| | """Helpful functions used internally within arrow.""" |
| |
|
| | import datetime |
| | from typing import Any, Optional, cast |
| |
|
| | from dateutil.rrule import WEEKLY, rrule |
| |
|
| | from arrow.constants import ( |
| | MAX_ORDINAL, |
| | MAX_TIMESTAMP, |
| | MAX_TIMESTAMP_MS, |
| | MAX_TIMESTAMP_US, |
| | MIN_ORDINAL, |
| | ) |
| |
|
| |
|
| | def next_weekday( |
| | start_date: Optional[datetime.date], weekday: int |
| | ) -> datetime.datetime: |
| | """Get next weekday from the specified start date. |
| | |
| | :param start_date: Datetime object representing the start date. |
| | :param weekday: Next weekday to obtain. Can be a value between 0 (Monday) and 6 (Sunday). |
| | :return: Datetime object corresponding to the next weekday after start_date. |
| | |
| | Usage:: |
| | |
| | # Get first Monday after epoch |
| | >>> next_weekday(datetime(1970, 1, 1), 0) |
| | 1970-01-05 00:00:00 |
| | |
| | # Get first Thursday after epoch |
| | >>> next_weekday(datetime(1970, 1, 1), 3) |
| | 1970-01-01 00:00:00 |
| | |
| | # Get first Sunday after epoch |
| | >>> next_weekday(datetime(1970, 1, 1), 6) |
| | 1970-01-04 00:00:00 |
| | """ |
| | if weekday < 0 or weekday > 6: |
| | raise ValueError("Weekday must be between 0 (Monday) and 6 (Sunday).") |
| | return cast( |
| | datetime.datetime, |
| | rrule(freq=WEEKLY, dtstart=start_date, byweekday=weekday, count=1)[0], |
| | ) |
| |
|
| |
|
| | def is_timestamp(value: Any) -> bool: |
| | """Check if value is a valid timestamp.""" |
| | if isinstance(value, bool): |
| | return False |
| | if not isinstance(value, (int, float, str)): |
| | return False |
| | try: |
| | float(value) |
| | return True |
| | except ValueError: |
| | return False |
| |
|
| |
|
| | def validate_ordinal(value: Any) -> None: |
| | """Raise an exception if value is an invalid Gregorian ordinal. |
| | |
| | :param value: the input to be checked |
| | |
| | """ |
| | if isinstance(value, bool) or not isinstance(value, int): |
| | raise TypeError(f"Ordinal must be an integer (got type {type(value)}).") |
| | if not (MIN_ORDINAL <= value <= MAX_ORDINAL): |
| | raise ValueError(f"Ordinal {value} is out of range.") |
| |
|
| |
|
| | def normalize_timestamp(timestamp: float) -> float: |
| | """Normalize millisecond and microsecond timestamps into normal timestamps.""" |
| | if timestamp > MAX_TIMESTAMP: |
| | if timestamp < MAX_TIMESTAMP_MS: |
| | timestamp /= 1000 |
| | elif timestamp < MAX_TIMESTAMP_US: |
| | timestamp /= 1_000_000 |
| | else: |
| | raise ValueError(f"The specified timestamp {timestamp!r} is too large.") |
| | return timestamp |
| |
|
| |
|
| | |
| | def iso_to_gregorian(iso_year: int, iso_week: int, iso_day: int) -> datetime.date: |
| | """Converts an ISO week date into a datetime object. |
| | |
| | :param iso_year: the year |
| | :param iso_week: the week number, each year has either 52 or 53 weeks |
| | :param iso_day: the day numbered 1 through 7, beginning with Monday |
| | |
| | """ |
| |
|
| | if not 1 <= iso_week <= 53: |
| | raise ValueError("ISO Calendar week value must be between 1-53.") |
| |
|
| | if not 1 <= iso_day <= 7: |
| | raise ValueError("ISO Calendar day value must be between 1-7") |
| |
|
| | |
| | fourth_jan = datetime.date(iso_year, 1, 4) |
| | delta = datetime.timedelta(fourth_jan.isoweekday() - 1) |
| | year_start = fourth_jan - delta |
| | gregorian = year_start + datetime.timedelta(days=iso_day - 1, weeks=iso_week - 1) |
| |
|
| | return gregorian |
| |
|
| |
|
| | def validate_bounds(bounds: str) -> None: |
| | if bounds != "()" and bounds != "(]" and bounds != "[)" and bounds != "[]": |
| | raise ValueError( |
| | "Invalid bounds. Please select between '()', '(]', '[)', or '[]'." |
| | ) |
| |
|
| |
|
| | __all__ = ["next_weekday", "is_timestamp", "validate_ordinal", "iso_to_gregorian"] |
| |
|
