convert zemax pupil data to csv

zmx2csv.py

#!/usr/bin/env python
"""
zmx2csv.py: convert zemax output to csv for matlab import

usage: zmx2csv.py filename.txt ... 

reads each filename.txt, outputting filename.csv
sample input file: forPupilMapping_Prescription.txt
"""
import sys
import argparse
import csv

def parse_line(line):
    name, value = line.split(':')
    name = name.strip()
    value = value.split("=")[-1].split(",")[-1].split("(")[0].strip()
    # pull a number out of the value string if we can
    try:
        value = int(value)
    except ValueError:
        try:
            value = float(value)
        except ValueError:
            pass
    return name, value

def main(args=None, skip=10, keep=50):
    parser = argparse.ArgumentParser(
        description='Infer log message patterns from logfiles'
    )
    parser.add_argument(
        "infile", nargs='*',  
        help="path(s) to input files.")
    parser.add_argument(
        "--skip", type=int, default=skip,
        help="skip this many lines at the beginning (default = %d)" % skip)
    parser.add_argument(
        "--keep", type=int, default=keep,
        help="keep this many lines after skipping (default = %d)" % keep)
    parser.add_argument(
        "--all", action='store_true',
        help="keep lines without numeric data")
    parser.add_argument(
        "--noheader", action='store_true',
        help="don't write header in csv file")
    args = parser.parse_args(args=args)
    for fname in args.infile:
        data = {}
        with open(fname,"r") as f:
            for i, line in enumerate(f):
                line = line.replace('\0', '').replace('\r','') # remove DOS bullshit
                if (i < args.skip):
                    continue
                elif (i == args.skip + args.keep):
                    break
                name, value = parse_line(line)
                if (args.all or isinstance(value, (int, float))):
                    data[name] = value
            # data now contains an entry for each keeper line        
            fname_csv = fname.split('.')[0]+'.csv'
            with open(fname_csv, 'w') as csvfile:
                writer = csv.DictWriter(csvfile, data.keys())
                if (not args.noheader):
                    writer.writeheader()
                writer.writerow(data)
                
if __name__ == '__main__':
    main()