Merge pull request #677 from jw2013/develop

Drop the string initialization of Tree

nltk/test/tree.doctest

@@ -41,32 +41,32 @@ tree object to one of several standard tree encodings:
 
 Trees can be initialized from treebank strings:
 
-    >>> tree2 = Tree('(S (NP I) (VP (V enjoyed) (NP my cookie)))')
+    >>> tree2 = Tree.fromstring('(S (NP I) (VP (V enjoyed) (NP my cookie)))')
     >>> print(tree2)
     (S (NP I) (VP (V enjoyed) (NP my cookie)))
 
 Trees can be compared for equality:
 
-    >>> tree == Tree(str(tree))
+    >>> tree == Tree.fromstring(str(tree))
     True
-    >>> tree2 == Tree(str(tree2))
+    >>> tree2 == Tree.fromstring(str(tree2))
     True
     >>> tree == tree2
     False
-    >>> tree == Tree(str(tree2))
+    >>> tree == Tree.fromstring(str(tree2))
     False
-    >>> tree2 == Tree(str(tree))
+    >>> tree2 == Tree.fromstring(str(tree))
     False
 
-    >>> tree != Tree(str(tree))
+    >>> tree != Tree.fromstring(str(tree))
     False
-    >>> tree2 != Tree(str(tree2))
+    >>> tree2 != Tree.fromstring(str(tree2))
     False
     >>> tree != tree2
     True
-    >>> tree != Tree(str(tree2))
+    >>> tree != Tree.fromstring(str(tree2))
     True
-    >>> tree2 != Tree(str(tree))
+    >>> tree2 != Tree.fromstring(str(tree))
     True
 
     >>> tree < tree2 or tree > tree2
@@ -1075,4 +1075,3 @@ This used to discard the ``(B b)`` subtree (fixed in svn 6270):
     >>> print(Tree.fromstring('((A a) (B b))'))
     ( (A a) (B b))
 
-