Karthikeyan Singaravelan <tir.kar...@gmail.com> added the comment:
https://docs.python.org/3/library/multiprocessing.html#proxy-objects > If standard (non-proxy) list or dict objects are contained in a referent, > modifications to those mutable values will not be propagated through the > manager because the proxy has no way of knowing when the values contained > within are modified. However, storing a value in a container proxy (which > triggers a __setitem__ on the proxy object) does propagate through the > manager and so to effectively modify such an item, one could re-assign the > modified value to the container proxy $ ./python.exe Python 3.8.0a2+ (heads/master:d5a551c269, Feb 26 2019, 15:49:14) [Clang 7.0.2 (clang-700.1.81)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> from multiprocessing import Manager >>> man = Manager() >>> shared_list = man.dict() >>> shared_list['a'] = list() >>> shared_list['a'].append(100) >>> shared_list <DictProxy object, typeid 'dict' at 0x1096adc50> >>> dict(shared_list) {'a': []} >>> shared_list['a'] += [1000] # Update and assign >>> dict(shared_list) {'a': [1000]} >>> shared_list['a'] += [1000] # Update and assign >>> dict(shared_list) {'a': [1000, 1000]} ---------- nosy: +pitrou, xtreak _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue36119> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
