Source code for astropy.cosmology.connect
# Licensed under a 3-clause BSD style license - see LICENSE.rst
from __future__ import annotations
from typing import TYPE_CHECKING, TypeVar, overload
from astropy.cosmology import units as cu
from astropy.io import registry as io_registry
from astropy.units import add_enabled_units
if TYPE_CHECKING:
from collections.abc import Mapping
from typing import Any, Literal
from astropy.cosmology import Cosmology
from astropy.cosmology._io.model import _CosmologyModel
from astropy.table import Row, Table
__all__ = [
"CosmologyRead",
"CosmologyWrite",
"CosmologyFromFormat",
"CosmologyToFormat",
]
__doctest_skip__ = __all__
# NOTE: private b/c RTD error
_CosmoT = TypeVar("_CosmoT", bound="Cosmology")
_MT = TypeVar("_MT", bound="Mapping") # type: ignore[type-arg]
# ==============================================================================
# Read / Write
readwrite_registry = io_registry.UnifiedIORegistry()
[docs]
class CosmologyRead(io_registry.UnifiedReadWrite):
"""Read and parse data to a `~astropy.cosmology.Cosmology`.
This function provides the Cosmology interface to the Astropy unified I/O
layer. This allows easily reading a file in supported data formats using
syntax such as::
>>> from astropy.cosmology import Cosmology
>>> cosmo1 = Cosmology.read('<file name>')
When the ``read`` method is called from a subclass the subclass will
provide a keyword argument ``cosmology=<class>`` to the registered read
method. The method uses this cosmology class, regardless of the class
indicated in the file, and sets parameters' default values from the class'
signature.
Get help on the available readers using the ``help()`` method::
>>> Cosmology.read.help() # Get help reading and list supported formats
>>> Cosmology.read.help(format='<format>') # Get detailed help on a format
>>> Cosmology.read.list_formats() # Print list of available formats
See also: https://docs.astropy.org/en/stable/io/unified.html
Parameters
----------
*args
Positional arguments passed through to data reader. If supplied the
first argument is typically the input filename.
format : str (optional, keyword-only)
File format specifier.
**kwargs
Keyword arguments passed through to data reader.
Returns
-------
out : `~astropy.cosmology.Cosmology` subclass instance
`~astropy.cosmology.Cosmology` corresponding to file contents.
Notes
-----
"""
def __init__(self, instance: Cosmology, cosmo_cls: type[Cosmology]) -> None:
super().__init__(instance, cosmo_cls, "read", registry=readwrite_registry)
[docs]
def __call__(self, *args: Any, **kwargs: Any) -> Cosmology:
from astropy.cosmology.core import Cosmology
# so subclasses can override, also pass the class as a kwarg.
# allows for `FlatLambdaCDM.read` and
# `Cosmology.read(..., cosmology=FlatLambdaCDM)`
if self._cls is not Cosmology:
kwargs.setdefault("cosmology", self._cls) # set, if not present
# check that it is the correct cosmology, can be wrong if user
# passes in e.g. `w0wzCDM.read(..., cosmology=FlatLambdaCDM)`
valid = (self._cls, self._cls.__qualname__)
if kwargs["cosmology"] not in valid:
raise ValueError(
"keyword argument `cosmology` must be either the class "
f"{valid[0]} or its qualified name '{valid[1]}'"
)
with add_enabled_units(cu):
cosmo = self.registry.read(self._cls, *args, **kwargs)
return cosmo
[docs]
class CosmologyWrite(io_registry.UnifiedReadWrite):
"""Write this Cosmology object out in the specified format.
This function provides the Cosmology interface to the astropy unified I/O
layer. This allows easily writing a file in supported data formats
using syntax such as::
>>> from astropy.cosmology import Planck18
>>> Planck18.write('<file name>')
Get help on the available writers for ``Cosmology`` using the ``help()``
method::
>>> Cosmology.write.help() # Get help writing and list supported formats
>>> Cosmology.write.help(format='<format>') # Get detailed help on format
>>> Cosmology.write.list_formats() # Print list of available formats
Parameters
----------
*args
Positional arguments passed through to data writer. If supplied the
first argument is the output filename.
format : str (optional, keyword-only)
File format specifier.
**kwargs
Keyword arguments passed through to data writer.
Notes
-----
"""
def __init__(self, instance: Cosmology, cls: type[Cosmology]) -> None:
super().__init__(instance, cls, "write", registry=readwrite_registry)
[docs]
def __call__(self, *args: Any, **kwargs: Any) -> None:
self.registry.write(self._instance, *args, **kwargs)
# ==============================================================================
# Format Interchange
# for transforming instances, e.g. Cosmology <-> dict
convert_registry = io_registry.UnifiedIORegistry()
[docs]
class CosmologyFromFormat(io_registry.UnifiedReadWrite):
"""Transform object to a `~astropy.cosmology.Cosmology`.
This function provides the Cosmology interface to the Astropy unified I/O
layer. This allows easily parsing supported data formats using
syntax such as::
>>> from astropy.cosmology import Cosmology
>>> cosmo1 = Cosmology.from_format(cosmo_mapping, format='mapping')
When the ``from_format`` method is called from a subclass the subclass will
provide a keyword argument ``cosmology=<class>`` to the registered parser.
The method uses this cosmology class, regardless of the class indicated in
the data, and sets parameters' default values from the class' signature.
Get help on the available readers using the ``help()`` method::
>>> Cosmology.from_format.help() # Get help and list supported formats
>>> Cosmology.from_format.help('<format>') # Get detailed help on a format
>>> Cosmology.from_format.list_formats() # Print list of available formats
See also: https://docs.astropy.org/en/stable/io/unified.html
Parameters
----------
obj : object
The object to parse according to 'format'
*args
Positional arguments passed through to data parser.
format : str or None, optional keyword-only
Object format specifier. For `None` (default) CosmologyFromFormat tries
to identify the correct format.
**kwargs
Keyword arguments passed through to data parser.
Parsers should accept the following keyword arguments:
- cosmology : the class (or string name thereof) to use / check when
constructing the cosmology instance.
Returns
-------
out : `~astropy.cosmology.Cosmology` subclass instance
`~astropy.cosmology.Cosmology` corresponding to ``obj`` contents.
"""
def __init__(self, instance: Cosmology, cosmo_cls: type[Cosmology]) -> None:
super().__init__(instance, cosmo_cls, "read", registry=convert_registry)
# ===============================================================
# __call__ overloads
# note: format: ... | None means the format can be auto-detected from the input.
@overload
def __call__(
self,
obj: _CosmoT,
*args: Any,
format: Literal["astropy.cosmology"] | None,
**kwargs: Any,
) -> _CosmoT: ...
@overload
def __call__(
self,
obj: _CosmologyModel,
*args: Any,
format: Literal["astropy.model"] | None,
**kwargs: Any,
) -> Cosmology: ...
@overload
def __call__(
self, obj: Row, *args: Any, format: Literal["astropy.row"] | None, **kwargs: Any
) -> Cosmology: ...
@overload
def __call__(
self,
obj: Table,
*args: Any,
format: Literal["astropy.table"] | None,
**kwargs: Any,
) -> Cosmology: ...
@overload
def __call__(
self,
obj: Mapping[str, Any],
*args: Any,
format: Literal["mapping"] | None,
**kwargs: Any,
) -> Cosmology: ...
@overload
def __call__(
self, obj: str, *args: Any, format: Literal["yaml"], **kwargs: Any
) -> Cosmology: ...
@overload
def __call__(
self, obj: Any, *args: Any, format: str | None = None, **kwargs: Any
) -> Cosmology: ...
[docs]
def __call__(
self, obj: Any, *args: Any, format: str | None = None, **kwargs: Any
) -> Cosmology:
from astropy.cosmology.core import Cosmology
# so subclasses can override, also pass the class as a kwarg.
# allows for `FlatLambdaCDM.read` and
# `Cosmology.read(..., cosmology=FlatLambdaCDM)`
if self._cls is not Cosmology:
kwargs.setdefault("cosmology", self._cls) # set, if not present
# check that it is the correct cosmology, can be wrong if user
# passes in e.g. `w0wzCDM.read(..., cosmology=FlatLambdaCDM)`
valid = (self._cls, self._cls.__qualname__)
if kwargs["cosmology"] not in valid:
raise ValueError(
"keyword argument `cosmology` must be either the class "
f"{valid[0]} or its qualified name '{valid[1]}'"
)
with add_enabled_units(cu):
cosmo = self.registry.read(self._cls, obj, *args, format=format, **kwargs)
return cosmo
[docs]
class CosmologyToFormat(io_registry.UnifiedReadWrite):
"""Transform this Cosmology to another format.
This function provides the Cosmology interface to the astropy unified I/O
layer. This allows easily transforming to supported data formats
using syntax such as::
>>> from astropy.cosmology import Planck18
>>> Planck18.to_format("mapping")
{'cosmology': astropy.cosmology.core.FlatLambdaCDM,
'name': 'Planck18',
'H0': <Quantity 67.66 km / (Mpc s)>,
'Om0': 0.30966,
...
Get help on the available representations for ``Cosmology`` using the
``help()`` method::
>>> Cosmology.to_format.help() # Get help and list supported formats
>>> Cosmology.to_format.help('<format>') # Get detailed help on format
>>> Cosmology.to_format.list_formats() # Print list of available formats
Parameters
----------
format : str
Format specifier.
*args
Positional arguments passed through to data writer. If supplied the
first argument is the output filename.
**kwargs
Keyword arguments passed through to data writer.
"""
def __init__(self, instance: Cosmology, cls: type[Cosmology]) -> None:
super().__init__(instance, cls, "write", registry=convert_registry)
# ===============================================================
# __call__ overloads
@overload
def __call__(
self, format: Literal["astropy.cosmology"], *args: Any, **kwargs: Any
) -> Cosmology: ...
@overload
def __call__(
self, format: Literal["astropy.model"], *args: Any, **kwargs: Any
) -> _CosmologyModel: ...
@overload
def __call__(
self, format: Literal["astropy.row"], *args: Any, **kwargs: Any
) -> Row: ...
@overload
def __call__(
self, format: Literal["astropy.table"], *args: Any, **kwargs: Any
) -> Table: ...
@overload # specific mapping option, where the mapping class is specified.
def __call__(
self, format: Literal["mapping"], *args: Any, cls: _MT, **kwargs: Any
) -> _MT: ...
@overload
def __call__(
self, format: Literal["mapping"], *args: Any, **kwargs: Any
) -> dict[str, Any]: ...
@overload
def __call__(self, format: Literal["yaml"], *args: Any, **kwargs: Any) -> str: ...
@overload
def __call__(self, format: str, *args: Any, **kwargs: Any) -> Any: ...
[docs]
def __call__(self, format: str, *args: Any, **kwargs: Any) -> Any:
return self.registry.write(self._instance, None, *args, format=format, **kwargs)