title: Write using Configparser or propparser changes case of properties
body: <p>i am using configparser or propparser to read a property from a file and adding it if it is not present</p>
  
  <p>But adding the property using configparser or propparser, is changing the case of remaining properties</p>
  
  <p>Following is my script</p>
  
  <pre><code>from ConfigParser import  RawConfigParser
  
  def modifyInstallProperties ():
     propParser = RawConfigParser()
     propParser.read('/home/ram/test.properties')
  
     try:
       ip = propParser.get('Client', 'export_sftp_identity_file')
       print "ip is " +ip
     except :
       propParser.set('Client','#export_sftp_identity_file','/home/ram/.ssh/id_rsa')
       with open('/home/ram/test.properties', 'w') as configfile:
          propParser.write(configfile)
  
  modifyInstallProperties()
  </code></pre>
  
  <p>i am writing property "export_sftp_identity_file", if it is no there, but it changes the case of remaining properties</p>
  
  <pre><code>before                                                 after
  base_server_IP = 172.31.1.52                         base_server_ip = 172.31.1.52 (ip instead of IP)
  installShard = false                                 installshard = false ( s instead of S in shard)
  installDbServer = false                              installdbserver = false (d instead of D in Dbserver)
  ....
  </code></pre>
  
  <p>test.properties, before running the script</p>
  
  <pre><code>[Client]
  enable_https_from_patch = false
  client_install_dir = /centina/client
  export_sftp_target_port = 22
  client_jboss_dir = /centina/client/jboss-eap-5.2.0
  base_server_IP = 172.31.1.52
  export_sftp_target_host = 172.31.1.52
  enable_https = false
  export_sftp_target_password = centina
  enable_http = true
  export_sftp_target_user = centina
  
  [Common]
  db_pm_port = 3306
  installShard = false
  db_sla_port = 3306
  jdk_dir = /opt/jdk
  installDbServer = false
  installDbMultiple = false
  installOnlyDbServer = false
  installClientServer = false
  installLoader = false
  installMedMultiple = false
  db_sa_port = 3306
  db_server_IP = 172.31.1.52
  installDbSlave = false
  installOnlyMedServer = false
  server_bind_ip = 0.0.0.0
  installMedServer = false
  db_fm_port = 3306
  standAloneInstallation = false
  installAppServer = false
  db_spm_port = 3306
  </code></pre>
  
  <p>after running the script</p>
  
  <pre><code>[Client]
  enable_https_from_patch = false
  client_install_dir = /centina/client
  export_sftp_target_port = 22
  client_jboss_dir = /centina/client/jboss-eap-5.2.0
  base_server_ip = 172.31.1.52
  export_sftp_target_host = 172.31.1.52
  enable_https = false
  export_sftp_target_password = centina
  enable_http = true
  export_sftp_target_user = centina
  #export_sftp_identity_file = /home/centina/.ssh/id_rsa
  
  [Common]
  db_pm_port = 3306
  installshard = false
  db_sla_port = 3306
  jdk_dir = /opt/jdk
  installdbserver = false
  installdbmultiple = false
  installonlydbserver = false
  installclientserver = false
  installloader = false
  installmedmultiple = false
  db_sa_port = 3306
  db_server_ip = 172.31.1.52
  installdbslave = false
  installonlymedserver = false
  server_bind_ip = 0.0.0.0
  installmedserver = false
  db_fm_port = 3306
  standaloneinstallation = false
  installappserver = false
  db_spm_port = 3306
  
  How to solve this
  </code></pre>