From 8c76758c320d4e9799cd8087d48eb51d2612090c Mon Sep 17 00:00:00 2001
From: ebokoo <softonus111@gmail.com>
Date: Wed, 4 Mar 2026 12:20:22 +0800
Subject: [PATCH] Add sign function to maths module

---
 maths/sign.py | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 maths/sign.py

diff --git a/maths/sign.py b/maths/sign.py
new file mode 100644
index 000000000000..b8ac801ff49f
--- /dev/null
+++ b/maths/sign.py
@@ -0,0 +1,40 @@
+"""Sign Function."""
+
+
+def sign(num: float) -> int:
+    """
+    Return the sign of a number: -1 for negative, 0 for zero, 1 for positive.
+
+    >>> sign(-5)
+    -1
+    >>> sign(0)
+    0
+    >>> sign(10)
+    1
+    >>> sign(-0.5)
+    -1
+    """
+    if num > 0:
+        return 1
+    elif num < 0:
+        return -1
+    return 0
+
+
+def test_sign():
+    """
+    >>> test_sign()
+    """
+    assert sign(-5) == -1
+    assert sign(0) == 0
+    assert sign(10) == 1
+    assert sign(-0.001) == -1
+    assert sign(0.001) == 1
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()
+    test_sign()
+    print(sign(-5))  # --> -1