Initial commit

exams/grading.py

@@ -0,0 +1,28 @@
+import math
+
+
+# IELTS Academic Reading conversion commonly used for 40-question papers.
+# Scores between published boundaries are represented in 0.5-band steps.
+ACADEMIC_READING_BANDS = (
+    (39, 9.0), (37, 8.5), (35, 8.0), (33, 7.5), (30, 7.0),
+    (27, 6.5), (23, 6.0), (19, 5.5), (15, 5.0), (13, 4.5),
+    (10, 4.0), (8, 3.5), (6, 3.0), (4, 2.5), (3, 2.0),
+    (2, 1.5), (1, 1.0), (0, 0.0),
+)
+
+
+def academic_reading_band(correct, total=40):
+    """Return (band, equivalent_40_score, is_estimate) for an objective Reading score."""
+    if total <= 0:
+        return None, None, False
+    correct = max(0, min(int(correct), int(total)))
+    if total == 40:
+        equivalent = correct
+        estimated = False
+    else:
+        # Round half upward so Python's banker rounding does not disadvantage
+        # passage-sized practice scores at exact .5 boundaries.
+        equivalent = min(40, math.floor((correct * 40 / total) + 0.5))
+        estimated = True
+    band = next(band for minimum, band in ACADEMIC_READING_BANDS if equivalent >= minimum)
+    return band, equivalent, estimated