Source code for wabisabi.default_parameter_change

"""
As this library is still in early development, the API might change.
I suggest you vendor this so that you don't create conflicts if other
libraries decide to use an older, incompatible version

If you are shipping python source code, then I've included the license
at the bottom of this file to make your life easier.
"""

from packaging.version import Version
from functools import wraps
import inspect

from warnings import warn

from .merge_docstrings import merge_docstrings


[docs]def default_parameter_change(version, old_kwargs, library_name, current_library_version): """Deprecates a default value for a kwarg. If the software version is greater or equal to that of ``version``, this decorator returns the original function without any modifications. If the user doesn't specify a parameter that will change default values, it will issue a ``FutureWarning`` pointing to the line of his code, in a single warning for all changes in the default parameters. It also modifies the ``__signature__`` of the function so that the function appears to have the default parameters to whatever the default values are in the current version of the function. Finally, if a docstring is provided, it appends a warning message compatible numpydoc. Parameters ---------- version: version-like The version in which the parameter will take the new default value. If the software version reaches this value, the new default will be taken on without warning. old_kwargs: The list of keyword arguments, with their old default values specified, as a dictionary. You should be able to copy paste your old keyword arguments and put then in a `dict`. library_name : str The human readable name for your library. current_library_version : version-like The current version of your library. Examples -------- >>> @default_parameter_change('0.16', doc(this='tim')) ... def foo(this='foo', bar='zip'): ... '''Prints your parameter. ... ... **This function has a depeprecation decorator set to '0.16'** ... ... Parameters ... ---------- ... this : str ... This is the string parameter that should be printed ... ... ''' ... print(bar) ... return this """ def the_decorator(func): if Version(current_library_version) >= Version(version): return func new_signature = inspect.signature(func) base_message = ('In release {version} of {module}, the function ' '``{funcname}`` ' 'will have new default parameters. To avoid this ' 'warning specify the value of all listed arguments.' '\n\n'.format(version=version, module=library_name, funcname=func.__name__)) old_parameters = [ inspect.Parameter( key, param.kind, default=param.default if key not in old_kwargs else old_kwargs[key]) for key, param in new_signature.parameters.items()] func_args = inspect.getfullargspec(func).args old_signature = new_signature.replace(parameters=old_parameters) @wraps(func) def wrapper(*args, **kwargs): issue_warning = False message = base_message for key, old_value in old_kwargs.items(): # Check if the argument was provided as a # positional argument if (new_signature.parameters[key].kind is inspect._POSITIONAL_OR_KEYWORD): arg_pos = func_args.index(key) if len(args) > arg_pos: continue # check if it was provided as a kwarg if key in kwargs: continue new_value = new_signature.parameters[key].default message = ( f'{message} The default value of ``{key}`` ' f'will be changed from ``{repr(old_value)}`` to ' f'``{repr(new_value)}``. ' '\n' ) kwargs[key] = old_value issue_warning = True if issue_warning: warn(message, FutureWarning, stacklevel=2) return func(*args, **kwargs) wrapper.__signature__ = old_signature # If the wrapper doesn't have a doc string, don't bother adding one. if wrapper.__doc__ is None: return wrapper doc_deprecated_kwargs = '' # Iterating through a list is tedius, though it is the only way to # ensure things stay in order in python <=3.6 for param in old_parameters: key = param.name if key not in old_kwargs: continue old_value = param.default new_value = new_signature.parameters[key].default doc_deprecated_kwargs = ( f'{doc_deprecated_kwargs} `{key}` : ' f'`{repr(old_value)}` -> `{repr(new_value)}`' '\n\n' ) warnings_string = f""" Warns ----- FutureWarning In release {version} of {library_name}, this function will take on new default value(s) for the following keyword argument(s): """ + doc_deprecated_kwargs + """ To avoid this warning in your code, specify the value of all listed keyword arguments. """ wrapper.__doc__ = merge_docstrings(wrapper, warnings_string) return wrapper return the_decorator
""" BSD 3-Clause License Copyright (c) 2018, Mark Harfouche All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. """