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BaseIsoWeek class

iso_week_date.base.BaseIsoWeek

Bases: ABC, ComparatorMixin, ConverterMixin, ParserMixin

Base abstract class for IsoWeek and IsoWeekDate classes.

It defines the common interface for both classes and implements the common methods between them.

Attributes:

Name Type Description
value_ str

stores the string value representing the iso-week date in the _format format.
offset_ timedelta

class variable, stores the offset to be used when converting to and from datetime and date objects.
_pattern Pattern

class variable, stores the regex pattern to validate iso-week string format. Semiprivate, do not use it directly.
_format str

class variable, stores the string format of the iso-week date. Semiprivate, do not use it directly.
_date_format str

class variable, stores the string format with datetime conventions. Semiprivate, do not use it directly.
Source code in iso_week_date/base.py 
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class BaseIsoWeek(ABC, ComparatorMixin, ConverterMixin, ParserMixin):
    """Base abstract class for `IsoWeek` and `IsoWeekDate` classes.

    It defines the common interface for both classes and implements the common methods between them.

    Attributes:
        value_: stores the string value representing the iso-week date in the `_format` format.
        offset_: class variable, stores the offset to be used when converting to and from `datetime` and `date` objects.
        _pattern: class variable, stores the regex pattern to validate iso-week string format. Semiprivate, do not use
            it directly.
        _format: class variable, stores the string format of the iso-week date. Semiprivate, do not use it directly.
        _date_format: class variable, stores the string format with datetime conventions. Semiprivate, do not use it
            directly.
    """

    offset_: ClassVar[timedelta] = timedelta(days=0)

    _pattern: ClassVar[re.Pattern]
    _format: ClassVar[str]
    _date_format: ClassVar[str]

    __slots__ = ("value_",)

    def __init__(self: Self, value: str) -> None:
        """Initializes `BaseIsoWeek` object from iso-week string.

        Arguments:
            value: ISO Week string to initialize `BaseIsoWeek` object, must match the `_pattern` pattern of the class,
                otherwise a `ValueError` will be raised.

        Raises:
            ValueError: If `value` does not match the `_pattern` pattern of the class.
        """
        self.value_: str = self._validate(value)

    @classmethod
    def _validate(cls: Type[Self], value: str) -> str:
        """Validates iso-week string format against `_pattern`."""
        _match = re.match(cls._pattern, value)

        if not _match:
            raise ValueError(format_err_msg(cls._format, value))

        year, week = int(_match.group(1)), int(_match.group(2)[1:])

        if weeks_of_year(year) < week:
            msg = f"Invalid week number. Year {year} has only {weeks_of_year(year)} weeks."
            raise ValueError(msg)

        return value

    def __repr__(self: Self) -> str:
        """Custom representation."""
        return f"{self.name}({self.value_}) with offset {self.offset_}"

    def __str__(self: Self) -> str:
        """String conversion operator, returns iso-week string value ignoring offset."""
        return self.value_

    @classproperty
    def _compact_pattern(cls: Type[IsoWeekProtocol]) -> re.Pattern:  # noqa: N805
        """Returns compiled compact pattern."""
        return re.compile(cls._pattern.pattern.replace(")-(", ")("))

    @classproperty
    def _compact_format(cls: Type[IsoWeekProtocol]) -> str:  # noqa: N805
        """Returns compact format as string."""
        return cls._format.replace("-", "")

    @property
    def name(self: Self) -> str:
        """Returns class name."""
        return self.__class__.__name__

    @property
    def year(self: Self) -> int:
        """Returns year number as integer.

        Examples:
        ```py
        from iso_week_date import IsoWeek, IsoWeekDate

        IsoWeek("2023-W01").year  # 2023
        IsoWeekDate("2023-W01-1").year  # 2023
        ```
        """
        return int(self.value_[:4])

    @property
    def week(self: Self) -> int:
        """Returns week number as integer.

        Examples:
        ```py
        from iso_week_date import IsoWeek, IsoWeekDate

        IsoWeek("2023-W01").week  # 1
        IsoWeekDate("2023-W01-1").week  # 1
        ```
        """
        return int(self.value_[6:8])

    @property
    def quarter(self: Self) -> int:
        """Returns quarter number as integer.

        The first three quarters have 13 weeks, while the last one has either 13 or 14 weeks depending on the year:

        - Q1: weeks from 1 to 13
        - Q2: weeks from 14 to 26
        - Q3: weeks from 27 to 39
        - Q4: weeks from 40 to 52 (or 53 if applicable)

        Examples:
        ```py
        from iso_week_date import IsoWeek, IsoWeekDate

        IsoWeek("2023-W01").quarter  # 1
        IsoWeekDate("2023-W52-1").quarter  # 4
        ```
        """
        return min((self.week - 1) // 13 + 1, 4)

    @overload
    def __add__(self: Self, other: Union[int, timedelta]) -> Self: ...  # pragma: no cover

    @overload
    def __add__(
        self: Self,
        other: Iterable[Union[int, timedelta]],
    ) -> Generator[Self, None, None]: ...  # pragma: no cover

    @overload
    def __add__(
        self: Self,
        other: Union[int, timedelta, Iterable[Union[int, timedelta]]],
    ) -> Union[Self, Generator[Self, None, None]]: ...  # pragma: no cover

    @abstractmethod
    def __add__(
        self: Self,
        other: Union[int, timedelta, Iterable[Union[int, timedelta]]],
    ) -> Union[Self, Generator[Self, None, None]]:  # pragma: no cover
        """Implementation of addition operator."""
        ...

    @overload
    def __sub__(self: Self, other: Union[int, timedelta]) -> Self: ...  # pragma: no cover

    @overload
    def __sub__(self: Self, other: Self) -> int: ...  # pragma: no cover

    @overload
    def __sub__(
        self: Self,
        other: Iterable[Union[int, timedelta]],
    ) -> Generator[Self, None, None]: ...  # pragma: no cover

    @overload
    def __sub__(self: Self, other: Iterable[Self]) -> Generator[int, None, None]: ...  # pragma: no cover

    @overload
    def __sub__(
        self: Self,
        other: Union[int, timedelta, Self, Iterable[Union[int, timedelta, Self]]],
    ) -> Union[int, Self, Generator[Union[int, Self], None, None]]: ...  # pragma: no cover

    @abstractmethod
    def __sub__(
        self: Self,
        other: Union[int, timedelta, Self, Iterable[Union[int, timedelta, Self]]],
    ) -> Union[int, Self, Generator[Union[int, Self], None, None]]:  # pragma: no cover
        """Implementation of subtraction operator."""
        ...

    def __next__(self: Self) -> Self:
        """Implementation of next operator."""
        return self + 1

    @overload
    @classmethod
    def range(
        cls: Type[Self],
        start: BaseIsoWeek_T,
        end: BaseIsoWeek_T,
        *,
        step: int = 1,
        inclusive: Literal["both", "left", "right", "neither"] = "both",
        as_str: Literal[True],
    ) -> Generator[str, None, None]: ...  # pragma: no cover

    @overload
    @classmethod
    def range(
        cls: Type[Self],
        start: BaseIsoWeek_T,
        end: BaseIsoWeek_T,
        *,
        step: int = 1,
        inclusive: Literal["both", "left", "right", "neither"] = "both",
        as_str: Literal[False],
    ) -> Generator[Self, None, None]: ...  # pragma: no cover

    @overload
    @classmethod
    def range(
        cls: Type[Self],
        start: BaseIsoWeek_T,
        end: BaseIsoWeek_T,
        *,
        step: int = 1,
        inclusive: Literal["both", "left", "right", "neither"] = "both",
        as_str: bool = True,
    ) -> Generator[Union[str, Self], None, None]: ...  # pragma: no cover

    @classmethod
    def range(
        cls: Type[Self],
        start: BaseIsoWeek_T,
        end: BaseIsoWeek_T,
        *,
        step: int = 1,
        inclusive: Literal["both", "left", "right", "neither"] = "both",
        as_str: bool = True,
    ) -> Generator[Union[str, Self], None, None]:
        """Generates `BaseIsoWeek` (or `str`) between `start` and `end` values with given `step`.

        `inclusive` parameter can be used to control inclusion of `start` and/or `end` week values.

        If `as_str` is flagged as `True`, it will return str values, otherwise it will return `BaseIsoWeek` objects.

        Arguments:
            start: Starting value. It can be `BaseIsoWeek`, `date`, `datetime` or `str`.
            end: Ending value. It can be `BaseIsoWeek`, `date`, `datetime` or `str`.
            step: Step between generated values, must be positive integer.
            inclusive: Inclusive type, can be one of "both", "left", "right" or "neither".
            as_str: Whether to return `str` or `BaseIsoWeek` object.

        Returns:
            Generator of `IsoWeeks`/`str` between `start` and `end` values with given `step`.

        Raises:
            ValueError: If any of the following conditions is met:

                - `start > end`.
                - `inclusive` not one of "both", "left", "right" or "neither".
                - `step` is not strictly positive.
            TypeError: If `step` is not an int.

        Examples:
        ```python
        from iso_week_date import IsoWeek

        tuple(
            IsoWeek.range(
                start="2023-W01",
                end="2023-W07",
                step=2,
                inclusive="both",
                as_str=True,
            )
        )
        # ('2023-W01', '2023-W03', '2023-W05', '2023-W07')
        ```
        """
        _start = cls._cast(start)
        _end = cls._cast(end)

        if _start > _end:
            msg = f"`start` must be before `end` value, found: {_start} > {_end}"
            raise ValueError(msg)

        if not isinstance(step, int):
            msg = f"`step` must be integer, found {type(step)}"
            raise TypeError(msg)

        if step < 1:
            msg = f"`step` value must be greater than or equal to 1, found {step}"
            raise ValueError(msg)

        if inclusive not in _inclusive_values:
            msg = f"Invalid `inclusive` value. Must be one of {_inclusive_values}"
            raise ValueError(msg)

        _delta = _end - _start
        range_start = 0 if inclusive in ("both", "left") else 1
        range_end = _delta + 1 if inclusive in ("both", "right") else _delta

        weeks_range: Generator[Union[str, Self], None, None] = (
            (_start + i).to_string() if as_str else _start + i for i in range(range_start, range_end, step)
        )

        return weeks_range

name: str property

Returns class name.

quarter: int property

Returns quarter number as integer.

The first three quarters have 13 weeks, while the last one has either 13 or 14 weeks depending on the year:

  • Q1: weeks from 1 to 13
  • Q2: weeks from 14 to 26
  • Q3: weeks from 27 to 39
  • Q4: weeks from 40 to 52 (or 53 if applicable)

Examples: 

from iso_week_date import IsoWeek, IsoWeekDate

IsoWeek("2023-W01").quarter  # 1
IsoWeekDate("2023-W52-1").quarter  # 4

week: int property

Returns week number as integer.

Examples: 

from iso_week_date import IsoWeek, IsoWeekDate

IsoWeek("2023-W01").week  # 1
IsoWeekDate("2023-W01-1").week  # 1

year: int property

Returns year number as integer.

Examples: 

from iso_week_date import IsoWeek, IsoWeekDate

IsoWeek("2023-W01").year  # 2023
IsoWeekDate("2023-W01-1").year  # 2023

__add__(other) abstractmethod

Implementation of addition operator.

Source code in iso_week_date/base.py 
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@abstractmethod
def __add__(
    self: Self,
    other: Union[int, timedelta, Iterable[Union[int, timedelta]]],
) -> Union[Self, Generator[Self, None, None]]:  # pragma: no cover
    """Implementation of addition operator."""
    ...

__init__(value)

Initializes BaseIsoWeek object from iso-week string.

Parameters:

Name Type Description Default
value str

ISO Week string to initialize BaseIsoWeek object, must match the _pattern pattern of the class, otherwise a ValueError will be raised.

 required

Raises:

Type Description
ValueError

If value does not match the _pattern pattern of the class.
Source code in iso_week_date/base.py 
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def __init__(self: Self, value: str) -> None:
    """Initializes `BaseIsoWeek` object from iso-week string.

    Arguments:
        value: ISO Week string to initialize `BaseIsoWeek` object, must match the `_pattern` pattern of the class,
            otherwise a `ValueError` will be raised.

    Raises:
        ValueError: If `value` does not match the `_pattern` pattern of the class.
    """
    self.value_: str = self._validate(value)

__next__()

Implementation of next operator.

Source code in iso_week_date/base.py 
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def __next__(self: Self) -> Self:
    """Implementation of next operator."""
    return self + 1

__repr__()

Custom representation.

Source code in iso_week_date/base.py 
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def __repr__(self: Self) -> str:
    """Custom representation."""
    return f"{self.name}({self.value_}) with offset {self.offset_}"

__str__()

String conversion operator, returns iso-week string value ignoring offset.

Source code in iso_week_date/base.py 
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def __str__(self: Self) -> str:
    """String conversion operator, returns iso-week string value ignoring offset."""
    return self.value_

__sub__(other) abstractmethod

Implementation of subtraction operator.

Source code in iso_week_date/base.py 
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@abstractmethod
def __sub__(
    self: Self,
    other: Union[int, timedelta, Self, Iterable[Union[int, timedelta, Self]]],
) -> Union[int, Self, Generator[Union[int, Self], None, None]]:  # pragma: no cover
    """Implementation of subtraction operator."""
    ...

range(start, end, *, step=1, inclusive='both', as_str=True) classmethod

Generates BaseIsoWeek (or str) between start and end values with given step.

inclusive parameter can be used to control inclusion of start and/or end week values.

If as_str is flagged as True, it will return str values, otherwise it will return BaseIsoWeek objects.

Parameters:

Name Type Description Default
start BaseIsoWeek_T

Starting value. It can be BaseIsoWeek, date, datetime or str.

 required
end BaseIsoWeek_T

Ending value. It can be BaseIsoWeek, date, datetime or str.

 required
step int

Step between generated values, must be positive integer.

 1
inclusive Literal['both', 'left', 'right', 'neither']

Inclusive type, can be one of "both", "left", "right" or "neither".

 'both'
as_str bool

Whether to return str or BaseIsoWeek object.

 True

Returns:

Type Description
None

Generator of IsoWeeks/str between start and end values with given step.

Raises:

Type Description
ValueError

If any of the following conditions is met:

  • start > end.
  • inclusive not one of "both", "left", "right" or "neither".
  • step is not strictly positive.
TypeError

If step is not an int.

Examples: 

from iso_week_date import IsoWeek

tuple(
    IsoWeek.range(
        start="2023-W01",
        end="2023-W07",
        step=2,
        inclusive="both",
        as_str=True,
    )
)
# ('2023-W01', '2023-W03', '2023-W05', '2023-W07')

Source code in iso_week_date/base.py 
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@classmethod
def range(
    cls: Type[Self],
    start: BaseIsoWeek_T,
    end: BaseIsoWeek_T,
    *,
    step: int = 1,
    inclusive: Literal["both", "left", "right", "neither"] = "both",
    as_str: bool = True,
) -> Generator[Union[str, Self], None, None]:
    """Generates `BaseIsoWeek` (or `str`) between `start` and `end` values with given `step`.

    `inclusive` parameter can be used to control inclusion of `start` and/or `end` week values.

    If `as_str` is flagged as `True`, it will return str values, otherwise it will return `BaseIsoWeek` objects.

    Arguments:
        start: Starting value. It can be `BaseIsoWeek`, `date`, `datetime` or `str`.
        end: Ending value. It can be `BaseIsoWeek`, `date`, `datetime` or `str`.
        step: Step between generated values, must be positive integer.
        inclusive: Inclusive type, can be one of "both", "left", "right" or "neither".
        as_str: Whether to return `str` or `BaseIsoWeek` object.

    Returns:
        Generator of `IsoWeeks`/`str` between `start` and `end` values with given `step`.

    Raises:
        ValueError: If any of the following conditions is met:

            - `start > end`.
            - `inclusive` not one of "both", "left", "right" or "neither".
            - `step` is not strictly positive.
        TypeError: If `step` is not an int.

    Examples:
    ```python
    from iso_week_date import IsoWeek

    tuple(
        IsoWeek.range(
            start="2023-W01",
            end="2023-W07",
            step=2,
            inclusive="both",
            as_str=True,
        )
    )
    # ('2023-W01', '2023-W03', '2023-W05', '2023-W07')
    ```
    """
    _start = cls._cast(start)
    _end = cls._cast(end)

    if _start > _end:
        msg = f"`start` must be before `end` value, found: {_start} > {_end}"
        raise ValueError(msg)

    if not isinstance(step, int):
        msg = f"`step` must be integer, found {type(step)}"
        raise TypeError(msg)

    if step < 1:
        msg = f"`step` value must be greater than or equal to 1, found {step}"
        raise ValueError(msg)

    if inclusive not in _inclusive_values:
        msg = f"Invalid `inclusive` value. Must be one of {_inclusive_values}"
        raise ValueError(msg)

    _delta = _end - _start
    range_start = 0 if inclusive in ("both", "left") else 1
    range_end = _delta + 1 if inclusive in ("both", "right") else _delta

    weeks_range: Generator[Union[str, Self], None, None] = (
        (_start + i).to_string() if as_str else _start + i for i in range(range_start, range_end, step)
    )

    return weeks_range