"""
A set of convenient on-demand imports
"""
# -----------------------------------------------------------------------------
# Copyright (c) 2018, yt Development Team.
#
# Distributed under the terms of the Modified BSD License.
#
# The full license is in the LICENSE file, distributed with this software.
# -----------------------------------------------------------------------------
class NotAModule(object):
"""
A class to implement an informative error message that will be outputted if
someone tries to use an on-demand import without having the requisite
package installed.
"""
def __init__(self, pkg_name):
self.pkg_name = pkg_name
self.error = ImportError(
"This functionality requires the %s "
"package to be installed." % self.pkg_name
)
def __getattr__(self, item):
raise self.error
def __call__(self, *args, **kwargs):
raise self.error
class astropy_imports(object):
_name = "astropy"
_log = None
_units = None
_version = None
@property
def log(self):
if self._log is None:
try:
from astropy import log
if log.exception_logging_enabled():
log.disable_exception_logging()
except ImportError:
log = NotAModule(self._name)
self._log = log
return self._log
@property
def units(self):
if self._units is None:
try:
from astropy import units
self.log
except ImportError:
units = NotAModule(self._name)
self._units = units
return self._units
@property
def __version__(self):
if self._version is None:
try:
import astropy
version = astropy.__version__
except ImportError:
version = NotAModule(self._name)
self._version = version
return self._version
_astropy = astropy_imports()
class h5py_imports(object):
_name = "h5py"
_File = None
_version = None
@property
def File(self):
if self._File is None:
try:
from h5py import File
except ImportError:
File = NotAModule(self._name)
self._File = File
return self._File
@property
def __version__(self):
if self._version is None:
try:
from h5py import __version__
self._version = __version__
except ImportError:
self._version = NotAModule(self._name)
return self._version
_h5py = h5py_imports()
class pint_imports(object):
_name = "pint"
_UnitRegistry = None
@property
def UnitRegistry(self):
if self._UnitRegistry is None:
try:
from pint import UnitRegistry
except ImportError:
UnitRegistry = NotAModule(self._name)
self._UnitRegistry = UnitRegistry
return self._UnitRegistry
_pint = pint_imports()
class matplotlib_imports(object):
_name = "matplotlib"
_pyplot = None
_units = None
_use = None
@property
def __version__(self):
if self._version is None:
try:
from matplotlib import __version__
self._version = __version__
except ImportError:
self._version = NotAModule(self._name)
return self._version
@property
def pyplot(self):
if self._pyplot is None:
try:
from matplotlib import pyplot
except ImportError:
pyplot = NotAModule(self._name)
self._pyplot = pyplot
return self._pyplot
@property
def units(self):
if self._units is None:
try:
from matplotlib import units
except ImportError:
units = NotAModule(self._name)
self._units = units
return self._units
@property
def use(self):
if self._use is None:
try:
from matplotlib import use
except ImportError:
use = NotAModule(self._name)
self._use = use
return self._use
_matplotlib = matplotlib_imports()
