Merge branch 'unicodeheaders' of https://github.com/mwalling/tablib into develop

tablib/core.py

@@ -162,7 +162,7 @@ class Dataset(object):
 
 
     def __getitem__(self, key):
-        if isinstance(key, str):
+        if isinstance(key, str) or isinstance(key, unicode):
             if key in self.headers:
                 pos = self.headers.index(key) # get 'key' index from each data
                 return [row[pos] for row in self._data]
@@ -182,7 +182,7 @@ class Dataset(object):
 
 
     def __delitem__(self, key):
-        if isinstance(key, str):
+        if isinstance(key, str) or isinstance(key, unicode):
 
             if key in self.headers:
 
@@ -741,7 +741,7 @@ class Dataset(object):
         sorted.
         """
 
-        if isinstance(col, str):
+        if isinstance(col, str) or isinstance(col, unicode):
 
             if not self.headers:
                 raise HeadersNeeded