82 lines
2.3 KiB
Python
82 lines
2.3 KiB
Python
"""
|
|
Module defining global singleton classes.
|
|
|
|
This module raises a RuntimeError if an attempt to reload it is made. In that
|
|
way the identities of the classes defined here are fixed and will remain so
|
|
even if numpy itself is reloaded. In particular, a function like the following
|
|
will still work correctly after numpy is reloaded::
|
|
|
|
def foo(arg=np._NoValue):
|
|
if arg is np._NoValue:
|
|
...
|
|
|
|
That was not the case when the singleton classes were defined in the numpy
|
|
``__init__.py`` file. See gh-7844 for a discussion of the reload problem that
|
|
motivated this module.
|
|
|
|
"""
|
|
from __future__ import division, absolute_import, print_function
|
|
|
|
__ALL__ = [
|
|
'ModuleDeprecationWarning', 'VisibleDeprecationWarning', '_NoValue'
|
|
]
|
|
|
|
|
|
# Disallow reloading this module so as to preserve the identities of the
|
|
# classes defined here.
|
|
if '_is_loaded' in globals():
|
|
raise RuntimeError('Reloading numpy._globals is not allowed')
|
|
_is_loaded = True
|
|
|
|
|
|
class ModuleDeprecationWarning(DeprecationWarning):
|
|
"""Module deprecation warning.
|
|
|
|
The nose tester turns ordinary Deprecation warnings into test failures.
|
|
That makes it hard to deprecate whole modules, because they get
|
|
imported by default. So this is a special Deprecation warning that the
|
|
nose tester will let pass without making tests fail.
|
|
|
|
"""
|
|
|
|
|
|
ModuleDeprecationWarning.__module__ = 'numpy'
|
|
|
|
|
|
class VisibleDeprecationWarning(UserWarning):
|
|
"""Visible deprecation warning.
|
|
|
|
By default, python will not show deprecation warnings, so this class
|
|
can be used when a very visible warning is helpful, for example because
|
|
the usage is most likely a user bug.
|
|
|
|
"""
|
|
|
|
|
|
VisibleDeprecationWarning.__module__ = 'numpy'
|
|
|
|
|
|
class _NoValueType(object):
|
|
"""Special keyword value.
|
|
|
|
The instance of this class may be used as the default value assigned to a
|
|
deprecated keyword in order to check if it has been given a user defined
|
|
value.
|
|
"""
|
|
__instance = None
|
|
def __new__(cls):
|
|
# ensure that only one instance exists
|
|
if not cls.__instance:
|
|
cls.__instance = super(_NoValueType, cls).__new__(cls)
|
|
return cls.__instance
|
|
|
|
# needed for python 2 to preserve identity through a pickle
|
|
def __reduce__(self):
|
|
return (self.__class__, ())
|
|
|
|
def __repr__(self):
|
|
return "<no value>"
|
|
|
|
|
|
_NoValue = _NoValueType()
|