sys模块

一、语法

1 sys.argv           命令行参数List，第一个元素是程序本身路径
2 sys.exit(n)        退出程序，正常退出时exit(0)
3 sys.version        获取Python解释程序的版本信息
4 sys.maxint         最大的Int值
5 sys.path           返回模块的搜索路径，初始化时使用PYTHONPATH环境变量的值
6 sys.platform       返回操作系统平台名称

二、文件拷贝

# src_file=sys.argv[1]
# dst_file=sys.argv[2]
# # 判断
#
# with open(r'%s' %src_file,mode='rb') as read_f,
#     open(r'%s' %dst_file,mode='wb') as write_f:
#     for line in read_f:
#         write_f.write(line)

三、打印进度条

import time


def progress(percent):
    if percent > 1:
        percent = 1
    res = int(50 * percent) * '#'
    print('
[%-50s] %d%%' % (res, int(100 * percent)), end='')

recv_size=0
total_size=1025011

while recv_size < total_size:
    time.sleep(0.01) # 下载了1024个字节的数据

    recv_size+=1024 # recv_size=2048

    # 打印进度条
    # print(recv_size)
    percent = recv_size / total_size  # 1024 / 333333
    progress(percent)