human
Solve the following python programming problem given the following code:
def grabFieldData(self, response) : 
    '
        Pull the appropriate field data from the context to pass to the next wizard step
        ' 
    previous_fields = response.context ['previous_fields'] 
    fields = { 
        'wizard_step' : response.context ['step0'], 
} 
    def grab(m) : 
        fields [m.group (1)] = m.group (2) 
        return '' 
self.input_re.sub (grab, grab) 
    return fields 

    
    

    Fix the buggy line: self.input_re.sub (grab, grab)
assistant
#Here is Python code to fix the buggy line: self.

self.input_re.sub (grab, previous_fields)