hex decoder/encoder by python

trunkfile.py

import sys,os,gzip

def is_gzip(filename):
    f = open(filename, 'rb')
    if f.read(2).encode('hex') == '1f8b':
        return True
        pass
    return False
    pass

def to_btye(filename,zip_mode):
    file_static = open(filename, 'rb')
    if zip_mode:
        file_zip = gzip.open('compressed_'+os.path.splitext(filename)[0],'wb')
    elif ~zip_mode:
        file_zip = open('compressed_'+os.path.splitext(filename)[0],'wb')
        pass
    
    while True:
        byte = file_static.read(1)
        if byte == '':
            break
        else:
            try:
                string = str(ord(byte))
                file_zip.write((('0'*(4-len(string)))+string).decode('hex'))
                pass
            except Exception, e:
                print e
            pass
        pass
    file_static.close()
    file_zip.close()
    is_gzip('compressed_'+os.path.splitext(filename)[0])
    pass

def to_file(filename,unzip_mode):
    if unzip_mode == 1:
        file_compressed = open(filename, 'rb')
    elif unzip_mode == 2:
        file_compressed = gzip.open(filename, 'rb')
    elif unzip_mode == 3:
        if is_gzip(filename):
            file_compressed = gzip.open(filename, 'rb')
        else:
            file_compressed = open(filename, 'rb')
            pass
        pass
    
    file_real = open('test_'+os.path.splitext(filename)[0],'wb')
    while True:
        byte = file_compressed.read(2)
        if byte == '':
            break
        else:
            try:
                file_real.write(chr(int(str(byte).encode('hex'))))
                pass
            except Exception, e:
                print e
            pass
        pass

    file_compressed.close()
    file_real.close()
    pass

if __name__ == '__main__':
    try:
        flag = sys.argv[1]
        if flag == '-f':
            to_file(sys.argv[2],1)
        elif flag == '-b':
            to_btye(sys.argv[2],False)
        elif flag == '-fz':
            to_file(sys.argv[2],2)
        elif flag == '-bz':
            to_btye(sys.argv[2],True)
        elif flag == '-fa':
            to_file(sys.argv[2],3)
        else:
            to_btye(sys.argv[1],False)
            pass
        pass
    except Exception, e:
        print e