Issue 29532: functools.partial is not compatible between 2.7 and 3.5

The code:
from functools import partial
def f(a):
    print(a)
d = {'a': 3}
g = partial(f, **d)
g()
d['a'] = 5 
g()

On python2.7, gets
3
but on python3.5, gets
5

is it a bug?

Confirmed that in Python 2.7 calling g() before and after modifying the dict prints 3 both times; calling g() before modifying the dict prints 3, then after modifying it prints 5.

Python 3.3 behaves like 2.7, so this sounds like a regression in 3.5 or maybe 3.4.

Yes, this can be considered a bug. Following patch fixes it.

patch LGTM.

Agree that this is a bug.  Patch and test looks good.

New changeset 9639e4ab6d5bd3ca0ab34fef127e9fc84b6b88b9 by GitHub in branch 'master':
bpo-29532: Altering a kwarg dictionary passed to functools.partial() (#190)
https://github.com/python/cpython/commit/9639e4ab6d5bd3ca0ab34fef127e9fc84b6b88b9

New changeset e48fd93bbb36c6d80aa4eb6af09f58c69d8cf965 by GitHub in branch '3.6':
bpo-29532: Altering a kwarg dictionary passed to functools.partial() no longer affects a partial object after creation. (#209)
https://github.com/python/cpython/commit/e48fd93bbb36c6d80aa4eb6af09f58c69d8cf965

New changeset 5010a77a4da76d8d3fd861a63a7f1ce8f0e9c520 by GitHub in branch '3.5':
[3.5] bpo-29532: Altering a kwarg dictionary passed to functools.partial() no longer affects a partial object after creation. (#222)
https://github.com/python/cpython/commit/5010a77a4da76d8d3fd861a63a7f1ce8f0e9c520

components: + Library (Lib)
versions: + Python 3.7, - Python 3.4
keywords: + patch
nosy: + serhiy.storchaka

messages: + msg287598
stage: patch review

messages: + msg287595
versions: + Python 3.4, Python 3.6