Третий коммит, добавление share, share_kb, а также ADMIN_ID

myenv/Lib/site-packages/attr/converters.py

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+# SPDX-License-Identifier: MIT
+
+"""
+Commonly useful converters.
+"""
+
+import typing
+
+from ._compat import _AnnotationExtractor
+from ._make import NOTHING, Converter, Factory, pipe
+
+
+__all__ = [
+    "default_if_none",
+    "optional",
+    "pipe",
+    "to_bool",
+]
+
+
+def optional(converter):
+    """
+    A converter that allows an attribute to be optional. An optional attribute
+    is one which can be set to `None`.
+
+    Type annotations will be inferred from the wrapped converter's, if it has
+    any.
+
+    Args:
+        converter (typing.Callable):
+            the converter that is used for non-`None` values.
+
+    .. versionadded:: 17.1.0
+    """
+
+    if isinstance(converter, Converter):
+
+        def optional_converter(val, inst, field):
+            if val is None:
+                return None
+            return converter(val, inst, field)
+
+    else:
+
+        def optional_converter(val):
+            if val is None:
+                return None
+            return converter(val)
+
+    xtr = _AnnotationExtractor(converter)
+
+    t = xtr.get_first_param_type()
+    if t:
+        optional_converter.__annotations__["val"] = typing.Optional[t]
+
+    rt = xtr.get_return_type()
+    if rt:
+        optional_converter.__annotations__["return"] = typing.Optional[rt]
+
+    if isinstance(converter, Converter):
+        return Converter(optional_converter, takes_self=True, takes_field=True)
+
+    return optional_converter
+
+
+def default_if_none(default=NOTHING, factory=None):
+    """
+    A converter that allows to replace `None` values by *default* or the result
+    of *factory*.
+
+    Args:
+        default:
+            Value to be used if `None` is passed. Passing an instance of
+            `attrs.Factory` is supported, however the ``takes_self`` option is
+            *not*.
+
+        factory (typing.Callable):
+            A callable that takes no parameters whose result is used if `None`
+            is passed.
+
+    Raises:
+        TypeError: If **neither** *default* or *factory* is passed.
+
+        TypeError: If **both** *default* and *factory* are passed.
+
+        ValueError:
+            If an instance of `attrs.Factory` is passed with
+            ``takes_self=True``.
+
+    .. versionadded:: 18.2.0
+    """
+    if default is NOTHING and factory is None:
+        msg = "Must pass either `default` or `factory`."
+        raise TypeError(msg)
+
+    if default is not NOTHING and factory is not None:
+        msg = "Must pass either `default` or `factory` but not both."
+        raise TypeError(msg)
+
+    if factory is not None:
+        default = Factory(factory)
+
+    if isinstance(default, Factory):
+        if default.takes_self:
+            msg = "`takes_self` is not supported by default_if_none."
+            raise ValueError(msg)
+
+        def default_if_none_converter(val):
+            if val is not None:
+                return val
+
+            return default.factory()
+
+    else:
+
+        def default_if_none_converter(val):
+            if val is not None:
+                return val
+
+            return default
+
+    return default_if_none_converter
+
+
+def to_bool(val):
+    """
+    Convert "boolean" strings (for example, from environment variables) to real
+    booleans.
+
+    Values mapping to `True`:
+
+    - ``True``
+    - ``"true"`` / ``"t"``
+    - ``"yes"`` / ``"y"``
+    - ``"on"``
+    - ``"1"``
+    - ``1``
+
+    Values mapping to `False`:
+
+    - ``False``
+    - ``"false"`` / ``"f"``
+    - ``"no"`` / ``"n"``
+    - ``"off"``
+    - ``"0"``
+    - ``0``
+
+    Raises:
+        ValueError: For any other value.
+
+    .. versionadded:: 21.3.0
+    """
+    if isinstance(val, str):
+        val = val.lower()
+
+    if val in (True, "true", "t", "yes", "y", "on", "1", 1):
+        return True
+    if val in (False, "false", "f", "no", "n", "off", "0", 0):
+        return False
+
+    msg = f"Cannot convert value to bool: {val!r}"
+    raise ValueError(msg)