Python语言学习之三：sys.argv[]

sys.argv[]是用来获取命令行参数的，sys.argv[0]表示代码本身文件路径，所以参数从1开始.

#!/usr/bin/env python#_*_ coding:utf-8 _*_import sysdef readfile(filename):  #定义readfile函数，从文件中读出文件内容    '''''''''Print a file to the standard output.'''    f = file(filename)    while True:        line = f.readline()        if len(line) == 0:            break        print(line), # notice comma  分别输出每行内容    f.close()# Script starts from hereprint(sys.argv)if len(sys.argv) < 2:    print('No action specified.')    sys.exit()if sys.argv[1].startswith('--'):    option = sys.argv[1][2:]    # fetch sys.argv[1] but without the first two characters    if option == 'version':  #当命令行参数为-- version，显示版本号        print('Version 1.2')    elif option == 'help':  #当命令行参数为--help时，显示相关帮助内容        print ('''This program prints files to the standard output.            Any number of files can be specified.            Options include:        --version : Prints the version number                                       --help    : Display this help''')    else:        print('Unknown option.')    sys.exit()else:    for filename in sys.argv[1:]: #当参数为文件名时，传入readfile，读出其内容        readfile(filename)