复制代码 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")