human
Solve the following python programming problem given the following code:
def get_children(self, obj) : 
    'Returns the child objects of a particular tvtk object in a
        dictionary, the keys are the trait names.  This is used to
        generate the tree in the browser.' 
    vtk_obj = tvtk.to_vtk (obj) 
    methods = self._get_methods (vtk_obj) 
    kids = { 
        
} 
    def _add_kid(key, x) : 
        if (x is None) : 
            kids [key] = None 
else : 
            if (type (x) in (type ([]), type (()))) : 
                x1 = [i for i in x if isinstance (i, TVTKBase)] 
                if x1 : 
                    kids [key] = x1 
else : 
                if isinstance (x, TVTKBase) : 
                    if hasattr (x, '__iter__') : 
                        if (len (list (x)) and isinstance (list (x) [0], TVTKBase)) : 
                            kids [key] = x 
else : 
                        kids [key] = x 
for method in methods : 
        attr = camel2enthought (method [0]) 
        if hasattr (obj, attr) : 
            _add_kid (attr, getattr (obj, attr)) 
if hasattr (obj, 'number_of_sources') : 
        srcs = [obj.get_source (i) for i in range (obj.number_of_sources)] 
        _add_kid ('source', srcs) 
else : 
        if hasattr (obj, 'source') : 
            _add_kid ('source', obj.source) 
if hasattr (obj, 'get_input') : 
        inputs = [] 
        if hasattr (obj, 'number_of_input_ports') : 
            if obj.number_of_input_ports : 
                inputs = list () 
                for i in range (attr.number_of_input_ports) : 
                    try : 
                        inputs.append (obj.get_input (i)) 
except TypeError : 
                        pass 
if (not inputs) : 
                    inputs = [obj.get_input ()] 
else : 
            inputs = [obj.get_input (i) for i in range (obj.number_of_inputs)] 
_add_kid ('input', inputs) 
else : 
        if hasattr (obj, 'input') : 
            _add_kid ('input', obj.input) 
if hasattr (obj, 'producer_port') : 
        _add_kid ('producer_port', obj.producer_port) 
return kids 

    
    

    Fix the buggy line: for i in range (attr.number_of_input_ports) :
assistant
#Here is Python program to fix the buggy line: for i in range (attr.

for i in range (obj.number_of_input_ports) :