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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _print_code(self, code):
 """Prepare code for string writing."""

        # This needs a rewrite --- it doesn't check for match clashes! So sub11 would be replaced by sub1 before being replaced with sub11!!
        for key in self.variables.keys():
            for arg in self.variables[key]:
                code = code.replace(arg.name, 'self.'+arg.name)
        return code