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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 init_config(self):
 """Patch input.nml as a new or restart run."""


        input_fpath = os.path.join(self.work_path, 'input.nml')

        input_nml = f90nml.read(input_fpath)

        if self.expt.counter == 0 or self.expt.repeat_run:
            input_type = 'n'
        else:
            input_type = 'r'
        input_nml['MOM_input_nml']['input_filename'] = input_type

        f90nml.write(input_nml, input_fpath, force=True)