From 387fb0cc96cbadbcf5a261553ec0a0ff38e0568c Mon Sep 17 00:00:00 2001
From: Raymond Hettinger <raymond.hettinger@gmail.com>
Date: Wed, 14 Dec 2022 11:30:00 +0200
Subject: [PATCH 1/4] Set default lamb to one.

---
 Doc/library/random.rst  | 5 ++++-
 Lib/random.py           | 2 +-
 Lib/test/test_random.py | 1 +
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/Doc/library/random.rst b/Doc/library/random.rst
index 669204ba65b77e..be5e995e7f0ce8 100644
--- a/Doc/library/random.rst
+++ b/Doc/library/random.rst
@@ -320,7 +320,7 @@ be found in any statistics text.
    ``beta > 0``. Returned values range between 0 and 1.
 
 
-.. function:: expovariate(lambd)
+.. function:: expovariate(lambd = 1.0)
 
    Exponential distribution.  *lambd* is 1.0 divided by the desired
    mean.  It should be nonzero.  (The parameter would be called
@@ -328,6 +328,9 @@ be found in any statistics text.
    range from 0 to positive infinity if *lambd* is positive, and from
    negative infinity to 0 if *lambd* is negative.
 
+   .. versionchanged:: 3.12
+      Added the default value for `lambd`.
+
 
 .. function:: gammavariate(alpha, beta)
 
diff --git a/Lib/random.py b/Lib/random.py
index c70294ee0cbf08..e60b7294b6dd6a 100644
--- a/Lib/random.py
+++ b/Lib/random.py
@@ -577,7 +577,7 @@ def lognormvariate(self, mu, sigma):
         """
         return _exp(self.normalvariate(mu, sigma))
 
-    def expovariate(self, lambd):
+    def expovariate(self, lambd=1.0):
         """Exponential distribution.
 
         lambd is 1.0 divided by the desired mean.  It should be
diff --git a/Lib/test/test_random.py b/Lib/test/test_random.py
index 1e825c3572d20a..67de54c7db8b13 100644
--- a/Lib/test/test_random.py
+++ b/Lib/test/test_random.py
@@ -988,6 +988,7 @@ def test_zeroinputs(self):
         g.random = x[:].pop; g.uniform(1,10)
         g.random = x[:].pop; g.paretovariate(1.0)
         g.random = x[:].pop; g.expovariate(1.0)
+        g.random = x[:].pop; g.expovariate()
         g.random = x[:].pop; g.weibullvariate(1.0, 1.0)
         g.random = x[:].pop; g.vonmisesvariate(1.0, 1.0)
         g.random = x[:].pop; g.normalvariate(0.0, 1.0)

From b72f1c4b1ebee6ed72da4966c4574ac9e3cffcf6 Mon Sep 17 00:00:00 2001
From: Raymond Hettinger <raymond.hettinger@gmail.com>
Date: Wed, 14 Dec 2022 11:46:03 +0200
Subject: [PATCH 2/4] Add blurb

---
 .../next/Library/2022-12-14-11-45-38.gh-issue-100234.kn6yWV.rst | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2022-12-14-11-45-38.gh-issue-100234.kn6yWV.rst

diff --git a/Misc/NEWS.d/next/Library/2022-12-14-11-45-38.gh-issue-100234.kn6yWV.rst b/Misc/NEWS.d/next/Library/2022-12-14-11-45-38.gh-issue-100234.kn6yWV.rst
new file mode 100644
index 00000000000000..e8920afbf12558
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2022-12-14-11-45-38.gh-issue-100234.kn6yWV.rst
@@ -0,0 +1,2 @@
+Set a default value of 1.0 for the `lambd` parameter in
+random.expovariate().

From 017a7939ccee61a678b807a262a7dab6eb8de7ad Mon Sep 17 00:00:00 2001
From: Raymond Hettinger <raymond.hettinger@gmail.com>
Date: Wed, 14 Dec 2022 12:09:24 +0200
Subject: [PATCH 3/4] Fix markup

---
 Doc/library/random.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Doc/library/random.rst b/Doc/library/random.rst
index be5e995e7f0ce8..d944518a7909bc 100644
--- a/Doc/library/random.rst
+++ b/Doc/library/random.rst
@@ -329,7 +329,7 @@ be found in any statistics text.
    negative infinity to 0 if *lambd* is negative.
 
    .. versionchanged:: 3.12
-      Added the default value for `lambd`.
+      Added the default value for ``lambd``.
 
 
 .. function:: gammavariate(alpha, beta)

From c49e1b7855e25b7b064e84da663f9023177e04df Mon Sep 17 00:00:00 2001
From: Raymond Hettinger <raymond.hettinger@gmail.com>
Date: Wed, 14 Dec 2022 12:29:44 +0200
Subject: [PATCH 4/4] Fix markup

---
 .../next/Library/2022-12-14-11-45-38.gh-issue-100234.kn6yWV.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Misc/NEWS.d/next/Library/2022-12-14-11-45-38.gh-issue-100234.kn6yWV.rst b/Misc/NEWS.d/next/Library/2022-12-14-11-45-38.gh-issue-100234.kn6yWV.rst
index e8920afbf12558..6d9b909d874b34 100644
--- a/Misc/NEWS.d/next/Library/2022-12-14-11-45-38.gh-issue-100234.kn6yWV.rst
+++ b/Misc/NEWS.d/next/Library/2022-12-14-11-45-38.gh-issue-100234.kn6yWV.rst
@@ -1,2 +1,2 @@
-Set a default value of 1.0 for the `lambd` parameter in
+Set a default value of 1.0 for the ``lambd`` parameter in
 random.expovariate().