Fixed database typo and removed unnecessary class identifier.

venv/Lib/site-packages/scipy/_lib/_gcutils.py

@@ -0,0 +1,105 @@
+"""
+Module for testing automatic garbage collection of objects
+
+.. autosummary::
+   :toctree: generated/
+
+   set_gc_state - enable or disable garbage collection
+   gc_state - context manager for given state of garbage collector
+   assert_deallocated - context manager to check for circular references on object
+
+"""
+import weakref
+import gc
+import sys
+
+from contextlib import contextmanager
+
+__all__ = ['set_gc_state', 'gc_state', 'assert_deallocated']
+
+
+IS_PYPY = '__pypy__' in sys.modules
+
+
+class ReferenceError(AssertionError):
+    pass
+
+
+def set_gc_state(state):
+    """ Set status of garbage collector """
+    if gc.isenabled() == state:
+        return
+    if state:
+        gc.enable()
+    else:
+        gc.disable()
+
+
+@contextmanager
+def gc_state(state):
+    """ Context manager to set state of garbage collector to `state`
+
+    Parameters
+    ----------
+    state : bool
+        True for gc enabled, False for disabled
+
+    Examples
+    --------
+    >>> with gc_state(False):
+    ...     assert not gc.isenabled()
+    >>> with gc_state(True):
+    ...     assert gc.isenabled()
+    """
+    orig_state = gc.isenabled()
+    set_gc_state(state)
+    yield
+    set_gc_state(orig_state)
+
+
+@contextmanager
+def assert_deallocated(func, *args, **kwargs):
+    """Context manager to check that object is deallocated
+
+    This is useful for checking that an object can be freed directly by
+    reference counting, without requiring gc to break reference cycles.
+    GC is disabled inside the context manager.
+
+    This check is not available on PyPy.
+
+    Parameters
+    ----------
+    func : callable
+        Callable to create object to check
+    \\*args : sequence
+        positional arguments to `func` in order to create object to check
+    \\*\\*kwargs : dict
+        keyword arguments to `func` in order to create object to check
+
+    Examples
+    --------
+    >>> class C(object): pass
+    >>> with assert_deallocated(C) as c:
+    ...     # do something
+    ...     del c
+
+    >>> class C(object):
+    ...     def __init__(self):
+    ...         self._circular = self # Make circular reference
+    >>> with assert_deallocated(C) as c: #doctest: +IGNORE_EXCEPTION_DETAIL
+    ...     # do something
+    ...     del c
+    Traceback (most recent call last):
+        ...
+    ReferenceError: Remaining reference(s) to object
+    """
+    if IS_PYPY:
+        raise RuntimeError("assert_deallocated is unavailable on PyPy")
+
+    with gc_state(False):
+        obj = func(*args, **kwargs)
+        ref = weakref.ref(obj)
+        yield obj
+        del obj
+        if ref() is not None:
+            raise ReferenceError("Remaining reference(s) to object")