MetaData can be built from a mapping

Author: demianw

nibabel/cifti2/cifti2.py

@@ -109,8 +109,10 @@ class Cifti2MetaData(xml.XmlSerializable, collections.MutableMapping):
     ----------
     data : list of (name, value) tuples
     """
-    def __init__(self):
+    def __init__(self, metadata=None):
         self.data = collections.OrderedDict()
+        if metadata is not None:
+            self.update(metadata)
 
     def __getitem__(self, key):
         return self.data[key]

nibabel/cifti2/tests/test_cifti2.py

@@ -24,6 +24,12 @@ def compare_xml_leaf(str1, str2):
 
 
 def test_cifti2_metadata():
+    md = ci.Cifti2MetaData(metadata={'a': 'aval'})
+    assert_equal(len(md), 1)
+    assert_equal(list(iter(md)), ['a'])
+    assert_equal(md['a'], 'aval')
+    assert_equal(md.data, dict([('a', 'aval')]))
+
     md = ci.Cifti2MetaData()
     assert_equal(len(md), 0)
     assert_equal(list(iter(md)), [])