Optimization for pickling random states

-- Addresses https://github.com/numpy/numpy/issues/4763

1 files changed, 9 insertions, 1 deletions

diff --git a/numpy/random/__init__.py b/numpy/random/__init__.py
index 614b25a1c..388267c97 100644
--- a/numpy/random/__init__.py
+++ b/numpy/random/__init__.py
@@ -106,8 +106,16 @@ def __RandomState_ctor():
     """Return a RandomState instance.
 
     This function exists solely to assist (un)pickling.
+
+    Note that the state of the RandomState returned here is irrelevant, as this function's
+    entire purpose is to return a newly allocated RandomState whose state pickle can set.
+    Consequently the RandomState returned by this function is a freshly allocated copy
+    with a seed=0.
+
+    See https://github.com/numpy/numpy/issues/4763 for a detailed discussion
+
     """
-    return RandomState()
+    return RandomState(seed=0)
 
 from numpy.testing import Tester
 test = Tester().test