pyedf.py

#!/usr/bin/env python
# encoding: utf-8
"""
pyedf.py

Created by Ray Slakinski on 2010-09-14.
Copyright (c) 2010 Ray Slakinski. All rights reserved.
"""
import sys
import argparse
import re


def read_edf_file(fileobj):
    data = fileobj.read()
    header = {}
    # Parse header information based on the EDF/EDF+ specs
    # http://www.edfplus.info/specs/index.html
    header['version'] = data[0:7].strip()
    header['patient_id'] = data[7:88].strip()
    header['rec_id'] = data[88:168].strip()
    header['startdate'] = data[168:176].strip()
    header['starttime'] = data[176:184].strip()
    header['header_bytes'] = int(data[184:192].strip())
    header['num_items'] = int(data[236:244].strip())
    header['data_duration'] = float(data[244:252].strip())
    header['num_signals'] = int(data[252:256].strip())
    # more data 256 chars down. in header, but ignoring for now
    records = []
    records_a = records.append
    rec_pos = 512
    rec_size = 36
    # skip first rec
    rec_pos += rec_size
    for i in range(header['num_items']-1):
        record = {}
        record_split = data[rec_pos:rec_pos+rec_size].split('\x14')
        matches = re.findall(r'([\d]+)', record_split[2])
        record['type'] = record_split[3].strip()
        record['time'] = {
            'start': int(matches[0]),
            'durration': int(matches[1]),
        }
        records_a(record)
        rec_pos += rec_size
    return {'header': header, 'records': records}


def main():
    # create the parser
    parser = argparse.ArgumentParser(description='Process a given EDF File.')
    parser.add_argument(
        '-f',
        '--file',
        type=argparse.FileType('r'),
        help='EDF File to be processed.',
    )
    args = parser.parse_args()
    data = read_edf_file(args.file)
    args.file.close()
    print data

if __name__ == '__main__':
    main()