コード例 #1
0
ファイル: period.py プロジェクト: zhaofeng-hall/pandas
    def asfreq(self, freq=None, how: str = "E") -> "PeriodArray":
        """
        Convert the Period Array/Index to the specified frequency `freq`.

        Parameters
        ----------
        freq : str
            A frequency.
        how : str {'E', 'S'}
            Whether the elements should be aligned to the end
            or start within pa period.

            * 'E', 'END', or 'FINISH' for end,
            * 'S', 'START', or 'BEGIN' for start.

            January 31st ('END') vs. January 1st ('START') for example.

        Returns
        -------
        Period Array/Index
            Constructed with the new frequency.

        Examples
        --------
        >>> pidx = pd.period_range('2010-01-01', '2015-01-01', freq='A')
        >>> pidx
        PeriodIndex(['2010', '2011', '2012', '2013', '2014', '2015'],
        dtype='period[A-DEC]', freq='A-DEC')

        >>> pidx.asfreq('M')
        PeriodIndex(['2010-12', '2011-12', '2012-12', '2013-12', '2014-12',
        '2015-12'], dtype='period[M]', freq='M')

        >>> pidx.asfreq('M', how='S')
        PeriodIndex(['2010-01', '2011-01', '2012-01', '2013-01', '2014-01',
        '2015-01'], dtype='period[M]', freq='M')
        """
        how = libperiod.validate_end_alias(how)

        freq = Period._maybe_convert_freq(freq)

        base1 = self.freq._period_dtype_code
        base2 = freq._period_dtype_code

        asi8 = self.asi8
        # self.freq.n can't be negative or 0
        end = how == "E"
        if end:
            ordinal = asi8 + self.freq.n - 1
        else:
            ordinal = asi8

        new_data = period_asfreq_arr(ordinal, base1, base2, end)

        if self._hasnans:
            new_data[self._isnan] = iNaT

        return type(self)(new_data, freq=freq)
コード例 #2
0
    def to_timestamp(self, freq=None, how: str = "start") -> DatetimeArray:
        """
        Cast to DatetimeArray/Index.

        Parameters
        ----------
        freq : str or DateOffset, optional
            Target frequency. The default is 'D' for week or longer,
            'S' otherwise.
        how : {'s', 'e', 'start', 'end'}
            Whether to use the start or end of the time period being converted.

        Returns
        -------
        DatetimeArray/Index
        """
        from pandas.core.arrays import DatetimeArray

        how = libperiod.validate_end_alias(how)

        end = how == "E"
        if end:
            if freq == "B" or self.freq == "B":
                # roll forward to ensure we land on B date
                adjust = Timedelta(1, "D") - Timedelta(1, "ns")
                return self.to_timestamp(how="start") + adjust
            else:
                adjust = Timedelta(1, "ns")
                return (self + self.freq).to_timestamp(how="start") - adjust

        if freq is None:
            freq = self._dtype._get_to_timestamp_base()
            base = freq
        else:
            freq = Period._maybe_convert_freq(freq)
            base = freq._period_dtype_code

        new_parr = self.asfreq(freq, how=how)

        new_data = libperiod.periodarr_to_dt64arr(new_parr.asi8, base)
        dta = DatetimeArray(new_data)

        if self.freq.name == "B":
            # See if we can retain BDay instead of Day in cases where
            #  len(self) is too small for infer_freq to distinguish between them
            diffs = libalgos.unique_deltas(self.asi8)
            if len(diffs) == 1:
                diff = diffs[0]
                if diff == self.freq.n:
                    dta._freq = self.freq
                elif diff == 1:
                    dta._freq = self.freq.base
                # TODO: other cases?
            return dta
        else:
            return dta._with_freq("infer")
コード例 #3
0
ファイル: period.py プロジェクト: yiligeng/pandas
    def to_timestamp(self, freq=None, how="start"):
        """
        Cast to DatetimeArray/Index.

        Parameters
        ----------
        freq : str or DateOffset, optional
            Target frequency. The default is 'D' for week or longer,
            'S' otherwise.
        how : {'s', 'e', 'start', 'end'}
            Whether to use the start or end of the time period being converted.

        Returns
        -------
        DatetimeArray/Index
        """
        from pandas.core.arrays import DatetimeArray

        how = libperiod.validate_end_alias(how)

        end = how == "E"
        if end:
            if freq == "B" or self.freq == "B":
                # roll forward to ensure we land on B date
                adjust = Timedelta(1, "D") - Timedelta(1, "ns")
                return self.to_timestamp(how="start") + adjust
            else:
                adjust = Timedelta(1, "ns")
                return (self + self.freq).to_timestamp(how="start") - adjust

        if freq is None:
            base = self.freq._period_dtype_code
            freq = libfrequencies.get_to_timestamp_base(base)
            base = freq
        else:
            freq = Period._maybe_convert_freq(freq)
            base = freq._period_dtype_code

        new_data = self.asfreq(freq, how=how)

        new_data = libperiod.periodarr_to_dt64arr(new_data.asi8, base)
        return DatetimeArray(new_data)._with_freq("infer")
コード例 #4
0
ファイル: period.py プロジェクト: Aathi410/Pro123
    def asfreq(self, freq=None, how: str = "E") -> PeriodArray:
        """
        Convert the {klass} to the specified frequency `freq`.

        Equivalent to applying :meth:`pandas.Period.asfreq` with the given arguments
        to each :class:`~pandas.Period` in this {klass}.

        Parameters
        ----------
        freq : str
            A frequency.
        how : str {{'E', 'S'}}, default 'E'
            Whether the elements should be aligned to the end
            or start within pa period.

            * 'E', 'END', or 'FINISH' for end,
            * 'S', 'START', or 'BEGIN' for start.

            January 31st ('END') vs. January 1st ('START') for example.

        Returns
        -------
        {klass}
            The transformed {klass} with the new frequency.

        See Also
        --------
        {other}.asfreq: Convert each Period in a {other_name} to the given frequency.
        Period.asfreq : Convert a :class:`~pandas.Period` object to the given frequency.

        Examples
        --------
        >>> pidx = pd.period_range('2010-01-01', '2015-01-01', freq='A')
        >>> pidx
        PeriodIndex(['2010', '2011', '2012', '2013', '2014', '2015'],
        dtype='period[A-DEC]')

        >>> pidx.asfreq('M')
        PeriodIndex(['2010-12', '2011-12', '2012-12', '2013-12', '2014-12',
        '2015-12'], dtype='period[M]')

        >>> pidx.asfreq('M', how='S')
        PeriodIndex(['2010-01', '2011-01', '2012-01', '2013-01', '2014-01',
        '2015-01'], dtype='period[M]')
        """
        how = libperiod.validate_end_alias(how)

        freq = Period._maybe_convert_freq(freq)

        base1 = self.freq._period_dtype_code
        base2 = freq._period_dtype_code

        asi8 = self.asi8
        # self.freq.n can't be negative or 0
        end = how == "E"
        if end:
            ordinal = asi8 + self.freq.n - 1
        else:
            ordinal = asi8

        new_data = period_asfreq_arr(ordinal, base1, base2, end)

        if self._hasnans:
            new_data[self._isnan] = iNaT

        return type(self)(new_data, freq=freq)