` and `end`, with the default daily frequency.
>>> pd.date_range(start='1/1/2018', end='1/08/2018')
DatetimeIndex(['2018-01-01', '2018-01-02', '2018-01-03', '2018-01-04',
'2018-01-05', '2018-01-06', '2018-01-07', '2018-01-08'],
dtype='datetime64[ns]', freq='D')
Specify timezone-aware `start` and `end`, with the default daily frequency.
>>> pd.date_range(
... start=pd.to_datetime("1/1/2018").tz_localize("Europe/Berlin"),
... end=pd.to_datetime("1/08/2018").tz_localize("Europe/Berlin"),
... )
DatetimeIndex(['2018-01-01 00:00:00+01:00', '2018-01-02 00:00:00+01:00',
'2018-01-03 00:00:00+01:00', '2018-01-04 00:00:00+01:00',
'2018-01-05 00:00:00+01:00', '2018-01-06 00:00:00+01:00',
'2018-01-07 00:00:00+01:00', '2018-01-08 00:00:00+01:00'],
dtype='datetime64[ns, Europe/Berlin]', freq='D')
Specify `start` and `periods`, the number of periods (days).
>>> pd.date_range(start='1/1/2018', periods=8)
DatetimeIndex(['2018-01-01', '2018-01-02', '2018-01-03', '2018-01-04',
'2018-01-05', '2018-01-06', '2018-01-07', '2018-01-08'],
dtype='datetime64[ns]', freq='D')
Specify `end` and `periods`, the number of periods (days).
>>> pd.date_range(end='1/1/2018', periods=8)
DatetimeIndex(['2017-12-25', '2017-12-26', '2017-12-27', '2017-12-28',
'2017-12-29', '2017-12-30', '2017-12-31', '2018-01-01'],
dtype='datetime64[ns]', freq='D')
Specify `start`, `end`, and `periods`; the frequency is generated
automatically (linearly spaced).
>>> pd.date_range(start='2018-04-24', end='2018-04-27', periods=3)
DatetimeIndex(['2018-04-24 00:00:00', '2018-04-25 12:00:00',
'2018-04-27 00:00:00'],
dtype='datetime64[ns]', freq=None)
**Other Parameters**
Changed the `freq` (frequency) to ``'M'`` (month end frequency).
>>> pd.date_range(start='1/1/2018', periods=5, freq='M')
DatetimeIndex(['2018-01-31', '2018-02-28', '2018-03-31', '2018-04-30',
'2018-05-31'],
dtype='datetime64[ns]', freq='M')
Multiples are allowed
>>> pd.date_range(start='1/1/2018', periods=5, freq='3M')
DatetimeIndex(['2018-01-31', '2018-04-30', '2018-07-31', '2018-10-31',
'2019-01-31'],
dtype='datetime64[ns]', freq='3M')
`freq` can also be specified as an Offset object.
>>> pd.date_range(start='1/1/2018', periods=5, freq=pd.offsets.MonthEnd(3))
DatetimeIndex(['2018-01-31', '2018-04-30', '2018-07-31', '2018-10-31',
'2019-01-31'],
dtype='datetime64[ns]', freq='3M')
Specify `tz` to set the timezone.
>>> pd.date_range(start='1/1/2018', periods=5, tz='Asia/Tokyo')
DatetimeIndex(['2018-01-01 00:00:00+09:00', '2018-01-02 00:00:00+09:00',
'2018-01-03 00:00:00+09:00', '2018-01-04 00:00:00+09:00',
'2018-01-05 00:00:00+09:00'],
dtype='datetime64[ns, Asia/Tokyo]', freq='D')
`inclusive` controls whether to include `start` and `end` that are on the
boundary. The default, "both", includes boundary points on either end.
>>> pd.date_range(start='2017-01-01', end='2017-01-04', inclusive="both")
DatetimeIndex(['2017-01-01', '2017-01-02', '2017-01-03', '2017-01-04'],
dtype='datetime64[ns]', freq='D')
Use ``inclusive='left'`` to exclude `end` if it falls on the boundary.
>>> pd.date_range(start='2017-01-01', end='2017-01-04', inclusive='left')
DatetimeIndex(['2017-01-01', '2017-01-02', '2017-01-03'],
dtype='datetime64[ns]', freq='D')
Use ``inclusive='right'`` to exclude `start` if it falls on the boundary, and
similarly ``inclusive='neither'`` will exclude both `start` and `end`.
>>> pd.date_range(start='2017-01-01', end='2017-01-04', inclusive='right')
DatetimeIndex(['2017-01-02', '2017-01-03', '2017-01-04'],
dtype='datetime64[ns]', freq='D')
**Specify a unit**
>>> pd.date_range(start="2017-01-01", periods=10, freq="100AS", unit="s")
DatetimeIndex(['2017-01-01', '2117-01-01', '2217-01-01', '2317-01-01',
'2417-01-01', '2517-01-01', '2617-01-01', '2717-01-01',
'2817-01-01', '2917-01-01'],
dtype='datetime64[s]', freq='100AS-JAN')
"""
if freq is None and com.any_none(periods, start, end):
freq = "D"
dtarr = DatetimeArray._generate_range(
start=start,
end=end,
periods=periods,
freq=freq,
tz=tz,
normalize=normalize,
inclusive=inclusive,
unit=unit,
**kwargs,
)
return DatetimeIndex._simple_new(dtarr, name=name)
def bdate_range(
start=None,
end=None,
periods: int | None = None,
freq: Frequency = "B",
tz=None,
normalize: bool = True,
name: Hashable = None,
weekmask=None,
holidays=None,
inclusive: IntervalClosedType = "both",
**kwargs,
) -> DatetimeIndex:
"""
Return a fixed frequency DatetimeIndex with business day as the default.
Parameters
----------
start : str or datetime-like, default None
Left bound for generating dates.
end : str or datetime-like, default None
Right bound for generating dates.
periods : int, default None
Number of periods to generate.
freq : str, Timedelta, datetime.timedelta, or DateOffset, default 'B'
Frequency strings can have multiples, e.g. '5H'. The default is
business daily ('B').
tz : str or None
Time zone name for returning localized DatetimeIndex, for example
Asia/Beijing.
normalize : bool, default False
Normalize start/end dates to midnight before generating date range.
name : str, default None
Name of the resulting DatetimeIndex.
weekmask : str or None, default None
Weekmask of valid business days, passed to ``numpy.busdaycalendar``,
only used when custom frequency strings are passed. The default
value None is equivalent to 'Mon Tue Wed Thu Fri'.
holidays : list-like or None, default None
Dates to exclude from the set of valid business days, passed to
``numpy.busdaycalendar``, only used when custom frequency strings
are passed.
inclusive : {"both", "neither", "left", "right"}, default "both"
Include boundaries; Whether to set each bound as closed or open.
.. versionadded:: 1.4.0
**kwargs
For compatibility. Has no effect on the result.
Returns
-------
DatetimeIndex
Notes
-----
Of the four parameters: ``start``, ``end``, ``periods``, and ``freq``,
exactly three must be specified. Specifying ``freq`` is a requirement
for ``bdate_range``. Use ``date_range`` if specifying ``freq`` is not
desired.
To learn more about the frequency strings, please see `this link
<https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#offset-aliases>`__.
Examples
--------
Note how the two weekend days are skipped in the result.
>>> pd.bdate_range(start='1/1/2018', end='1/08/2018')
DatetimeIndex(['2018-01-01', '2018-01-02', '2018-01-03', '2018-01-04',
'2018-01-05', '2018-01-08'],
dtype='datetime64[ns]', freq='B')
"""
if freq is None:
msg = "freq must be specified for bdate_range; use date_range instead"
raise TypeError(msg)
if isinstance(freq, str) and freq.startswith("C"):
try:
weekmask = weekmask or "Mon Tue Wed Thu Fri"
freq = prefix_mapping[freq](holidays=holidays, weekmask=weekmask)
except (KeyError, TypeError) as err:
msg = f"invalid custom frequency string: {freq}"
raise ValueError(msg) from err
elif holidays or weekmask:
msg = (
"a custom frequency string is required when holidays or "
f"weekmask are passed, got frequency {freq}"
)
raise ValueError(msg)
return date_range(
start=start,
end=end,
periods=periods,
freq=freq,
tz=tz,
normalize=normalize,
name=name,
inclusive=inclusive,
**kwargs,
)
def _time_to_micros(time_obj: dt.time) -> int:
seconds = time_obj.hour * 60 * 60 + 60 * time_obj.minute + time_obj.second
return 1_000_000 * seconds + time_obj.microsecond