human
Solve the following python programming problem given the following code:
@ cached_property 
def _pages(self) : 
    '
        Walk the page root directory and return a dict of ``{unicode path: page
        object}``.
        ' 
    def _walker() : 
        '
            Walk over directory and find all possible flatpages, i.e. files
            which end with the string or sequence given by
            ``FLATPAGES_%(name)s_EXTENSION``.
            ' 
        for (cur_path, _, filenames) in os.walk (self.root) : 
            rel_path = cur_path.replace (self.root, '').lstrip (os.sep) 
            path_prefix = (tuple (rel_path.split (os.sep)) if rel_path else ()) 
            for name in filenames : 
                if (not name.endswith (extension)) : 
                    continue 
full_name = os.path.join (cur_path, name) 
                name_without_extension = [name [: (- len (item))] for item in extension if name.endswith (item)] [0] 
                path = '/'.join ((path_prefix + (name_without_extension,))) 
                (yield (path, full_name)) 
extension = self.config ('extension') 
    if isinstance (extension, compat.string_types) : 
        if (',' in extension) : 
            extension = tuple (extension.split (',')) 
else : 
            extension = (full_name,) 
else : 
        if isinstance (extension, (list, set)) : 
            extension = tuple (extension) 
if (not isinstance (extension, tuple)) : 
        raise ValueError ('Invalid value for FlatPages extension. Should be a string or a sequence, got {0} instead: {1}'.format (type (extension).__name__, extension)) 
return dict ([(path, self._load_file (path, full_name)) for (path, full_name) in _walker ()]) 

    
    

    Fix the buggy line: extension = (full_name,)
assistant
#Here is Python code to find all possible flatpages, i.

extension = (extension,)