weakreflist

A WeakList class for storing objects using weak references in a list

Table of Contents

• Installation
• Usage
• Development
• Contributors

Installation

Install it from PyPi:

pip install weakreflist

or from Github:

git clone [email protected]:apieum/weakreflist.git
cd weakreflist
python setup.py install

Usage

WeakList provides the same methods as the built-in list but will remove any weakref-compatible objects that are released by the garbage collector.

Example for CPython:

from weakreflist import WeakList

class A(object):
    """weakrefs don't function directly on object()"""

objectA = A()
my_list = WeakList([objectA])
assert len(my_list) == 1
del objectA
assert len(my_list) == 0 # objectA removed from list

Note:

Pypy has a different implementation of garbage collection which changes some behavior of weakref. This may be true in other 3^rd-party compilers such as Jython and Cython. Some interactive interpreters, like IPython, may also delay calls to gc.

Due to this, you will need to explicitly call gc.collect() which has a negative impact on performance!

Example for other Python implementations

from weakreflist import WeakList
import gc

class A(object):
    """weakrefs don't function directly on object()"""

objectA = A()
my_list = WeakList([objectA])
assert len(my_list) == 1
del objectA

assert len(my_list) == 1 # gc did not run
gc.collect() # must be called explicitly
assert len(my_list) == 0

Development

Your feedback, code review, improvements, bug reports, and help to document is appreciated. You can contact me by email: apieum [at] gmail [dot] com

Setup

Install recommended packages for running tests:

pip install -r dev-requirements.txt

Note:

Sometimes --spec-color doesn't function. This can potentially be fixed by the following:

1. Uninstall nosespec and nosecolor
2. Reinstall nosecolor alone
3. Reinstall nosespec

Be certain to reinstall them separately and in the order given, otherwise you will continue to experience the same issue!

Run tests

git clone [email protected]:apieum/weakreflist.git
cd weakreflist
nosetests --with-spec --spec-color ./weakreflist
# or with watch
# nosetests --with-spec --spec-color --with-watch ./weakreflist

Contributors

Thanks to BoonsNaibot for the following contributions:

• extended slicing support
• __reversed__, count, extend, and insert methods.