bpo-37624: Document weight assumptions for random.choices() (GH-14855)
diff --git a/Doc/library/random.rst b/Doc/library/random.rst
index fcedba4..90b8624 100644
--- a/Doc/library/random.rst
+++ b/Doc/library/random.rst
@@ -160,7 +160,8 @@
The *weights* or *cum_weights* can use any numeric type that interoperates
with the :class:`float` values returned by :func:`random` (that includes
- integers, floats, and fractions but excludes decimals).
+ integers, floats, and fractions but excludes decimals). Weights are
+ assumed to be non-negative.
For a given seed, the :func:`choices` function with equal weighting
typically produces a different sequence than repeated calls to