title: How to do sed like text replace with python?
body: <p>I would like to enable all apt repositories in this file</p>
  
  <pre><code>cat /etc/apt/sources.list
  ## Note, this file is written by cloud-init on first boot of an instance                                                                                                            
  ## modifications made here will not survive a re-bundle.                                                                                                                            
  ## if you wish to make changes you can:                                                                                                                                             
  ## a.) add 'apt_preserve_sources_list: true' to /etc/cloud/cloud.cfg                                                                                                                
  ##     or do the same in user-data
  ## b.) add sources in /etc/apt/sources.list.d                                                                                                                                       
  #                                                                                                                                                                                   
  
  # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to                                                                                                           
  # newer versions of the distribution.                                                                                                                                               
  deb http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ maverick main                                                                                                                   
  deb-src http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ maverick main                                                                                                               
  
  ## Major bug fix updates produced after the final release of the                                                                                                                    
  ## distribution.                                                                                                                                                                    
  deb http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ maverick-updates main                                                                                                           
  deb-src http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ maverick-updates main                                                                                                       
  
  ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu                                                                                                         
  ## team. Also, please note that software in universe WILL NOT receive any                                                                                                           
  ## review or updates from the Ubuntu security team.                                                                                                                                 
  deb http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ maverick universe                                                                                                               
  deb-src http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ maverick universe                                                                                                           
  deb http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ maverick-updates universe
  deb-src http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ maverick-updates universe
  
  ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 
  ## team, and may not be under a free licence. Please satisfy yourself as to
  ## your rights to use the software. Also, please note that software in 
  ## multiverse WILL NOT receive any review or updates from the Ubuntu
  ## security team.
  # deb http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ maverick multiverse
  # deb-src http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ maverick multiverse
  # deb http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ maverick-updates multiverse
  # deb-src http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ maverick-updates multiverse
  
  ## Uncomment the following two lines to add software from the 'backports'
  ## repository.
  ## N.B. software from this repository may not have been tested as
  ## extensively as that contained in the main release, although it includes
  ## newer versions of some applications which may provide useful features.
  ## Also, please note that software in backports WILL NOT receive any review
  ## or updates from the Ubuntu security team.
  # deb http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ maverick-backports main restricted universe multiverse
  # deb-src http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ maverick-backports main restricted universe multiverse
  
  ## Uncomment the following two lines to add software from Canonical's
  ## 'partner' repository.
  ## This software is not part of Ubuntu, but is offered by Canonical and the
  ## respective vendors as a service to Ubuntu users.
  # deb http://archive.canonical.com/ubuntu maverick partner
  # deb-src http://archive.canonical.com/ubuntu maverick partner
  
  deb http://security.ubuntu.com/ubuntu maverick-security main
  deb-src http://security.ubuntu.com/ubuntu maverick-security main
  deb http://security.ubuntu.com/ubuntu maverick-security universe
  deb-src http://security.ubuntu.com/ubuntu maverick-security universe
  # deb http://security.ubuntu.com/ubuntu maverick-security multiverse
  # deb-src http://security.ubuntu.com/ubuntu maverick-security multiverse
  </code></pre>
  
  <p>With sed this is a simple <code>sed -i 's/^# deb/deb/' /etc/apt/sources.list</code> what's the most elegant ("pythonic") way to do this?</p>