# Licensed under a 3-clause BSD style license - see LICENSE.rst
"""This module contains classes and functions to standardize access to
configuration files for Astropy and affiliated packages.
.. note::
The configuration system makes use of the 'configobj' package, which stores
configuration in a text format like that used in the standard library
`ConfigParser`. More information and documentation for configobj can be
found at https://configobj.readthedocs.io .
"""
import contextlib
import importlib
import io
import os
import pkgutil
import warnings
from contextlib import contextmanager, nullcontext
from pathlib import Path
from textwrap import TextWrapper
from warnings import warn
import configobj, validate
from astropy.utils import find_current_module, silence
from astropy.utils.exceptions import AstropyDeprecationWarning, AstropyWarning
from .paths import get_config_dir_path
__all__ = (
"InvalidConfigurationItemWarning",
"get_config",
"reload_config",
"ConfigNamespace",
"ConfigItem",
"generate_config",
"create_config_file",
)
[docs]
class InvalidConfigurationItemWarning(AstropyWarning):
"""A Warning that is issued when the configuration value specified in the
astropy configuration file does not match the type expected for that
configuration value.
"""
# these are not in __all__ because it's not intended that a user ever see them
class ConfigurationDefaultMissingError(ValueError):
"""An exception that is raised when the configuration defaults (which
should be generated at build-time) are missing.
"""
# this is used in astropy/__init__.py
class ConfigurationDefaultMissingWarning(AstropyWarning):
"""A warning that is issued when the configuration defaults (which
should be generated at build-time) are missing.
"""
class ConfigurationChangedWarning(AstropyWarning):
"""
A warning that the configuration options have changed.
"""
class _ConfigNamespaceMeta(type):
def __init__(cls, name, bases, dict):
if cls.__bases__[0] is object:
return
for key, val in dict.items():
if isinstance(val, ConfigItem):
val.name = key
[docs]
class ConfigNamespace(metaclass=_ConfigNamespaceMeta):
"""
A namespace of configuration items. Each subpackage with
configuration items should define a subclass of this class,
containing `ConfigItem` instances as members.
For example::
class Conf(_config.ConfigNamespace):
unicode_output = _config.ConfigItem(
False,
'Use Unicode characters when outputting values, ...')
use_color = _config.ConfigItem(
sys.platform != 'win32',
'When True, use ANSI color escape sequences when ...',
aliases=['astropy.utils.console.USE_COLOR'])
conf = Conf()
"""
def __iter__(self):
for key, val in self.__class__.__dict__.items():
if isinstance(val, ConfigItem):
yield key
def __str__(self):
try:
header = f"{self.__doc__.strip()}\n\n"
except AttributeError:
current_module = str(find_current_module(2)).split("'")[1]
header = f"Configuration parameters for `{current_module}`\n\n"
return header + "\n\n".join(map(str, self.values()))
keys = __iter__
"""Iterate over configuration item names."""
[docs]
def values(self):
"""Iterate over configuration item values."""
for val in self.__class__.__dict__.values():
if isinstance(val, ConfigItem):
yield val
[docs]
def items(self):
"""Iterate over configuration item ``(name, value)`` pairs."""
for key, val in self.__class__.__dict__.items():
if isinstance(val, ConfigItem):
yield key, val
[docs]
def help(self, name=None):
"""Print info about configuration items.
Parameters
----------
name : `str`, optional
Name of the configuration item to be described. If no name is
provided then info about all the configuration items will be
printed.
Examples
--------
>>> from astropy import conf
>>> conf.help("unicode_output")
ConfigItem: unicode_output
cfgtype='boolean'
defaultvalue=False
description='When True, use Unicode characters when outputting values, and displaying widgets at the console.'
module=astropy
value=False
"""
if name is None:
print(self)
else:
try:
print(type(self).__dict__[name])
except KeyError:
raise KeyError(
f"'{name}' is not among configuration items {tuple(self)}"
) from None
[docs]
def set_temp(self, attr, value):
"""
Temporarily set a configuration value.
Parameters
----------
attr : str
Configuration item name
value : object
The value to set temporarily.
Examples
--------
>>> import astropy
>>> with astropy.conf.set_temp('use_color', False):
... pass
... # console output will not contain color
>>> # console output contains color again...
"""
if hasattr(self, attr):
return self.__class__.__dict__[attr].set_temp(value)
raise AttributeError(f"No configuration parameter '{attr}'")
[docs]
def reload(self, attr=None):
"""
Reload a configuration item from the configuration file.
Parameters
----------
attr : str, optional
The name of the configuration parameter to reload. If not
provided, reload all configuration parameters.
"""
if attr is not None:
if hasattr(self, attr):
return self.__class__.__dict__[attr].reload()
raise AttributeError(f"No configuration parameter '{attr}'")
for item in self.values():
item.reload()
[docs]
def reset(self, attr=None):
"""
Reset a configuration item to its default.
Parameters
----------
attr : str, optional
The name of the configuration parameter to reload. If not
provided, reset all configuration parameters.
"""
if attr is not None:
if hasattr(self, attr):
prop = self.__class__.__dict__[attr]
prop.set(prop.defaultvalue)
return
raise AttributeError(f"No configuration parameter '{attr}'")
for item in self.values():
item.set(item.defaultvalue)
[docs]
class ConfigItem:
"""
A setting and associated value stored in a configuration file.
These objects should be created as members of
`ConfigNamespace` subclasses, for example::
class _Conf(config.ConfigNamespace):
unicode_output = config.ConfigItem(
False,
'Use Unicode characters when outputting values, and writing widgets '
'to the console.')
conf = _Conf()
Parameters
----------
defaultvalue : object, optional
The default value for this item. If this is a list of strings, this
item will be interpreted as an 'options' value - this item must be one
of those values, and the first in the list will be taken as the default
value.
description : str or None, optional
A description of this item (will be shown as a comment in the
configuration file)
cfgtype : str or None, optional
A type specifier like those used as the *values* of a particular key
in a ``configspec`` file of ``configobj``. If None, the type will be
inferred from the default value.
module : str or None, optional
The full module name that this item is associated with. The first
element (e.g. 'astropy' if this is 'astropy.config.configuration')
will be used to determine the name of the configuration file, while
the remaining items determine the section. If None, the package will be
inferred from the package within which this object's initializer is
called.
aliases : str, or list of str, optional
The deprecated location(s) of this configuration item. If the
config item is not found at the new location, it will be
searched for at all of the old locations.
Raises
------
RuntimeError
If ``module`` is `None`, but the module this item is created from
cannot be determined.
"""
# this is used to make validation faster so a Validator object doesn't
# have to be created every time
_validator = validate.Validator()
cfgtype = None
"""
A type specifier like those used as the *values* of a particular key in a
``configspec`` file of ``configobj``.
"""
rootname = "astropy"
"""
Rootname sets the base path for all config files.
"""
def __init__(
self, defaultvalue="", description=None, cfgtype=None, module=None, aliases=None
):
from astropy.utils import isiterable
if module is None:
module = find_current_module(2)
if module is None:
msg1 = "Cannot automatically determine get_config module, "
msg2 = "because it is not called from inside a valid module"
raise RuntimeError(msg1 + msg2)
else:
module = module.__name__
self.module = module
self.description = description
self.__doc__ = description
# now determine cfgtype if it is not given
if cfgtype is None:
if isiterable(defaultvalue) and not isinstance(defaultvalue, str):
# it is an options list
dvstr = [str(v) for v in defaultvalue]
cfgtype = "option(" + ", ".join(dvstr) + ")"
defaultvalue = dvstr[0]
elif isinstance(defaultvalue, bool):
cfgtype = "boolean"
elif isinstance(defaultvalue, int):
cfgtype = "integer"
elif isinstance(defaultvalue, float):
cfgtype = "float"
elif isinstance(defaultvalue, str):
cfgtype = "string"
defaultvalue = str(defaultvalue)
self.cfgtype = cfgtype
self._validate_val(defaultvalue)
self.defaultvalue = defaultvalue
if aliases is None:
self.aliases = []
elif isinstance(aliases, str):
self.aliases = [aliases]
else:
self.aliases = aliases
def __set__(self, obj, value):
return self.set(value)
def __get__(self, obj, objtype=None):
if obj is None:
return self
return self()
[docs]
def set(self, value):
"""
Sets the current value of this ``ConfigItem``.
This also updates the comments that give the description and type
information.
Parameters
----------
value
The value this item should be set to.
Raises
------
TypeError
If the provided ``value`` is not valid for this ``ConfigItem``.
"""
try:
value = self._validate_val(value)
except validate.ValidateError as e:
raise TypeError(
f"Provided value for configuration item {self.name} not valid:"
f" {e.args[0]}"
)
sec = get_config(self.module, rootname=self.rootname)
sec[self.name] = value
[docs]
@contextmanager
def set_temp(self, value):
"""
Sets this item to a specified value only inside a with block.
Use as::
ITEM = ConfigItem('ITEM', 'default', 'description')
with ITEM.set_temp('newval'):
#... do something that wants ITEM's value to be 'newval' ...
print(ITEM)
# ITEM is now 'default' after the with block
Parameters
----------
value
The value to set this item to inside the with block.
"""
initval = self()
self.set(value)
try:
yield
finally:
self.set(initval)
[docs]
def reload(self):
"""Reloads the value of this ``ConfigItem`` from the relevant
configuration file.
Returns
-------
val : object
The new value loaded from the configuration file.
"""
self.set(self.defaultvalue)
baseobj = get_config(self.module, True, rootname=self.rootname)
secname = baseobj.name
cobj = baseobj
# a ConfigObj's parent is itself, so we look for the parent with that
while cobj.parent is not cobj:
cobj = cobj.parent
newobj = configobj.ConfigObj(cobj.filename, interpolation=False)
if secname is not None:
if secname not in newobj:
return baseobj.get(self.name)
newobj = newobj[secname]
if self.name in newobj:
baseobj[self.name] = newobj[self.name]
return baseobj.get(self.name)
def __repr__(self):
return (
f"<{self.__class__.__name__}: name={self.name!r} value={self()!r} at"
f" 0x{id(self):x}>"
)
def __str__(self):
return "\n".join(
(
f"{self.__class__.__name__}: {self.name}",
f" cfgtype={self.cfgtype!r}",
f" defaultvalue={self.defaultvalue!r}",
f" description={self.description!r}",
f" module={self.module}",
f" value={self()!r}",
)
)
[docs]
def __call__(self):
"""Returns the value of this ``ConfigItem``.
Returns
-------
val : object
This item's value, with a type determined by the ``cfgtype``
attribute.
Raises
------
TypeError
If the configuration value as stored is not this item's type.
"""
def section_name(section):
if section == "":
return "at the top-level"
else:
return f"in section [{section}]"
options = []
sec = get_config(self.module, rootname=self.rootname)
if self.name in sec:
options.append((sec[self.name], self.module, self.name))
for alias in self.aliases:
module, name = alias.rsplit(".", 1)
sec = get_config(module, rootname=self.rootname)
if "." in module:
filename, module = module.split(".", 1)
else:
filename = module
module = ""
if name in sec:
if "." in self.module:
new_module = self.module.split(".", 1)[1]
else:
new_module = ""
warn(
f"Config parameter '{name}' {section_name(module)} of the file"
f" '{get_config_filename(filename, rootname=self.rootname)}' is"
f" deprecated. Use '{self.name}'"
f" {section_name(new_module)} instead.",
AstropyDeprecationWarning,
)
options.append((sec[name], module, name))
if len(options) == 0:
self.set(self.defaultvalue)
options.append((self.defaultvalue, None, None))
if len(options) > 1:
filename, sec = self.module.split(".", 1)
warn(
f"Config parameter '{self.name}' {section_name(sec)} of the file"
f" '{get_config_filename(filename, rootname=self.rootname)}' is given"
" by more than one alias"
f" ({', '.join(['.'.join(x[1:3]) for x in options if x[1] is not None])})."
" Using the first.",
AstropyDeprecationWarning,
)
val = options[0][0]
try:
return self._validate_val(val)
except validate.ValidateError as e:
raise TypeError(f"Configuration value not valid: {e.args[0]}")
def _validate_val(self, val):
"""Validates the provided value based on cfgtype and returns the
type-cast value.
throws the underlying configobj exception if it fails
"""
# note that this will normally use the *class* attribute `_validator`,
# but if some arcane reason is needed for making a special one for an
# instance or sub-class, it will be used
return self._validator.check(self.cfgtype, val)
# this dictionary stores the primary copy of the ConfigObj's for each
# root package
_cfgobjs = {}
def get_config_filename(packageormod=None, rootname=None):
"""
Get the filename of the config file associated with the given
package or module.
"""
cfg = get_config(packageormod, rootname=rootname)
while cfg.parent is not cfg:
cfg = cfg.parent
return cfg.filename
# This is used by testing to override the config file, so we can test
# with various config files that exercise different features of the
# config system.
_override_config_file = None
[docs]
def get_config(packageormod=None, reload=False, rootname=None):
"""Gets the configuration object or section associated with a particular
package or module.
Parameters
----------
packageormod : str or None
The package for which to retrieve the configuration object. If a
string, it must be a valid package name, or if ``None``, the package from
which this function is called will be used.
reload : bool, optional
Reload the file, even if we have it cached.
rootname : str or None
Name of the root configuration directory. If ``None`` and
``packageormod`` is ``None``, this defaults to be the name of
the package from which this function is called. If ``None`` and
``packageormod`` is not ``None``, this defaults to ``astropy``.
Returns
-------
cfgobj : ``configobj.ConfigObj`` or ``configobj.Section``
If the requested package is a base package, this will be the
``configobj.ConfigObj`` for that package, or if it is a subpackage or
module, it will return the relevant ``configobj.Section`` object.
Raises
------
RuntimeError
If ``packageormod`` is `None`, but the package this item is created
from cannot be determined.
"""
if packageormod is None:
packageormod = find_current_module(2)
if packageormod is None:
msg1 = "Cannot automatically determine get_config module, "
msg2 = "because it is not called from inside a valid module"
raise RuntimeError(msg1 + msg2)
else:
packageormod = packageormod.__name__
_autopkg = True
else:
_autopkg = False
packageormodspl = packageormod.split(".")
pkgname = packageormodspl[0]
secname = ".".join(packageormodspl[1:])
if rootname is None:
if _autopkg:
rootname = pkgname
else:
rootname = "astropy" # so we don't break affiliated packages
cobj = _cfgobjs.get(pkgname)
if cobj is None or reload:
cfgfn = None
try:
# This feature is intended only for use by the unit tests
if _override_config_file is not None:
cfgfn = Path(_override_config_file)
else:
cfgfn = (
get_config_dir_path(rootname=rootname)
.joinpath(pkgname)
.with_suffix(".cfg")
)
cobj = configobj.ConfigObj(str(cfgfn), interpolation=False)
except OSError:
# This can happen when HOME is not set
cobj = configobj.ConfigObj(interpolation=False)
# This caches the object, so if the file becomes accessible, this
# function won't see it unless the module is reloaded
_cfgobjs[pkgname] = cobj
if secname: # not the root package
if secname not in cobj:
cobj[secname] = {}
return cobj[secname]
else:
return cobj
[docs]
def generate_config(pkgname="astropy", filename=None, verbose=False):
"""Generates a configuration file, from the list of `ConfigItem`
objects for each subpackage.
.. versionadded:: 4.1
Parameters
----------
pkgname : str or None
The package for which to retrieve the configuration object.
filename : str or file-like or None
If None, the default configuration path is taken from `get_config`.
"""
if verbose:
verbosity = nullcontext
filter_warnings = AstropyDeprecationWarning
else:
verbosity = silence
filter_warnings = Warning
package = importlib.import_module(pkgname)
with verbosity(), warnings.catch_warnings():
warnings.simplefilter("ignore", category=filter_warnings)
for mod in pkgutil.walk_packages(
path=package.__path__, prefix=package.__name__ + "."
):
if mod.module_finder.path.endswith(("test", "tests")) or mod.name.endswith(
"setup_package"
):
# Skip test and setup_package modules
continue
if mod.name.split(".")[-1].startswith("_"):
# Skip private modules
continue
with contextlib.suppress(ImportError):
importlib.import_module(mod.name)
wrapper = TextWrapper(initial_indent="## ", subsequent_indent="## ", width=78)
if filename is None:
filename = get_config_filename(pkgname)
with contextlib.ExitStack() as stack:
if isinstance(filename, (str, os.PathLike)):
fp = stack.enter_context(open(filename, "w"))
else:
# assume it's a file object, or io.StringIO
fp = filename
# Parse the subclasses, ordered by their module name
subclasses = ConfigNamespace.__subclasses__()
processed = set()
for conf in sorted(subclasses, key=lambda x: x.__module__):
mod = conf.__module__
# Skip modules for other packages, e.g. astropy modules that
# would be imported when running the function for astroquery.
if mod.split(".")[0] != pkgname:
continue
# Check that modules are not processed twice, which can happen
# when they are imported in another module.
if mod in processed:
continue
else:
processed.add(mod)
print_module = True
for item in conf().values():
if print_module:
# If this is the first item of the module, we print the
# module name, but not if this is the root package...
if item.module != pkgname:
modname = item.module.replace(f"{pkgname}.", "")
fp.write(f"[{modname}]\n\n")
print_module = False
fp.write(wrapper.fill(item.description) + "\n")
if isinstance(item.defaultvalue, (tuple, list)):
if len(item.defaultvalue) == 0:
fp.write(f"# {item.name} = ,\n\n")
elif len(item.defaultvalue) == 1:
fp.write(f"# {item.name} = {item.defaultvalue[0]},\n\n")
else:
fp.write(
f"# {item.name} ="
f' {",".join(map(str, item.defaultvalue))}\n\n'
)
else:
fp.write(f"# {item.name} = {item.defaultvalue}\n\n")
[docs]
def reload_config(packageormod=None, rootname=None):
"""Reloads configuration settings from a configuration file for the root
package of the requested package/module.
This overwrites any changes that may have been made in `ConfigItem`
objects. This applies for any items that are based on this file, which
is determined by the *root* package of ``packageormod``
(e.g. ``'astropy.cfg'`` for the ``'astropy.config.configuration'``
module).
Parameters
----------
packageormod : str or None
The package or module name - see `get_config` for details.
rootname : str or None
Name of the root configuration directory - see `get_config`
for details.
"""
sec = get_config(packageormod, True, rootname=rootname)
# look for the section that is its own parent - that's the base object
while sec.parent is not sec:
sec = sec.parent
sec.reload()
def is_unedited_config_file(content, template_content=None):
"""
Determines if a config file can be safely replaced because it doesn't
actually contain any meaningful content, i.e. if it contains only comments
or is completely empty.
"""
buffer = io.StringIO(content)
raw_cfg = configobj.ConfigObj(buffer, interpolation=True)
# If any of the items is set, return False
return not any(len(v) > 0 for v in raw_cfg.values())
[docs]
def create_config_file(pkg, rootname="astropy", overwrite=False):
"""
Create the default configuration file for the specified package.
If the file already exists, it is updated only if it has not been
modified. Otherwise the ``overwrite`` flag is needed to overwrite it.
Parameters
----------
pkg : str
The package to be updated.
rootname : str
Name of the root configuration directory.
overwrite : bool
Force updating the file if it already exists.
Returns
-------
updated : bool
If the profile was updated, `True`, otherwise `False`.
"""
# local import to prevent using the logger before it is configured
from astropy.logger import log
cfgfn = Path(get_config_filename(pkg, rootname=rootname))
# generate the default config template
template_content = io.StringIO()
generate_config(pkg, template_content)
template_content.seek(0)
template_content = template_content.read()
doupdate = True
# if the file already exists, check that it has not been modified
if cfgfn is not None and cfgfn.is_file():
with open(cfgfn, encoding="latin-1") as fd:
content = fd.read()
doupdate = is_unedited_config_file(content, template_content)
if doupdate or overwrite:
with open(cfgfn, "w", encoding="latin-1") as fw:
fw.write(template_content)
log.info(f"The configuration file has been successfully written to {cfgfn}")
return True
elif not doupdate:
log.warning(
"The configuration file already exists and seems to "
"have been customized, so it has not been updated. "
"Use overwrite=True if you really want to update it."
)
return False
