os¶
os模块的一些常见的用法
1、功能¶
Miscellaneous operating system interfaces.
2、os.system()¶
调用系统命令
用法
os.system('command')1.1、调用系统命令¶
一个简单的例子，最后一行的0为返回值：
>>> os.system('ping www.baidu.com -c 10')
PING www.a.shifen.com (180.97.33.107): 56 data bytes
64 bytes from 180.97.33.107: icmp_seq=0 ttl=55 time=11.707 ms
64 bytes from 180.97.33.107: icmp_seq=1 ttl=55 time=8.147 ms
64 bytes from 180.97.33.107: icmp_seq=2 ttl=55 time=27.679 ms
64 bytes from 180.97.33.107: icmp_seq=3 ttl=55 time=9.168 ms
64 bytes from 180.97.33.107: icmp_seq=4 ttl=55 time=10.095 ms
64 bytes from 180.97.33.107: icmp_seq=5 ttl=55 time=15.279 ms
64 bytes from 180.97.33.107: icmp_seq=6 ttl=55 time=9.284 ms
64 bytes from 180.97.33.107: icmp_seq=7 ttl=55 time=8.868 ms
64 bytes from 180.97.33.107: icmp_seq=8 ttl=55 time=8.779 ms
64 bytes from 180.97.33.107: icmp_seq=9 ttl=55 time=8.844 ms
--- www.a.shifen.com ping statistics ---
10 packets transmitted, 10 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 8.147/11.785/27.679/5.659 ms
0
1.2、获取执行返回值¶
对命令赋值则得到返回值：
>>> s = os.system('ping www.baidu.com -c 1')
PING www.a.shifen.com (180.97.33.108): 56 data bytes
64 bytes from 180.97.33.108: icmp_seq=0 ttl=55 time=10.432 ms
--- www.a.shifen.com ping statistics ---
1 packets transmitted, 1 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 10.432/10.432/10.432/0.000 ms
>>> s
0
执行成功，则返回值为0
使用 sys.exit(xxx) 自定义返回值：
import sys
if __name__ == '__main__':
sys.exit(2)
1.3、python执行返回值和shell不同的情况¶
python执行返回值为512
>>> os.system('python3 /Users/huangyisan/Desktop/Python_project/Mage_edu/normal_func/exit_code.py')
512
shell中执行得到的返回值为2
huangyisan\:~ $ python3 /Users/huangyisan/Desktop/Python_project/Mage_edu/normal_func/exit_code.py
huangyisan\:~ $ echo $?
2
原因为，c的int占4个字节，所以”2”是”512”右移8位得到的，”512”是”2”左移8位得到的。
>>> 512>>8
2
>>> 2<<8
512
3、os.popen()¶
获取执行内容
>>> f = os.popen('ping baidu.com -c 1')
>>> f.read()
'PING baidu.com (220.181.57.216): 56 data bytes\n64 bytes from 220.181.57.216: icmp_seq=0 ttl=56 time=30.260 ms\n\n--- baidu.com ping statistics ---\n1 packets transmitted, 1 packets received, 0.0% packet loss\nround-trip min/avg/max/stddev = 30.260/30.260/30.260/0.000 ms\n'
>>> f.close()
- 先os.popen()实例化，然后对对象read()操作。
- 最后对对象进行close()关闭操作。
可以对内容进行遍历：
>>> f = os.popen('ping baidu.com -c 1')
>>> for i in f:
... print(i)
...
PING baidu.com (220.181.57.216): 56 data bytes
64 bytes from 220.181.57.216: icmp_seq=0 ttl=56 time=31.261 ms
--- baidu.com ping statistics ---
1 packets transmitted, 1 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 31.261/31.261/31.261/0.000 ms
>>> f.close()