human
Solve the following python programming problem given the following code:
def _print_ctor(self) : 
    fields = ([field for field in self._fields if (not field [2])] + [field for field in fields._fields if field [2]]) 
    ctor_args = ', '.join (((snake (name) + ('=None' if nullable else '')) for (type, name, nullable, plural) in fields)) 
    print ('
    def __init__(self, {ctor_args}, loc=None):
        self.loc = loc'.format (ctor_args = ctor_args)) 
    for (type, name, nullable, plural) in self._fields : 
        print ('        self.{name} = {name}'.format (name = snake (name))) 

    
    

    Fix the buggy line: fields = ([field for field in self._fields if (not field [2])] + [field for field in fields._fields if field [2]])
assistant
#Here is Python program to fix the buggy line: fields = ([field for field in self.

fields = ([field for field in self._fields if (not field [2])] + [field for field in self._fields if field [2]])