def __init__(self, file_id_mod, settings):

        self.settings = settings

        try:
            self.header = Header(
                settings['immediate_dest'],
                settings['immediate_org'], file_id_mod,
                settings['immediate_dest_name'], settings['immediate_org_name']
            )
        except KeyError:
            raise Exception(
                'Settings require: "immediate_dest", "immediate_org", \
                immediate_dest_name", and "immediate_org_name"'
            )

        self.batches = list()
The file_id_mod should be 'A' for the first of the day, 'B'
dataset/ETHPy150Open travishathaway/python-ach/ach/builder.py/AchFile.__init__