Python调用系统命令的四种方法

import os
statusCode=os.system("powershell sleep 3 ;echo 天下大势为我所控")
print("over",statusCode)

import os
pipe=os.popen("powershell sleep 3 ;echo 天下大势为我所控")
s=pipe.read()
print(s)

import commands
(status, output) = commands.getstatusoutput('cat /proc/cpuinfo')
print status,output

import subprocess
statusCode=subprocess.call("echo one",shell=True)#相当于system命令，只返回状态值，并打印输出到stdout
print(statusCode)
x=subprocess.check_call(["echo","  two"],shell=True)
print(x)
x=subprocess.check_output("echo three",shell=True)#只获取output
print(x)

import subprocess

obj = subprocess.Popen("mkdir t3", shell=True, cwd='/home/dev',)     #在cwd目录下执行命令
import subprocess

obj = subprocess.Popen(["python"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
obj.stdin.write("print(1)\n")
obj.stdin.write("print(2)")
obj.stdin.close()

cmd_out = obj.stdout.read()
obj.stdout.close()
cmd_error = obj.stderr.read()
obj.stderr.close()

print(cmd_out)
print(cmd_error)
import subprocess

obj = subprocess.Popen(["python"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
obj.stdin.write("print(1)\n")
obj.stdin.write("print(2)")

out_error_list = obj.communicate()
print(out_error_list)
import subprocess

obj = subprocess.Popen(["python"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
out_error_list = obj.communicate('print("hello")')
print(out_error_list)