from BTreeWordFinder import * from BalancedBTree import * class BalancedBTreeWordFinder(BTreeWordFinder): '' 'binary search class implemented with a balanced binary tree; inherits from BTreeWordFinder and thus takes advantage of its methods' '' def __init__(self, file, btree=None): '' 'Builder methods' '' BTreeWordFinder.__init__(self, file, btree) @staticmethod def main(): '' 'main method version of the class for the search engine implemented with a balanced tree' '' b = BalancedBTreeWordFinder(BalancedBTreeWordFinder.askFile(), BalancedBTree()) b.findOcurrencesInFile('dictionary.txt') b.viewIndex() b.showDepth() if __name__ == "__main__": BalancedBTreeWordFinder.main()

def __str__(self): return str(self._val) # here is the error

Error:
Traceback (most recent call last): File "D:/btree-word-finder-master/btree-word-finder-master/Code_and_texts/BalancedBTreeWordFinder.py", line 20, in <module> BalancedBTreeWordFinder.main() File "D:/btree-word-finder-master/btree-word-finder-master/Code_and_texts/BalancedBTreeWordFinder.py", line 16, in main b.viewIndex() File "D:\btree-word-finder-master\btree-word-finder-master\Code_and_texts\BTreeWordFinder.py", line 48, in viewIndex self.getBTree().doinOrden() File "D:\btree-word-finder-master\btree-word-finder-master\Code_and_texts\BTree.py", line 80, in doinOrden self.inOrden(self.getRoot()) File "D:\btree-word-finder-master\btree-word-finder-master\Code_and_texts\BTree.py", line 89, in inOrden self.visit(probe) # visit mean to search on traversed left File "D:\btree-word-finder-master\btree-word-finder-master\Code_and_texts\BTree.py", line 107, in visit print(node) File "D:\btree-word-finder-master\btree-word-finder-master\Code_and_texts\Node.py", line 39, in __str__ return '%s %s %s'%(self._val) TypeError: __str__ returned non-string (type tuple)

str(sel._val) '%s %s %s'%(self._val) , return '{} {} {}'.format(self._val) and template = '{self._val}' return template.format(self) def __str__(self): return str(self._val) # here is the error