代码如下:
import time
def block(file,size=65536):
    while true:
        nb = file.read(size)
        if not nb:
           break
        yield nb
def getlinecount(filename):
    with open(filename,r,encoding=utf-8) as f:
        return sum(line.count(\n) for line in block(f))
if __name__ == __main__:
    import sys
    import os
    if len(sys.argv) != 2:
        print(error imput argument)
        sys.exit(-1)
    if not os.path.isfile(sys.argv[1]) :
       print(sys.argv + is not a file)
       sys.exit(-1)
    start_time = time.time()
    print(getlinecount(sys.argv[1]))
    print(time.time() - start_time ,seconds)