| """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"] |
|
|
