python: error when executing subprocess.popen

Question

when I execute the following function in centos, I get the error

def install_requests_lib():
   try:
      import requests
      return
   except ImportError, e:
      print "module does not exist, installing..."
      if(platform.system().lower()=='darwin'):
          print "install requests before proceeding, run **sudo pip install requests**"
          sys.exit(2)
      elif(platform.system().lower()=='linux'):
          print "installing"
          p=Popen(["yum","-y","install","python-requests"], stdout=PIPE, shell=True)
          p.communicate()
          print p.returncode

error:

module does not exist, installing...
installing
You need to give some command
1

I cannot figure out what is wrong.

I executed with stdin=PIPE argument, still I get the same error.

Answer 1

当您的意思是yum install -y时，您正在尝试执行yum -y install 。

Answer 2

The arguments in your arg list after "yum" aren't being executed if you give the argument shell=True . Remove the shell=True argument and it should work.

Alternatively, you could supply the full command line as a string and keep the shell=True argument:

p=Popen("yum install -y python-requests", stdout=PIPE, shell=True)

but it's generally discouraged to do so, for many reasons .