From c8d6ce5708b1e3675e15e4b73302562ae47e0442 Mon Sep 17 00:00:00 2001
From: Akash <ua04012007@gmail.com>
Date: Tue, 11 Aug 2026 22:11:48 +0530
Subject: [PATCH 1/3] Add harmonic mean algorithm

---
 maths/harmonic_mean.py | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 maths/harmonic_mean.py

diff --git a/maths/harmonic_mean.py b/maths/harmonic_mean.py
new file mode 100644
index 000000000000..91e63ab91138
--- /dev/null
+++ b/maths/harmonic_mean.py
@@ -0,0 +1,33 @@
+from __future__ import annotations
+
+
+def harmonic_mean(numbers: list[int | float]) -> float:
+    """
+    Return the harmonic mean of a sequence of numbers.
+
+    >>> harmonic_mean([1, 2, 4])
+    1.7142857142857142
+    >>> harmonic_mean([2, 2, 2])
+    2.0
+    >>> harmonic_mean([])
+    Traceback (most recent call last):
+    ...
+    ValueError: harmonic_mean() arg is an empty sequence
+    >>> harmonic_mean([1, 0, 2])
+    Traceback (most recent call last):
+    ...
+    ValueError: harmonic mean is undefined for zero values
+    """
+    if not numbers:
+        raise ValueError("harmonic_mean() arg is an empty sequence")
+
+    if any(number == 0 for number in numbers):
+        raise ValueError("harmonic mean is undefined for zero values")
+
+    return len(numbers) / sum(1 / number for number in numbers)
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod(verbose=True)
\ No newline at end of file

From c22f999c0f29eb08ec5a22ef8d751d07a6add084 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Tue, 11 Aug 2026 16:45:56 +0000
Subject: [PATCH 2/3] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 maths/harmonic_mean.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/maths/harmonic_mean.py b/maths/harmonic_mean.py
index 91e63ab91138..95d03f81df18 100644
--- a/maths/harmonic_mean.py
+++ b/maths/harmonic_mean.py
@@ -30,4 +30,4 @@ def harmonic_mean(numbers: list[int | float]) -> float:
 if __name__ == "__main__":
     import doctest
 
-    doctest.testmod(verbose=True)
\ No newline at end of file
+    doctest.testmod(verbose=True)

From 6e06c09f07b351f0659f9ede2a442a643fb5a077 Mon Sep 17 00:00:00 2001
From: Akash <ua04012007@gmail.com>
Date: Tue, 11 Aug 2026 22:20:24 +0530
Subject: [PATCH 3/3] Add harmonic mean reference

---
 maths/harmonic_mean.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/maths/harmonic_mean.py b/maths/harmonic_mean.py
index 95d03f81df18..8bfbc486e836 100644
--- a/maths/harmonic_mean.py
+++ b/maths/harmonic_mean.py
@@ -5,6 +5,8 @@ def harmonic_mean(numbers: list[int | float]) -> float:
     """
     Return the harmonic mean of a sequence of numbers.
 
+    Reference: https://en.wikipedia.org/wiki/Harmonic_mean
+
     >>> harmonic_mean([1, 2, 4])
     1.7142857142857142
     >>> harmonic_mean([2, 2, 2])