# Copyright (c) 2015,2018,2019 MetPy Developers.
# Distributed under the terms of the BSD 3-Clause License.
# SPDX-License-Identifier: BSD-3-Clause
"""Collection of tools for managing the package."""
# Used to specify functions that should be exported--i.e. added to __all__
# Inspired by David Beazley and taken from python-ideas:
# https://mail.python.org/pipermail/python-ideas/2014-May/027824.html
__all__ = ('Exporter',)
class Exporter:
"""Manages exporting of symbols from the module.
Grabs a reference to `globals()` for a module and provides a decorator to add
functions and classes to `__all__` rather than requiring a separately maintained list.
Also provides a context manager to do this for instances by adding all instances added
within a block to `__all__`.
"""
def __init__(self, globls):
"""Initialize the Exporter."""
self.globls = globls
self.exports = globls.setdefault('__all__', [])
def export(self, defn):
"""Declare a function or class as exported."""
self.exports.append(defn.__name__)
return defn
def __enter__(self):
"""Start a block tracking all instances created at global scope."""
self.start_vars = set(self.globls)
def __exit__(self, exc_type, exc_val, exc_tb):
"""Exit the instance tracking block."""
self.exports.extend(set(self.globls) - self.start_vars)
del self.start_vars
[docs]def set_module(globls):
"""Set the module for all functions in ``__all__``.
This sets the ``__module__`` attribute of all items within the ``__all__`` list
for the calling module.
This supports our hoisting of functions out of individual modules, which are
considered implementation details, into the namespace of the top-level subpackage.
Parameters
----------
globls : Dict[str, object]
Mapping of all global variables for the module. This contains all needed
python special ("dunder") variables needed to be modified.
"""
for item in globls['__all__']:
obj = globls[item]
if hasattr(obj, '__module__'):
obj.__module__ = globls['__name__']