Generic Text Dumper v1

import os
import struct
import sys

def get_data(filename):
    totalbytes = os.path.getsize(filename)
    infile = open(filename, 'rb')
    totalfiledata = infile.read(totalbytes)
    infile.close()
    return totalfiledata

def is_jis_char(s):
    try:
        s.decode('cp932')
    except UnicodeDecodeError:
        return False
    if len(s.decode('cp932')) == 1:
        return True
    return False

def myprogram(f):
    output = []
    filedata = get_data(f + '.unpack')
    pos = 0
    while pos < len(filedata) - 1:
        if is_jis_char(filedata[pos:pos+2]):
            flag = False
            startpos = pos
            while True:
                pos += 1
                if filedata[pos] == '\x00':
                    break
            endpos = pos
            while filedata[pos] == '\x00':
                if pos == len(filedata) - 1:
                    break
                pos += 1
            allowable_len = pos - startpos - 1

            if '\\n' in filedata[startpos:endpos]:
                flag = True
                s = filedata[startpos:filedata.find('\\n',startpos)]
                s1 = filedata[filedata.find('\\n',startpos) + 2:endpos]
            else:
                s = filedata[startpos:endpos]
            output.append('\t'.join([hex(startpos), s, str(allowable_len)]) + '\n')
            if flag:
                output.append('\t'.join(['', s1, '']) + '\n')
        else:
            pos += 1
    outfile = open(f + '.data','wb')
    outfile.write(''.join(output))
    outfile.close()

myprogram(sys.argv[1])