From 30ec076b486500d538ea47d26a82934305a1d147 Mon Sep 17 00:00:00 2001
From: Pip Liggins <philippa.liggins@dtc.ox.ac.uk>
Date: Mon, 9 Oct 2023 18:10:03 +0100
Subject: [PATCH] transformations: add Percentage (#88)

---
 adtl/transformations.py       | 13 +++++++++++++
 tests/test_transformations.py | 16 ++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/adtl/transformations.py b/adtl/transformations.py
index 99db47b..afc1331 100644
--- a/adtl/transformations.py
+++ b/adtl/transformations.py
@@ -98,6 +98,19 @@ def getFloat(
         return value
 
 
+def Percentage(value: float):
+    "transform a decimal into a percentage"
+    try:
+        value = float(value)
+    except (ValueError, TypeError):
+        return value
+
+    if value > 1:
+        return value
+
+    return value * 100
+
+
 def yearsElapsed(
     birthdate: str,
     currentdate: str,
diff --git a/tests/test_transformations.py b/tests/test_transformations.py
index d77283c..384458c 100644
--- a/tests/test_transformations.py
+++ b/tests/test_transformations.py
@@ -44,6 +44,22 @@ def test_wordSubstituteSet_error():
         transform.wordSubstituteSet("value", [20, 30])
 
 
+@pytest.mark.parametrize(
+    "test_value, expected",
+    [
+        (0.1, 10),
+        (1, 100),
+        (5, 5),
+        ("0.5", 50),
+        ("five", "five"),
+        ("", ""),
+        (None, None),
+    ],
+)
+def test_Percentage(test_value, expected):
+    assert transform.Percentage(test_value) == expected
+
+
 @pytest.mark.parametrize(
     "test_date_birth, test_date_current, epoch, expected",
     [