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# Copyright (c) 2012 - 2021, Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
#
# The full license is in the file LICENSE.txt, distributed with this software.
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''' Utilities for checking dependencies
'''
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# Boilerplate
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from __future__ import annotations
import logging # isort:skip
log = logging.getLogger(__name__)
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# Imports
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# Standard library imports
from importlib import import_module
from types import ModuleType
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# Globals and constants
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__all__ = (
'import_optional',
'import_required',
)
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# General API
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[docs]def import_optional(mod_name: str) -> ModuleType | None:
''' Attempt to import an optional dependency.
Silently returns None if the requested module is not available.
Args:
mod_name (str) : name of the optional module to try to import
Returns:
imported module or None, if import fails
'''
try:
return import_module(mod_name)
except ImportError:
pass
except Exception:
msg = f"Failed to import optional module `{mod_name}`"
log.exception(msg)
return None
[docs]def import_required(mod_name: str, error_msg: str) -> ModuleType:
''' Attempt to import a required dependency.
Raises a RuntimeError if the requested module is not available.
Args:
mod_name (str) : name of the required module to try to import
error_msg (str) : error message to raise when the module is missing
Returns:
imported module
Raises:
RuntimeError
'''
try:
return import_module(mod_name)
except ImportError as e:
raise RuntimeError(error_msg) from e
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# Dev API
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# Private API
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# Code
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