Run command pipes with subprocess.Popen

How to run the following command using subprocess.Popen?

mysqldump database_name table_name | bzip2 > filename

I know os.system() can do the job but I dont want to wait for the dump to finish in main program.

From stackoverflow

• You want the shell=True option to make it execute shell commands:

  import subprocess
  subprocess.Popen("sleep 4s && echo right thar, right thar",shell=True);
  print 'i like it when you put it'
  

  which yeilds:

   I like it when you put it
   [4 seconds later]
   right thar, right thar