Update remap_alleles

python/tests/beagle_numba.py

@@ -130,19 +130,23 @@ def get_alleles_at_site(self, i):
 
 def remap_alleles(a):
     """
-    Helper function.
+    Helper function to map an allele encoded as a character to an integer.
 
     TODO: Move elsewhere.
+
+    :param str allele: Allele.
+    :return: Recorded allele.
+    :rtype: int
     """
     _ALLELES_ACGT = "ACGT"
-    b = np.zeros(len(a), dtype=np.int8) - 1
+    b = np.zeros(len(a), dtype=np.int8) - 1  # Encoded as missing by default
     for i in range(len(a)):
         if a[i] in [None, ""]:
             continue
         elif a[i] in _ALLELES_ACGT:
             b[i] = _ALLELES_ACGT.index(a[i])
         else:
-            raise AssertionError(f"Unrecognised character: {a[i]}")
+            raise AssertionError(f"Allele {a[i]} is not recognised.")
     return b