Duplicate values for <gmd:distribution format> about pygeometa HOT 5 CLOSED

diff --git a/pygeometa/core.py b/pygeometa/core.py
index b23fd41..16a76bf 100644
--- a/pygeometa/core.py
+++ b/pygeometa/core.py
@@ -260,9 +260,11 @@ def render_template(mcf, schema=None, schema_local=None):
     env.filters['normalize_datestring'] = normalize_datestring
     env.filters['get_distribution_language'] = get_distribution_language
     env.filters['get_charstring'] = get_charstring
+    env.filters['get_unique_distribution_format'] = get_unique_distribution_format
     env.globals.update(zip=zip)
     env.globals.update(get_charstring=get_charstring)
     env.globals.update(normalize_datestring=normalize_datestring)
+    env.globals.update(get_unique_distribution_format=get_unique_distribution_format)
 
     try:
         LOGGER.debug('Loading template')
@@ -294,6 +296,17 @@ def get_abspath(mcf, filepath):
     return os.path.join(abspath, filepath)
 
 
+def get_unique_distribution_format(items):
+    """returns a list of dictionnaries of the unique distribution formats"""
+
+    unique_distribution_list = []
+    for k, v in items:
+        if v['format_en'] and v['format_fr'] and v['format_version']:
+            if {'format_en': v['format_en'], 'format_fr': v['format_fr'], 'format_version': v['format_version']} not in unique_distribution_list:
+                unique_distribution_list.append({'format_en': v['format_en'], 'format_fr': v['format_fr'], 'format_version': v['format_version']})
+    return unique_distribution_list
+
+
 class MCFReadError(Exception):
     """Exception stub for format reading errors"""
     pass
diff --git a/pygeometa/templates/iso19139-hnap/main.j2 b/pygeometa/templates/iso19139-hnap/main.j2
index 0058017..1ccdd47 100644
--- a/pygeometa/templates/iso19139-hnap/main.j2
+++ b/pygeometa/templates/iso19139-hnap/main.j2
@@ -476,8 +476,7 @@
   </gmd:identificationInfo>
   <gmd:distributionInfo>
     <gmd:MD_Distribution>
-      {% for k, v in record['distribution'].items() %}
-      {% if v['format_en'] and v['format_fr'] and v['format_version'] %}
+      {% for v in get_unique_distribution_format(record['distribution'].items()) %}
       <gmd:distributionFormat>
         <gmd:MD_Format>
           {{ cs.get_freetext('name', 'fra', get_charstring('format', v, 'en', 'fr')) }}
@@ -486,7 +485,6 @@
           </gmd:version>
         </gmd:MD_Format>
       </gmd:distributionFormat>
-      {% endif %}
       {% endfor %}
       <gmd:distributor>
         <gmd:MD_Distributor>

index 27ecd5d..f8faa05 100644
--- a/pygeometa/core.py
+++ b/pygeometa/core.py
@@ -145,8 +145,33 @@ def normalize_datestring(datestring, format_='default'):
     return datestring
 
 
+def prune_distribution_formats(formats):
+    """derive a unique list of distribution formats"""
+
+    counter = 0
+    formats_ = []
+
+    for k1, v1 in formats.items():
+        row = {}
+        for k2, v2 in v1.items():
+            if k2.startswith('format'):
+                row[k2] = v2
+        formats_.append(row)
+
+    num_elements = len(formats)
+
+    for f in formats_:
+        counter += 1
+        if num_elements == counter:
+            break
+        if cmp(f, formats_[counter]) == 0:
+            formats_.pop(counter)
+
+    return formats_
+
+
 def read_mcf(mcf):
-    """returns dict of YAML file from filepath"""
+    """returns dict of YAML file from filepath, string or dict"""
 
     mcf_dict = {}
 
@@ -245,12 +270,14 @@ def render_template(mcf, schema=None, schema_local=None):
 
     LOGGER.debug('Setting up template environment {}'.format(abspath))
     env = Environment(loader=FileSystemLoader([abspath, TEMPLATES]))
-    env.filters['normalize_datestring'] = normalize_datestring
-    env.filters['get_distribution_language'] = get_distribution_language
     env.filters['get_charstring'] = get_charstring
-    env.globals.update(zip=zip)
+    env.filters['get_distribution_language'] = get_distribution_language
+    env.filters['prune_distribution_formats'] = prune_distribution_formats
+    env.filters['normalize_datestring'] = normalize_datestring
     env.globals.update(get_charstring=get_charstring)
     env.globals.update(normalize_datestring=normalize_datestring)
+    env.globals.update(prune_distribution_formats=prune_distribution_formats)
+    env.globals.update(zip=zip)
 
     try:
         LOGGER.debug('Loading template')
diff --git a/pygeometa/templates/iso19139-hnap/main.j2 b/pygeometa/templates/iso19139-hnap/main.j2
index 9aa8ec7..c0aa3f3 100644
--- a/pygeometa/templates/iso19139-hnap/main.j2
+++ b/pygeometa/templates/iso19139-hnap/main.j2
@@ -476,7 +476,8 @@
   </gmd:identificationInfo>
   <gmd:distributionInfo>
     <gmd:MD_Distribution>
-      {% for k, v in record['distribution'].items() %}
+      {% set formats = prune_distribution_formats(record['distribution']) %}
+      {% for v in formats %}
       {% if v['format_en'] and v['format_fr'] and v['format_version'] %}
       <gmd:distributionFormat>
         <gmd:MD_Format>
diff --git a/pygeometa/templates/iso19139/main.j2 b/pygeometa/templates/iso19139/main.j2
index 6b3d73a..1493638 100644
--- a/pygeometa/templates/iso19139/main.j2
+++ b/pygeometa/templates/iso19139/main.j2
@@ -292,7 +292,8 @@
       </gmd:distributor>
       <gmd:transferOptions>
         <gmd:MD_DigitalTransferOptions>
-        {% for k, v in record['distribution'].items() %}
+        {% set formats = prune_distribution_formats(record['distribution']) %}
+        {% for v in formats %}
           <gmd:onLine>
             <gmd:CI_OnlineResource>
               <gmd:linkage>
diff --git a/pygeometa/templates/wmo-cmp/main.j2 b/pygeometa/templates/wmo-cmp/main.j2
index ea63535..04a2ddf 100644
--- a/pygeometa/templates/wmo-cmp/main.j2
+++ b/pygeometa/templates/wmo-cmp/main.j2
@@ -336,7 +336,8 @@
       </gmd:distributor>
       <gmd:transferOptions>
         <gmd:MD_DigitalTransferOptions>
-          {% for k, v in record['distribution'].items() %} 
+        {% set formats = prune_distribution_formats(record['distribution']) %}
+        {% for v in formats %}
           <gmd:onLine>
             <gmd:CI_OnlineResource>
               <gmd:linkage>
diff --git a/tests/run_tests.py b/tests/run_tests.py
index 29b64bb..128d3bb 100644
--- a/tests/run_tests.py
+++ b/tests/run_tests.py
@@ -53,7 +53,8 @@ from six import text_type
 import yaml
 
 from pygeometa.core import (read_mcf, pretty_print, render_template,
-                            get_charstring, get_supported_schemas)
+                            get_charstring, get_supported_schemas,
+                            prune_distribution_formats)
 
 THISDIR = os.path.dirname(os.path.realpath(__file__))
 
@@ -153,6 +154,23 @@ class PygeometaTest(unittest.TestCase):
                                 {'title_fr': 'foo', 'title_en': 'bar'}, 'fr')
         self.assertEqual(values, [None, None], 'Expected specific values')
 
+    def test_prune_distribution_formats(self):
+        """Test deriving unique distribution formats"""
+
+        formats = {
+            'wms': {
+                'format_en': 'image', 'format_fr': 'image', 'format_version': 2
+            },
+            'wfs': {
+                'format_en': 'GRIB2', 'format_fr': 'GRIB2', 'format_version': 2
+            },
+            'wcs': {
+                'format_en': 'GRIB2', 'format_fr': 'GRIB2', 'format_version': 2
+            }
+
+        new_formats = prune_distribution_formats(formats)
+
+        self.assertEqual(len(new_formats), 2,
+                         'Expected 2 unique distribution formats')
+
     def test_get_supported_schemas(self):
         """Test supported schemas"""