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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 read_creds_from_csv(filename):
 """ Read credentials from a CSV file :param filename: :return: """

    key_id = None
    secret = None
    mfa_serial = None
    secret_next = False
    with open(filename, 'rt') as csvfile:
        for i, line in enumerate(csvfile):
            values = line.split(',')
            for v in values:
                if v.startswith('AKIA'):
                    key_id = v.strip()
                    secret_next = True
                elif secret_next:
                    secret = v.strip()
                    secret_next = False
                elif re_mfa_serial_format.match(v):
                    mfa_serial = v.strip()
    return key_id, secret, mfa_serial