From: Raymond Hettinger <rhettinger@users.noreply.github.com>
Date: Wed, 12 Mar 2025 18:25:31 +0000 (-0500)
Subject: Improve docstring for random.binomialvariate (gh-131164)
X-Git-Tag: v3.14.0a6~54
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=25f24b01e3b675c6afbb653f07034a3c9a6aee32;p=thirdparty%2FPython%2Fcpython.git

Improve docstring for random.binomialvariate (gh-131164)

Add probability distribution to the docstring
---

diff --git a/Lib/random.py b/Lib/random.py
index 1abcae77c8be..4d9a047b0279 100644
--- a/Lib/random.py
+++ b/Lib/random.py
@@ -792,12 +792,18 @@ class Random(_random.Random):
 
             sum(random() < p for i in range(n))
 
-        Returns an integer in the range:   0 <= X <= n
+        Returns an integer in the range:
+
+            0 <= X <= n
+
+        The integer is chosen with the probability:
+
+            P(X == k) = math.comb(n, k) * p ** k * (1 - p) ** (n - k)
 
         The mean (expected value) and variance of the random variable are:
 
             E[X] = n * p
-            Var[x] = n * p * (1 - p)
+            Var[X] = n * p * (1 - p)
 
         """
         # Error check inputs and handle edge cases