mirror of
https://github.com/SickGear/SickGear.git
synced 2024-11-27 15:13:38 +00:00
141 lines
3.3 KiB
Python
141 lines
3.3 KiB
Python
# SPDX-License-Identifier: MIT
|
|
|
|
"""
|
|
Commonly useful converters.
|
|
"""
|
|
|
|
|
|
import typing
|
|
|
|
from ._compat import _AnnotationExtractor
|
|
from ._make import NOTHING, 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.
|
|
|
|
:param typing.Callable converter: the converter that is used for non-`None`
|
|
values.
|
|
|
|
.. versionadded:: 17.1.0
|
|
"""
|
|
|
|
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]
|
|
|
|
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*.
|
|
|
|
:param default: Value to be used if `None` is passed. Passing an instance
|
|
of `attrs.Factory` is supported, however the ``takes_self`` option is
|
|
*not*.
|
|
:param typing.Callable factory: A callable that takes no parameters whose
|
|
result is used if `None` is passed.
|
|
|
|
:raises TypeError: If **neither** *default* or *factory* is passed.
|
|
:raises TypeError: If **both** *default* and *factory* are passed.
|
|
:raises 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)
|