from datetime import date, datetime, time, timedelta, tzinfo import operator from typing import TYPE_CHECKING, Optional, Tuple import warnings import numpy as np from pandas._libs import NaT, Period, Timestamp, index as libindex, lib from pandas._libs.tslibs import ( Resolution, ints_to_pydatetime, parsing, timezones, to_offset, ) from pandas._libs.tslibs.offsets import prefix_mapping from pandas._typing import DtypeObj from pandas.errors import InvalidIndexError from pandas.util._decorators import cache_readonly, doc from pandas.core.dtypes.common import ( DT64NS_DTYPE, is_datetime64_dtype, is_datetime64tz_dtype, is_scalar, ) from pandas.core.dtypes.missing import is_valid_nat_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, get_unanimous_names, 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 import DataFrame, Float64Index, PeriodIndex, TimedeltaIndex 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.pop(key) == getattr(dta, 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") ], DatetimeArray, wrap=True, ) @inherit_names(["is_normalized", "_resolution_obj"], DatetimeArray, cache=True) @inherit_names( [ "_bool_ops", "_object_ops", "_field_ops", "_datetimelike_ops", "_datetimelike_methods", "tz", "tzinfo", "dtype", "to_pydatetime", "_has_same_tz", "_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. Parameters ---------- data : array-like (1-dimensional), optional Optional 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_perioddelta 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 `__. """ _typ = "datetimeindex" _data_cls = DatetimeArray _engine_type = libindex.DatetimeEngine _supports_partial_string_indexing = True _comparables = ["name", "freqstr", "tz"] _attributes = ["name", "tz", "freq"] _is_numeric_dtype = False _data: DatetimeArray inferred_freq: Optional[str] tz: Optional[tzinfo] # -------------------------------------------------------------------- # 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) @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) @doc(DatetimeArray.tz_localize) def tz_localize( self, tz, ambiguous="raise", nonexistent="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_perioddelta) def to_perioddelta(self, freq) -> "TimedeltaIndex": from pandas.core.indexes.api import TimedeltaIndex arr = self._data.to_perioddelta(freq) return TimedeltaIndex._simple_new(arr, name=self.name) @doc(DatetimeArray.to_julian_date) def to_julian_date(self) -> "Float64Index": from pandas.core.indexes.api import Float64Index arr = self._data.to_julian_date() return Float64Index._simple_new(arr, name=self.name) @doc(DatetimeArray.isocalendar) def isocalendar(self) -> "DataFrame": df = self._data.isocalendar() return df.set_index(self) # -------------------------------------------------------------------- # Constructors def __new__( cls, data=None, freq=lib.no_default, tz=None, normalize=False, closed=None, ambiguous="raise", dayfirst=False, yearfirst=False, dtype=None, copy=False, name=None, ): if is_scalar(data): raise TypeError( f"{cls.__name__}() must be called with a " f"collection of some kind, {repr(data)} was passed" ) # - Cases checked above all return/raise before reaching here - # name = maybe_extract_name(name, data, cls) dtarr = DatetimeArray._from_sequence_not_strict( data, dtype=dtype, copy=copy, tz=tz, freq=freq, dayfirst=dayfirst, yearfirst=yearfirst, ambiguous=ambiguous, ) subarr = cls._simple_new(dtarr, name=name) 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 return self.tz is None and is_dates_only(self._values) def __reduce__(self): # we use a special reduce here because we need # to simply set the .tz (and not reinterpret it) d = {"data": self._data} d.update(self._get_attributes_dict()) return _new_DatetimeIndex, (type(self), d), None def _validate_fill_value(self, value): """ Convert value to be insertable to ndarray. """ return self._data._validate_setitem_value(value) 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 def _mpl_repr(self): # how to represent ourselves to matplotlib return ints_to_pydatetime(self.asi8, self.tz) @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 union_many(self, others): """ A bit of a hack to accelerate unioning a collection of indexes. """ this = self for other in others: if not isinstance(this, DatetimeIndex): this = Index.union(this, other) continue if not isinstance(other, DatetimeIndex): try: other = DatetimeIndex(other) except TypeError: pass this, other = this._maybe_utc_convert(other) if this._can_fast_union(other): this = this._fast_union(other) else: this = Index.union(this, other) res_name = get_unanimous_names(self, *others)[0] if this.name != res_name: return this.rename(res_name) return this def _maybe_utc_convert(self, other: Index) -> Tuple["DatetimeIndex", Index]: this = self if isinstance(other, DatetimeIndex): if self.tz is not None: if other.tz is None: raise TypeError("Cannot join tz-naive with tz-aware DatetimeIndex") elif other.tz is not None: raise TypeError("Cannot join tz-naive with tz-aware DatetimeIndex") if not timezones.tz_compare(self.tz, other.tz): this = self.tz_convert("UTC") other = other.tz_convert("UTC") return this, other # -------------------------------------------------------------------- def _get_time_micros(self): """ Return the number of microseconds since midnight. Returns ------- ndarray[int64_t] """ values = self._data._local_timestamps() nanos = values % (24 * 3600 * 1_000_000_000) micros = nanos // 1000 micros[self._isnan] = -1 return micros def to_series(self, keep_tz=lib.no_default, index=None, name=None): """ Create a Series with both index and values equal to the index keys useful with map for returning an indexer based on an index. Parameters ---------- keep_tz : optional, defaults True Return the data keeping the timezone. If keep_tz is True: If the timezone is not set, the resulting Series will have a datetime64[ns] dtype. Otherwise the Series will have an datetime64[ns, tz] dtype; the tz will be preserved. If keep_tz is False: Series will have a datetime64[ns] dtype. TZ aware objects will have the tz removed. .. versionchanged:: 1.0.0 The default value is now True. In a future version, this keyword will be removed entirely. Stop passing the argument to obtain the future behavior and silence the warning. index : Index, optional Index of resulting Series. If None, defaults to original index. name : str, optional Name of resulting Series. If None, defaults to name of original index. Returns ------- Series """ from pandas import Series if index is None: index = self._shallow_copy() if name is None: name = self.name if keep_tz is not lib.no_default: if keep_tz: warnings.warn( "The 'keep_tz' keyword in DatetimeIndex.to_series " "is deprecated and will be removed in a future version. " "You can stop passing 'keep_tz' to silence this warning.", FutureWarning, stacklevel=2, ) else: warnings.warn( "Specifying 'keep_tz=False' is deprecated and this " "option will be removed in a future release. If " "you want to remove the timezone information, you " "can do 'idx.tz_convert(None)' before calling " "'to_series'.", FutureWarning, stacklevel=2, ) else: keep_tz = True if keep_tz and self.tz is not None: # preserve the tz & copy values = self.copy(deep=True) else: values = self._values.view("M8[ns]").copy() return Series(values, index=index, name=name) def snap(self, freq="S"): """ Snap time stamps to nearest occurring frequency. Returns ------- DatetimeIndex """ # Superdumb, punting on any optimizing freq = to_offset(freq) snapped = np.empty(len(self), dtype=DT64NS_DTYPE) 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 snapped[i] = s dta = DatetimeArray(snapped, dtype=self.dtype) return DatetimeIndex._simple_new(dta, name=self.name) # -------------------------------------------------------------------- # Indexing Methods def _parsed_string_to_bounds(self, reso: Resolution, parsed: datetime): """ Calculate datetime bounds for parsed time string and its resolution. Parameters ---------- reso : str Resolution provided by parsed string. parsed : datetime Datetime from parsed string. Returns ------- lower, upper: pd.Timestamp """ assert isinstance(reso, Resolution), (type(reso), reso) valid_resos = { "year", "month", "quarter", "day", "hour", "minute", "second", "minute", "second", "microsecond", } if reso.attrname not in valid_resos: raise KeyError grp = reso.freq_group per = Period(parsed, freq=grp) 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 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" ) start = start.tz_localize(parsed.tzinfo).tz_convert(self.tz) end = end.tz_localize(parsed.tzinfo).tz_convert(self.tz) elif self.tz is not None: start = start.tz_localize(self.tz) end = end.tz_localize(self.tz) return start, end def _validate_partial_date_slice(self, reso: Resolution): assert isinstance(reso, Resolution), (type(reso), reso) if ( self.is_monotonic and reso.attrname in ["day", "hour", "minute", "second"] and self._resolution_obj >= reso ): # These resolution/monotonicity validations came from GH3931, # GH3452 and GH2369. # See also GH14826 raise KeyError if reso == "microsecond": # _partial_date_slice doesn't allow microsecond resolution, but # _parsed_string_to_bounds allows it. raise KeyError def _deprecate_mismatched_indexing(self, key): # GH#36148 # we get here with isinstance(key, self._data._recognized_scalars) try: self._data._assert_tzawareness_compat(key) except TypeError: if self.tz is None: msg = ( "Indexing a timezone-naive DatetimeIndex with a " "timezone-aware datetime is deprecated and will " "raise KeyError in a future version. " "Use a timezone-naive object instead." ) else: msg = ( "Indexing a timezone-aware DatetimeIndex with a " "timezone-naive datetime is deprecated and will " "raise KeyError in a future version. " "Use a timezone-aware object instead." ) warnings.warn(msg, FutureWarning, stacklevel=5) def get_loc(self, key, method=None, tolerance=None): """ Get integer location for requested label Returns ------- loc : int """ if not is_scalar(key): raise InvalidIndexError(key) orig_key = key if is_valid_nat_for_dtype(key, self.dtype): key = NaT if isinstance(key, self._data._recognized_scalars): # needed to localize naive datetimes self._deprecate_mismatched_indexing(key) key = self._maybe_cast_for_get_loc(key) elif isinstance(key, str): try: return self._get_string_slice(key) except (TypeError, KeyError, ValueError, OverflowError): pass try: key = self._maybe_cast_for_get_loc(key) except ValueError as err: raise KeyError(key) from err elif isinstance(key, timedelta): # GH#20464 raise TypeError( f"Cannot index {type(self).__name__} with {type(key).__name__}" ) elif isinstance(key, time): if method is not None: raise NotImplementedError( "cannot yet lookup inexact labels when key is a time object" ) return self.indexer_at_time(key) else: # unrecognized type raise KeyError(key) try: return Index.get_loc(self, key, method, tolerance) except KeyError as err: raise KeyError(orig_key) from err def _maybe_cast_for_get_loc(self, key) -> Timestamp: # needed to localize naive datetimes or dates (GH 35690) key = Timestamp(key) if key.tzinfo is None: key = key.tz_localize(self.tz) else: key = key.tz_convert(self.tz) return key def _maybe_cast_slice_bound(self, label, side: str, kind): """ If label is a string, cast it to datetime according to resolution. Parameters ---------- label : object side : {'left', 'right'} kind : {'loc', 'getitem'} or None Returns ------- label : object Notes ----- Value of `side` parameter should be validated in caller. """ assert kind in ["loc", "getitem", None] if isinstance(label, str): freq = getattr(self, "freqstr", getattr(self, "inferred_freq", None)) try: parsed, reso = parsing.parse_time_string(label, freq) except parsing.DateParseError as err: raise self._invalid_indexer("slice", label) from err reso = Resolution.from_attrname(reso) lower, upper = self._parsed_string_to_bounds(reso, parsed) # lower, upper form the half-open interval: # [parsed, parsed + 1 freq) # because label may be passed to searchsorted # the bounds need swapped if index is reverse sorted and has a # length > 1 (is_monotonic_decreasing gives True for empty # and length 1 index) if self._is_strictly_monotonic_decreasing and len(self) > 1: return upper if side == "left" else lower return lower if side == "left" else upper elif isinstance(label, (self._data._recognized_scalars, date)): self._deprecate_mismatched_indexing(label) else: raise self._invalid_indexer("slice", label) return self._maybe_cast_for_get_loc(label) def _get_string_slice(self, key: str): freq = getattr(self, "freqstr", getattr(self, "inferred_freq", None)) parsed, reso = parsing.parse_time_string(key, freq) reso = Resolution.from_attrname(reso) loc = self._partial_date_slice(reso, parsed) return loc def slice_indexer(self, start=None, end=None, step=None, kind=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, time) and isinstance(end, 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, time) or isinstance(end, time): raise KeyError("Cannot mix time and non-time slice keys") # Pandas supports slicing with dates, treated as datetimes at midnight. # https://github.com/pandas-dev/pandas/issues/31501 if isinstance(start, date) and not isinstance(start, datetime): start = datetime.combine(start, time(0, 0)) if isinstance(end, date) and not isinstance(end, datetime): end = datetime.combine(end, time(0, 0)) try: return Index.slice_indexer(self, start, end, step, kind=kind) except KeyError: # For historical reasons DatetimeIndex by default supports # value-based partial (aka string) slices on non-monotonic arrays, # let's try that. if (start is None or isinstance(start, str)) and ( end is None or isinstance(end, str) ): mask = np.array(True) deprecation_mask = np.array(True) if start is not None: start_casted = self._maybe_cast_slice_bound(start, "left", kind) mask = start_casted <= self deprecation_mask = start_casted == self if end is not None: end_casted = self._maybe_cast_slice_bound(end, "right", kind) mask = (self <= end_casted) & mask deprecation_mask = (end_casted == self) | deprecation_mask if not deprecation_mask.any(): warnings.warn( "Value based partial slicing on non-monotonic DatetimeIndexes " "with non-existing keys is deprecated and will raise a " "KeyError in a future Version.", FutureWarning, stacklevel=5, ) indexer = mask.nonzero()[0][::step] if len(indexer) == len(self): return slice(None) else: return indexer else: raise # -------------------------------------------------------------------- @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=False): """ Return index locations of values at particular time of day (e.g. 9:30AM). 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 ------- values_at_time : array of integers 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 (micros == time_micros).nonzero()[0] def indexer_between_time( self, start_time, end_time, include_start=True, include_end=True ): """ Return index locations of values between particular times of day (e.g., 9:00-9:30AM). 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 ------- values_between_time : array of integers 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=False, name=None, closed=None, **kwargs, ) -> DatetimeIndex: """ Return a fixed frequency DatetimeIndex. 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 or DateOffset, default 'D' Frequency strings can have multiples, e.g. '5H'. See :ref:`here ` 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. normalize : bool, default False Normalize start/end dates to midnight before generating date range. name : str, default None Name of the resulting DatetimeIndex. closed : {None, 'left', 'right'}, optional Make the interval closed with respect to the given frequency to the 'left', 'right', or both sides (None, the default). **kwargs For compatibility. Has no effect on the result. Returns ------- rng : 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 `__. 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 `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') `closed` controls whether to include `start` and `end` that are on the boundary. The default includes boundary points on either end. >>> pd.date_range(start='2017-01-01', end='2017-01-04', closed=None) DatetimeIndex(['2017-01-01', '2017-01-02', '2017-01-03', '2017-01-04'], dtype='datetime64[ns]', freq='D') Use ``closed='left'`` to exclude `end` if it falls on the boundary. >>> pd.date_range(start='2017-01-01', end='2017-01-04', closed='left') DatetimeIndex(['2017-01-01', '2017-01-02', '2017-01-03'], dtype='datetime64[ns]', freq='D') Use ``closed='right'`` to exclude `start` if it falls on the boundary. >>> pd.date_range(start='2017-01-01', end='2017-01-04', closed='right') DatetimeIndex(['2017-01-02', '2017-01-03', '2017-01-04'], dtype='datetime64[ns]', freq='D') """ 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, closed=closed, **kwargs, ) return DatetimeIndex._simple_new(dtarr, name=name) def bdate_range( start=None, end=None, periods=None, freq="B", tz=None, normalize=True, name=None, weekmask=None, holidays=None, closed=None, **kwargs, ) -> DatetimeIndex: """ Return a fixed frequency DatetimeIndex, with business day as the default frequency. 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 or DateOffset, default 'B' (business daily) Frequency strings can have multiples, e.g. '5H'. 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. closed : str, default None Make the interval closed with respect to the given frequency to the 'left', 'right', or both sides (None). **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 `__. 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, closed=closed, **kwargs, ) def _time_to_micros(time_obj: time) -> int: seconds = time_obj.hour * 60 * 60 + 60 * time_obj.minute + time_obj.second return 1_000_000 * seconds + time_obj.microsecond