python分割文件

#将一个文件分割成固定行的小文件

import os
import sys

num = 0
fnum = 0

path = sys.argv[1]
fname = 'data-%d' % fnum
fw = open(fname,'w')
for t in os.listdir(path):
    filename = os.path.join(path,t)
    fd = open(filename)
    for line in fd:
        line = line.strip()
        num = num + 1 
        if line:
            if num > 10000000:
                num = 0
                fw.close()
                fnum = fnum + 1 
                fname = 'data-%d' % fnum
                fw = open(fname,'w')
            fw.write(line + '\n')
fw.close()