Added doctests for hgvs/utils/norm.py (#548)

* Added doctest for hgvs/utils/__init__.py
* Added doctest for hgvs/utils/norm.py

hgvs/utils/norm.py

@@ -12,7 +12,13 @@
 
 
 def trim_common_suffixes(strs, min_len=0):
-    """trim common suffixes"""
+    """
+    trim common suffixes
+
+    >>> trim_common_suffixes('A', 1)
+    (0, 'A')
+
+    """
 
     if len(strs) < 2:
         return 0, strs
@@ -48,7 +54,13 @@ def trim_common_prefixes(strs, min_len=0):
 
 
 def normalize_alleles_left(ref, start, stop, alleles, bound, ref_step, shuffle=True):
-    """Normalize loci by removing extraneous reference padding"""
+    """
+    Normalize loci by removing extraneous reference padding
+
+    >>> normalize_alleles_left('A', 1, 2, 'A', 1, 2)
+    shuffled_alleles(start=1, stop=2, alleles='A')
+
+    """
 
     normalized_alleles = namedtuple('shuffled_alleles', 'start stop alleles')
 
@@ -92,7 +104,13 @@ def normalize_alleles_left(ref, start, stop, alleles, bound, ref_step, shuffle=T
 
 
 def normalize_alleles_right(ref, start, stop, alleles, bound, ref_step, shuffle=True):
-    """Normalize loci by removing extraneous reference padding"""
+    """
+    Normalize loci by removing extraneous reference padding
+
+    >>> normalize_alleles_right('A', 1, 2, 'A', 1, 2)
+    shuffled_alleles(start=1, stop=2, alleles='A')
+
+    """
 
     normalized_alleles = namedtuple('shuffled_alleles', 'start stop alleles')