Skip to content

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 
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
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 
171
172
173
174
175
176
177
@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 
56
57
58
59
60
61
62
63
64
65
66
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 
208
209
210
def __next__(self: Self) -> Self:
    """Implementation of next operator."""
    return self + 1

__repr__()

Custom representation.

Source code in iso_week_date/base.py 
84
85
86
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 
88
89
90
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 
200
201
202
203
204
205
206
@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
Generator[Union[str, Self], None, 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 
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
@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