diff --git a/numpy/core/arrayprint.py b/numpy/core/arrayprint.py index 84943cafc1de..cbe95f51b7e0 100644 --- a/numpy/core/arrayprint.py +++ b/numpy/core/arrayprint.py @@ -772,7 +772,8 @@ def recurser(index, hanging_indent, curr_width): s += hanging_indent + summary_insert + line_sep for i in range(trailing_items, 1, -1): - nested = recurser(index + (-i,), next_hanging_indent, next_width) + nested = recurser(index + (-i,), next_hanging_indent, + next_width) s += hanging_indent + nested + line_sep nested = recurser(index + (-1,), next_hanging_indent, next_width) @@ -782,12 +783,16 @@ def recurser(index, hanging_indent, curr_width): s = '[' + s[len(hanging_indent):] + ']' return s - # invoke the recursive part with an initial index and prefix - return recurser( - index=(), - hanging_indent=next_line_prefix, - curr_width=line_width) - + try: + # invoke the recursive part with an initial index and prefix + return recurser(index=(), + hanging_indent=next_line_prefix, + curr_width=line_width) + finally: + # recursive closures have a cyclic reference to themselves, which + # requires gc to collect (gh-10620). To avoid this problem, for + # performance and PyPy friendliness, we break the cycle: + recurser = None def _none_or_positive_arg(x, name): if x is None: diff --git a/numpy/core/shape_base.py b/numpy/core/shape_base.py index 65c3ed00dbd3..319c25088102 100644 --- a/numpy/core/shape_base.py +++ b/numpy/core/shape_base.py @@ -446,7 +446,13 @@ def block_recursion(arrays, depth=0): # type(arrays) is not list return atleast_nd(arrays, result_ndim) - return block_recursion(arrays) + try: + return block_recursion(arrays) + finally: + # recursive closures have a cyclic reference to themselves, which + # requires gc to collect (gh-10620). To avoid this problem, for + # performance and PyPy friendliness, we break the cycle: + block_recursion = None def block(arrays): diff --git a/numpy/core/tests/test_arrayprint.py b/numpy/core/tests/test_arrayprint.py index d4c565c570f9..88aaa34039a8 100644 --- a/numpy/core/tests/test_arrayprint.py +++ b/numpy/core/tests/test_arrayprint.py @@ -1,7 +1,7 @@ # -*- coding: utf-8 -*- from __future__ import division, absolute_import, print_function -import sys +import sys, gc import numpy as np from numpy.testing import ( @@ -355,6 +355,18 @@ def test_wide_element(self): "[ 'xxxxx']" ) + def test_refcount(self): + # make sure we do not hold references to the array due to a recursive + # closure (gh-10620) + gc.disable() + a = np.arange(2) + r1 = sys.getrefcount(a) + np.array2string(a) + np.array2string(a) + r2 = sys.getrefcount(a) + gc.collect() + gc.enable() + assert_(r1 == r2) class TestPrintOptions(object): """Test getting and setting global print options.""" diff --git a/numpy/lib/npyio.py b/numpy/lib/npyio.py index 096f1a3a4ef4..73613d2a4878 100644 --- a/numpy/lib/npyio.py +++ b/numpy/lib/npyio.py @@ -1109,6 +1109,11 @@ def tobytes_first(x, conv): finally: if fown: fh.close() + # recursive closures have a cyclic reference to themselves, which + # requires gc to collect (gh-10620). To avoid this problem, for + # performance and PyPy friendliness, we break the cycle: + flatten_dtype_internal = None + pack_items = None if X is None: X = np.array([], dtype)