fix pylint warnings (LP: #914739) [Juerg Haefliger]

LP: #914739

44 files changed, 249 insertions, 257 deletions

diff --git a/ChangeLog b/ChangeLog
index a278a514..a1ae3b7e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -18,6 +18,7 @@
  - part-handlers now get base64 decoded content rather than 2xbase64 encoded
    in the payload parameter. (LP: #874342)
  - add test case framework [Mike Milner] (LP: #890851)
+ - fix pylint warnings [Juerg Haefliger] (LP: #914739)
 0.6.2:
  - fix bug where update was not done unless update was explicitly set.
    It would not be run if 'upgrade' or packages were set to be installed
diff --git a/cloud-init-cfg.py b/cloud-init-cfg.py
index 2930cd88..de64ef9c 100755
--- a/cloud-init-cfg.py
+++ b/cloud-init-cfg.py
@@ -23,7 +23,6 @@ import cloudinit.util as util
 import cloudinit.CloudConfig as CC
 import logging
 import os
-import traceback
 
 def Usage(out = sys.stdout):
     out.write("Usage: %s name\n" % sys.argv[0])
diff --git a/cloud-init-query.py b/cloud-init-query.py
index 3e8c24ab..cfe9b429 100755
--- a/cloud-init-query.py
+++ b/cloud-init-query.py
@@ -20,9 +20,6 @@
 import sys
 import cloudinit
 import cloudinit.CloudConfig
-import logging
-import os
-import traceback
 
 def Usage(out = sys.stdout):
     out.write("Usage: %s name\n" % sys.argv[0])
@@ -34,7 +31,6 @@ def main():
         sys.exit(1)
 
     cc = cloudinit.CloudConfig.CloudConfig(cloudinit.cloud_config)
-    cloud_config = cc.cfg
     data = {
         'user_data' : cc.cloud.get_userdata(),
         'user_data_raw' : cc.cloud.get_userdata_raw(),
diff --git a/cloud-init.py b/cloud-init.py
index bc673265..8279a0b0 100755
--- a/cloud-init.py
+++ b/cloud-init.py
@@ -56,12 +56,12 @@ def main():
 
     now = time.strftime("%a, %d %b %Y %H:%M:%S %z",time.gmtime())
     try:
-       uptimef=open("/proc/uptime")
-       uptime=uptimef.read().split(" ")[0]
-       uptimef.close()
+        uptimef=open("/proc/uptime")
+        uptime=uptimef.read().split(" ")[0]
+        uptimef.close()
     except IOError as e:
-       warn("unable to open /proc/uptime\n")
-       uptime = "na"
+        warn("unable to open /proc/uptime\n")
+        uptime = "na"
 
     try:
         cfg = cloudinit.get_base_cfg(cfg_path)
diff --git a/cloudinit/CloudConfig/__init__.py b/cloudinit/CloudConfig/__init__.py
index 82f422fc..f5c4143c 100644
--- a/cloudinit/CloudConfig/__init__.py
+++ b/cloudinit/CloudConfig/__init__.py
@@ -33,7 +33,7 @@ class CloudConfig():
     cfgfile = None
     cfg = None
 
-    def __init__(self,cfgfile, cloud=None, ds_deps=[]):
+    def __init__(self,cfgfile, cloud=None, ds_deps=None):
         if cloud == None:
             self.cloud = cloudinit.CloudInit(ds_deps)
             self.cloud.get_data_source()
@@ -233,7 +233,9 @@ def run_per_instance(name, func, args, clear_on_fail=False):
         raise
 
 # apt_get top level command (install, update...), and args to pass it
-def apt_get(tlc,args=[]):
+def apt_get(tlc,args=None):
+    if args is None:
+        args = []
     e=os.environ.copy()
     e['DEBIAN_FRONTEND']='noninteractive'
     cmd=[ 'apt-get',
diff --git a/cloudinit/CloudConfig/cc_apt_update_upgrade.py b/cloudinit/CloudConfig/cc_apt_update_upgrade.py
index 0677ceb5..0cbe02d4 100644
--- a/cloudinit/CloudConfig/cc_apt_update_upgrade.py
+++ b/cloudinit/CloudConfig/cc_apt_update_upgrade.py
@@ -22,7 +22,7 @@ import os
 import glob
 import cloudinit.CloudConfig as cc
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,cloud,log,_args):
     update = util.get_cfg_option_bool(cfg, 'apt_update', False)
     upgrade = util.get_cfg_option_bool(cfg, 'apt_upgrade', False)
 
@@ -102,14 +102,14 @@ def handle(name,cfg,cloud,log,args):
     return(True)
 
 def mirror2lists_fileprefix(mirror):
-    file=mirror
+    string=mirror
     # take of http:// or ftp://
-    if file.endswith("/"): file=file[0:-1]
-    pos=file.find("://")
+    if string.endswith("/"): string=string[0:-1]
+    pos=string.find("://")
     if pos >= 0:
-        file=file[pos+3:]
-    file=file.replace("/","_")
-    return file
+        string=string[pos+3:]
+    string=string.replace("/","_")
+    return string
 
 def rename_apt_lists(omirror,new_mirror,lists_d="/var/lib/apt/lists"):
     
@@ -117,11 +117,11 @@ def rename_apt_lists(omirror,new_mirror,lists_d="/var/lib/apt/lists"):
     nprefix="%s/%s" % (lists_d,mirror2lists_fileprefix(new_mirror))
     if(oprefix==nprefix): return
     olen=len(oprefix)
-    for file in glob.glob("%s_*" % oprefix):
-        os.rename(file,"%s%s" % (nprefix, file[olen:]))
+    for filename in glob.glob("%s_*" % oprefix):
+        os.rename(filename,"%s%s" % (nprefix, filename[olen:]))
 
 def get_release():
-    stdout, stderr = subprocess.Popen(['lsb_release', '-cs'], stdout=subprocess.PIPE).communicate()
+    stdout, _stderr = subprocess.Popen(['lsb_release', '-cs'], stdout=subprocess.PIPE).communicate()
     return(stdout.strip())
 
 def generate_sources_list(codename, mirror):
@@ -131,7 +131,9 @@ def generate_sources_list(codename, mirror):
 # srclist is a list of dictionaries, 
 # each entry must have: 'source'
 # may have: key, ( keyid and keyserver)
-def add_sources(srclist, searchList={ }):
+def add_sources(srclist, searchList=None):
+    if searchList is None:
+        searchList = {}
     elst = []
 
     for ent in srclist:
@@ -202,7 +204,7 @@ def find_apt_mirror(cloud, cfg):
 
         if not mirror and cloud:
             # if we have a fqdn, then search its domain portion first
-            ( hostname, fqdn ) = util.get_hostname_fqdn(cfg, cloud)
+            ( _hostname, fqdn ) = util.get_hostname_fqdn(cfg, cloud)
             mydom = ".".join(fqdn.split(".")[1:])
             if mydom:
                 doms.append(".%s" % mydom)
diff --git a/cloudinit/CloudConfig/cc_bootcmd.py b/cloudinit/CloudConfig/cc_bootcmd.py
index 5a9e4356..fc925447 100644
--- a/cloudinit/CloudConfig/cc_bootcmd.py
+++ b/cloudinit/CloudConfig/cc_bootcmd.py
@@ -21,7 +21,7 @@ import tempfile
 from cloudinit.CloudConfig import per_always
 frequency = per_always
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,cloud,log,_args):
     if not cfg.has_key("bootcmd"):
         return
 
diff --git a/cloudinit/CloudConfig/cc_byobu.py b/cloudinit/CloudConfig/cc_byobu.py
index 406a1f67..dd510dda 100644
--- a/cloudinit/CloudConfig/cc_byobu.py
+++ b/cloudinit/CloudConfig/cc_byobu.py
@@ -19,7 +19,7 @@ import cloudinit.util as util
 import subprocess
 import traceback
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,_cloud,log,args):
     if len(args) != 0:
         value = args[0]
     else:
diff --git a/cloudinit/CloudConfig/cc_chef.py b/cloudinit/CloudConfig/cc_chef.py
index 14960a3c..977fe80f 100644
--- a/cloudinit/CloudConfig/cc_chef.py
+++ b/cloudinit/CloudConfig/cc_chef.py
@@ -14,19 +14,16 @@
 #
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import os
-import pwd
-import socket
 import subprocess
 import json
-import StringIO
-import ConfigParser
 import cloudinit.CloudConfig as cc
 import cloudinit.util as util
 
 ruby_version_default = "1.8"
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,cloud,log,_args):
     # If there isn't a chef key in the configuration don't do anything
     if not cfg.has_key('chef'): return
     chef_cfg = cfg['chef']
@@ -44,7 +41,6 @@ def handle(name,cfg,cloud,log,args):
         with open('/etc/chef/validation.pem', 'w') as validation_key_fh:
             validation_key_fh.write(validation_key)
 
-    validation_name = chef_cfg.get('validation_name','chef-validator')
     # create the chef config from template
     util.render_to_file('chef_client.rb', '/etc/chef/client.rb',
             {'server_url': chef_cfg['server_url'], 
@@ -90,9 +86,9 @@ def get_ruby_packages(version):
 def install_chef_from_gems(ruby_version, chef_version = None):
     cc.install_packages(get_ruby_packages(ruby_version))
     if not os.path.exists('/usr/bin/gem'):
-      os.symlink('/usr/bin/gem%s' % ruby_version, '/usr/bin/gem')
+        os.symlink('/usr/bin/gem%s' % ruby_version, '/usr/bin/gem')
     if not os.path.exists('/usr/bin/ruby'):
-      os.symlink('/usr/bin/ruby%s' % ruby_version, '/usr/bin/ruby')
+        os.symlink('/usr/bin/ruby%s' % ruby_version, '/usr/bin/ruby')
     if chef_version:
         subprocess.check_call(['/usr/bin/gem','install','chef',
                                '-v %s' % chef_version, '--no-ri',
diff --git a/cloudinit/CloudConfig/cc_disable_ec2_metadata.py b/cloudinit/CloudConfig/cc_disable_ec2_metadata.py
index 5cd1d1c1..f06d4dfc 100644
--- a/cloudinit/CloudConfig/cc_disable_ec2_metadata.py
+++ b/cloudinit/CloudConfig/cc_disable_ec2_metadata.py
@@ -21,7 +21,7 @@ from cloudinit.CloudConfig import per_always
 
 frequency = per_always
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,_cloud,_log,_args):
     if util.get_cfg_option_bool(cfg, "disable_ec2_metadata", False):
         fwall="route add -host 169.254.169.254 reject"
         subprocess.call(fwall.split(' '))
diff --git a/cloudinit/CloudConfig/cc_final_message.py b/cloudinit/CloudConfig/cc_final_message.py
index fbdb5c94..c8631d01 100644
--- a/cloudinit/CloudConfig/cc_final_message.py
+++ b/cloudinit/CloudConfig/cc_final_message.py
@@ -24,7 +24,7 @@ frequency = per_always
 
 final_message = "cloud-init boot finished at $TIMESTAMP. Up $UPTIME seconds"
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,_cloud,log,args):
     if len(args) != 0:
         msg_in = args[0]
     else:
diff --git a/cloudinit/CloudConfig/cc_foo.py b/cloudinit/CloudConfig/cc_foo.py
index aa95578f..48d20e5b 100644
--- a/cloudinit/CloudConfig/cc_foo.py
+++ b/cloudinit/CloudConfig/cc_foo.py
@@ -15,10 +15,12 @@
 #
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
-import cloudinit
-import cloudinit.util as util
+
+#import cloudinit
+#import cloudinit.util as util
 from cloudinit.CloudConfig import per_instance
 
 frequency = per_instance
-def handle(name,cfg,cloud,log,args):
-   print "hi"
+
+def handle(_name,_cfg,_cloud,_log,_args):
+    print "hi"
diff --git a/cloudinit/CloudConfig/cc_grub_dpkg.py b/cloudinit/CloudConfig/cc_grub_dpkg.py
index b26e90e8..97d79bdb 100644
--- a/cloudinit/CloudConfig/cc_grub_dpkg.py
+++ b/cloudinit/CloudConfig/cc_grub_dpkg.py
@@ -15,12 +15,12 @@
 #
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import cloudinit.util as util
-import subprocess
 import traceback
 import os
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,_cloud,log,_args):
     
     idevs=None
     idevs_empty=None
diff --git a/cloudinit/CloudConfig/cc_keys_to_console.py b/cloudinit/CloudConfig/cc_keys_to_console.py
index 79dd2ea9..08e8f085 100644
--- a/cloudinit/CloudConfig/cc_keys_to_console.py
+++ b/cloudinit/CloudConfig/cc_keys_to_console.py
@@ -21,7 +21,7 @@ import subprocess
 
 frequency = per_instance
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,_cloud,log,_args):
     cmd = [ '/usr/lib/cloud-init/write-ssh-key-fingerprints' ]
     fp_blacklist = util.get_cfg_option_list_or_str(cfg, "ssh_fp_console_blacklist", [])
     key_blacklist = util.get_cfg_option_list_or_str(cfg, "ssh_key_console_blacklist", ["ssh-dss"])
diff --git a/cloudinit/CloudConfig/cc_landscape.py b/cloudinit/CloudConfig/cc_landscape.py
index e3e4f7ba..22a90665 100644
--- a/cloudinit/CloudConfig/cc_landscape.py
+++ b/cloudinit/CloudConfig/cc_landscape.py
@@ -32,7 +32,7 @@ lsc_builtincfg = {
   }
 }
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,_cloud,log,_args):
     """
     Basically turn a top level 'landscape' entry with a 'client' dict
     and render it to ConfigObj format under '[client]' section in
diff --git a/cloudinit/CloudConfig/cc_locale.py b/cloudinit/CloudConfig/cc_locale.py
index 8542f641..8e91d3bf 100644
--- a/cloudinit/CloudConfig/cc_locale.py
+++ b/cloudinit/CloudConfig/cc_locale.py
@@ -28,7 +28,7 @@ def apply_locale(locale, cfgfile):
 
     util.render_to_file('default-locale', cfgfile, { 'locale' : locale })
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,cloud,log,args):
     if len(args) != 0:
         locale = args[0]
     else:
diff --git a/cloudinit/CloudConfig/cc_mcollective.py b/cloudinit/CloudConfig/cc_mcollective.py
index c7912aa4..38fe4a3c 100644
--- a/cloudinit/CloudConfig/cc_mcollective.py
+++ b/cloudinit/CloudConfig/cc_mcollective.py
@@ -16,11 +16,9 @@
 #
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import os
-import pwd
-import socket
 import subprocess
-import fileinput
 import StringIO
 import ConfigParser
 import cloudinit.CloudConfig as cc
@@ -40,7 +38,7 @@ class FakeSecHead(object):
             finally: self.sechead = None
         else: return self.fp.readline()
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,_cloud,_log,_args):
     # If there isn't a mcollective key in the configuration don't do anything
     if not cfg.has_key('mcollective'): return
     mcollective_cfg = cfg['mcollective']
diff --git a/cloudinit/CloudConfig/cc_mounts.py b/cloudinit/CloudConfig/cc_mounts.py
index db382f04..a3036d5a 100644
--- a/cloudinit/CloudConfig/cc_mounts.py
+++ b/cloudinit/CloudConfig/cc_mounts.py
@@ -31,7 +31,7 @@ def is_mdname(name):
             return True
     return False
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,cloud,log,_args):
     # fs_spec, fs_file, fs_vfstype, fs_mntops, fs-freq, fs_passno
     defvals = [ None, None, "auto", "defaults,nobootwait", "0", "2" ]
     defvals = cfg.get("mount_default_fields", defvals)
@@ -116,7 +116,7 @@ def handle(name,cfg,cloud,log,args):
 
     # now, each entry in the cfgmnt list has all fstab values
     # if the second field is None (not the string, the value) we skip it
-    actlist = filter(lambda x: x[1] is not None, cfgmnt)
+    actlist = [x for x in cfgmnt if x[1] is not None]
 
     if len(actlist) == 0: return
 
diff --git a/cloudinit/CloudConfig/cc_phone_home.py b/cloudinit/CloudConfig/cc_phone_home.py
index f291e1d4..7897d31b 100644
--- a/cloudinit/CloudConfig/cc_phone_home.py
+++ b/cloudinit/CloudConfig/cc_phone_home.py
@@ -31,7 +31,7 @@ post_list_all = [ 'pub_key_dsa', 'pub_key_rsa', 'pub_key_ecdsa', 'instance_id',
 #  url: http://my.foo.bar/$INSTANCE_ID/
 #  post: [ pub_key_dsa, pub_key_rsa, pub_key_ecdsa, instance_id
 #   
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,cloud,log,args):
     if len(args) != 0:
         ph_cfg = util.readconf(args[0])
     else:
@@ -68,7 +68,6 @@ def handle(name,cfg,cloud,log,args):
         try:
             fp = open(path, "rb")
             all_keys[n] = fp.read()
-            all_keys[n]
             fp.close()
         except:
             log.warn("%s: failed to open in phone_home" % path)
diff --git a/cloudinit/CloudConfig/cc_puppet.py b/cloudinit/CloudConfig/cc_puppet.py
index c635d1f5..3748559a 100644
--- a/cloudinit/CloudConfig/cc_puppet.py
+++ b/cloudinit/CloudConfig/cc_puppet.py
@@ -25,7 +25,7 @@ import ConfigParser
 import cloudinit.CloudConfig as cc
 import cloudinit.util as util
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,cloud,log,_args):
     # If there isn't a puppet key in the configuration don't do anything
     if not cfg.has_key('puppet'): return
     puppet_cfg = cfg['puppet']
diff --git a/cloudinit/CloudConfig/cc_resizefs.py b/cloudinit/CloudConfig/cc_resizefs.py
index 6615636f..adec70be 100644
--- a/cloudinit/CloudConfig/cc_resizefs.py
+++ b/cloudinit/CloudConfig/cc_resizefs.py
@@ -15,9 +15,9 @@
 #
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import cloudinit.util as util
 import subprocess
-import traceback
 import os
 import stat
 import tempfile
@@ -25,7 +25,7 @@ from cloudinit.CloudConfig import per_always
 
 frequency = per_always
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,_cloud,log,args):
     if len(args) != 0:
         resize_root = False
         if str(args[0]).lower() in [ 'true', '1', 'on', 'yes']:
@@ -41,9 +41,9 @@ def handle(name,cfg,cloud,log,args):
     os.close(fd)
     
     try:
-       st_dev=os.stat("/").st_dev
-       dev=os.makedev(os.major(st_dev),os.minor(st_dev))
-       os.mknod(devpth, 0400 | stat.S_IFBLK, dev)
+        st_dev=os.stat("/").st_dev
+        dev=os.makedev(os.major(st_dev),os.minor(st_dev))
+        os.mknod(devpth, 0400 | stat.S_IFBLK, dev)
     except:
         if util.islxc():
             log.debug("inside lxc, ignoring mknod failure in resizefs")
@@ -53,7 +53,7 @@ def handle(name,cfg,cloud,log,args):
 
     cmd = [ 'blkid', '-c', '/dev/null', '-sTYPE', '-ovalue', devpth ]
     try:
-        (fstype,err) = util.subp(cmd)
+        (fstype,_err) = util.subp(cmd)
     except subprocess.CalledProcessError as e:
         log.warn("Failed to get filesystem type of maj=%s, min=%s via: %s" %
             (os.major(st_dev), os.minor(st_dev), cmd))
@@ -74,7 +74,7 @@ def handle(name,cfg,cloud,log,args):
         return
 
     try:
-        (out,err) = util.subp(resize_cmd)
+        util.subp(resize_cmd)
     except subprocess.CalledProcessError as e:
         log.warn("Failed to resize filesystem (%s)" % resize_cmd)
         log.warn("output=%s\nerror=%s\n", e.output[0], e.output[1])
diff --git a/cloudinit/CloudConfig/cc_rightscale_userdata.py b/cloudinit/CloudConfig/cc_rightscale_userdata.py
index 4875acbe..2b43023c 100644
--- a/cloudinit/CloudConfig/cc_rightscale_userdata.py
+++ b/cloudinit/CloudConfig/cc_rightscale_userdata.py
@@ -32,8 +32,9 @@
 ##   Therefore, this must run before that.
 ##
 ##
+
 import cloudinit.util as util
-from cloudinit.CloudConfig import per_once, per_always, per_instance
+from cloudinit.CloudConfig import per_instance
 from cloudinit import get_ipath_cur
 from urlparse import parse_qs
 
@@ -41,7 +42,7 @@ frequency = per_instance
 my_name = "cc_rightscale_userdata"
 my_hookname = 'CLOUD_INIT_REMOTE_HOOK'
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,_cfg,cloud,log,_args):
     try:
         ud = cloud.get_userdata_raw()
     except:
@@ -49,7 +50,7 @@ def handle(name,cfg,cloud,log,args):
         return
 
     try:
-        mdict = parse_qs(cloud.get_userdata_raw())
+        mdict = parse_qs(ud)
         if not my_hookname in mdict: return
     except:
         log.warn("failed to urlparse.parse_qa(userdata_raw())")
@@ -57,7 +58,6 @@ def handle(name,cfg,cloud,log,args):
 
     scripts_d = get_ipath_cur('scripts')
     i = 0
-    errors = [ ]
     first_e = None
     for url in mdict[my_hookname]:
         fname = "%s/rightscale-%02i" % (scripts_d,i)
diff --git a/cloudinit/CloudConfig/cc_rsyslog.py b/cloudinit/CloudConfig/cc_rsyslog.py
index a8ee8476..ab85a6d8 100644
--- a/cloudinit/CloudConfig/cc_rsyslog.py
+++ b/cloudinit/CloudConfig/cc_rsyslog.py
@@ -15,16 +15,16 @@
 #
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import cloudinit
 import logging
 import cloudinit.util as util
-import subprocess
 import traceback
 
 DEF_FILENAME = "20-cloud-config.conf"
 DEF_DIR = "/etc/rsyslog.d"
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,_cloud,log,_args):
     # rsyslog:
     #  - "*.* @@192.158.1.1"
     #  - content: "*.*   @@192.0.2.1:10514"
@@ -38,8 +38,6 @@ def handle(name,cfg,cloud,log,args):
     def_dir = cfg.get('rsyslog_dir', DEF_DIR)
     def_fname = cfg.get('rsyslog_filename', DEF_FILENAME)
 
-    entries = cfg['rsyslog']
-
     files = [ ]
     elst = [ ]
     for ent in cfg['rsyslog']:
@@ -80,7 +78,7 @@ def handle(name,cfg,cloud,log,args):
         # it will also return failure on the attempt, so 'restarted'
         # won't get set
         log.debug("restarting rsyslog")
-        p = util.subp(['service', 'rsyslog', 'restart'])
+        util.subp(['service', 'rsyslog', 'restart'])
         restarted = True
 
     except Exception as e:
diff --git a/cloudinit/CloudConfig/cc_runcmd.py b/cloudinit/CloudConfig/cc_runcmd.py
index f030980a..d255223b 100644
--- a/cloudinit/CloudConfig/cc_runcmd.py
+++ b/cloudinit/CloudConfig/cc_runcmd.py
@@ -15,10 +15,10 @@
 #
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
-import cloudinit
+
 import cloudinit.util as util
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,cloud,log,_args):
     if not cfg.has_key("runcmd"):
         return
     outfile="%s/runcmd" % cloud.get_ipath('scripts')
diff --git a/cloudinit/CloudConfig/cc_scripts_per_boot.py b/cloudinit/CloudConfig/cc_scripts_per_boot.py
index 4e407fb7..fb643c6d 100644
--- a/cloudinit/CloudConfig/cc_scripts_per_boot.py
+++ b/cloudinit/CloudConfig/cc_scripts_per_boot.py
@@ -15,14 +15,15 @@
 #
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import cloudinit.util as util
-from cloudinit.CloudConfig import per_once, per_always, per_instance
-from cloudinit import get_cpath, get_ipath_cur
+from cloudinit.CloudConfig import per_always
+from cloudinit import get_cpath
 
 frequency = per_always
 runparts_path = "%s/%s" % (get_cpath(), "scripts/per-boot")
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,_cfg,_cloud,log,_args):
     try:
         util.runparts(runparts_path)
     except:
diff --git a/cloudinit/CloudConfig/cc_scripts_per_instance.py b/cloudinit/CloudConfig/cc_scripts_per_instance.py
index 22b41185..b0f0601a 100644
--- a/cloudinit/CloudConfig/cc_scripts_per_instance.py
+++ b/cloudinit/CloudConfig/cc_scripts_per_instance.py
@@ -15,14 +15,15 @@
 #
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import cloudinit.util as util
-from cloudinit.CloudConfig import per_once, per_always, per_instance
-from cloudinit import get_cpath, get_ipath_cur
+from cloudinit.CloudConfig import per_instance
+from cloudinit import get_cpath
 
 frequency = per_instance
 runparts_path = "%s/%s" % (get_cpath(), "scripts/per-instance")
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,_cfg,_cloud,log,_args):
     try:
         util.runparts(runparts_path)
     except:
diff --git a/cloudinit/CloudConfig/cc_scripts_per_once.py b/cloudinit/CloudConfig/cc_scripts_per_once.py
index 9d752325..2ab81840 100644
--- a/cloudinit/CloudConfig/cc_scripts_per_once.py
+++ b/cloudinit/CloudConfig/cc_scripts_per_once.py
@@ -15,14 +15,15 @@
 #
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import cloudinit.util as util
-from cloudinit.CloudConfig import per_once, per_always, per_instance
-from cloudinit import get_cpath, get_ipath_cur
+from cloudinit.CloudConfig import per_once
+from cloudinit import get_cpath
 
 frequency = per_once
 runparts_path = "%s/%s" % (get_cpath(), "scripts/per-once")
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,_cfg,_cloud,log,_args):
     try:
         util.runparts(runparts_path)
     except:
diff --git a/cloudinit/CloudConfig/cc_scripts_user.py b/cloudinit/CloudConfig/cc_scripts_user.py
index bafecd23..9c7f2322 100644
--- a/cloudinit/CloudConfig/cc_scripts_user.py
+++ b/cloudinit/CloudConfig/cc_scripts_user.py
@@ -15,14 +15,15 @@
 #
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import cloudinit.util as util
-from cloudinit.CloudConfig import per_once, per_always, per_instance
-from cloudinit import get_cpath, get_ipath_cur
+from cloudinit.CloudConfig import per_instance
+from cloudinit import get_ipath_cur
 
 frequency = per_instance
 runparts_path = "%s/%s" % (get_ipath_cur(), "scripts")
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,_cfg,_cloud,log,_args):
     try:
         util.runparts(runparts_path)
     except:
diff --git a/cloudinit/CloudConfig/cc_set_hostname.py b/cloudinit/CloudConfig/cc_set_hostname.py
index bc190049..4f19b0c8 100644
--- a/cloudinit/CloudConfig/cc_set_hostname.py
+++ b/cloudinit/CloudConfig/cc_set_hostname.py
@@ -15,18 +15,18 @@
 #
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import cloudinit.util as util
-import subprocess
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,cloud,log,_args):
     if util.get_cfg_option_bool(cfg,"preserve_hostname",False):
         log.debug("preserve_hostname is set. not setting hostname")
         return(True)
 
-    ( hostname, fqdn ) = util.get_hostname_fqdn(cfg, cloud)
+    ( hostname, _fqdn ) = util.get_hostname_fqdn(cfg, cloud)
     try:
         set_hostname(hostname, log)
-    except Exception as e:
+    except Exception:
         util.logexc(log)
         log.warn("failed to set hostname to %s\n", hostname)
 
diff --git a/cloudinit/CloudConfig/cc_set_passwords.py b/cloudinit/CloudConfig/cc_set_passwords.py
index edfbaeeb..07e3ca1b 100644
--- a/cloudinit/CloudConfig/cc_set_passwords.py
+++ b/cloudinit/CloudConfig/cc_set_passwords.py
@@ -15,13 +15,13 @@
 #
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import cloudinit.util as util
-import subprocess
 import sys
 import random
 import string
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,_cloud,log,args):
     if len(args) != 0:
         # if run from command line, and give args, wipe the chpasswd['list']
         password = args[0]
@@ -115,7 +115,7 @@ def handle(name,cfg,cloud,log,args):
     return
 
 def rand_str(strlen=32, select_from=string.letters+string.digits):
-    return("".join([random.choice(select_from) for x in range(0, strlen)]))
+    return("".join([random.choice(select_from) for _x in range(0, strlen)]))
 
 def rand_user_password(pwlen=9):
     selfrom=(string.letters.translate(None,'loLOI') +
diff --git a/cloudinit/CloudConfig/cc_ssh.py b/cloudinit/CloudConfig/cc_ssh.py
index 9f5dc567..0aad2187 100644
--- a/cloudinit/CloudConfig/cc_ssh.py
+++ b/cloudinit/CloudConfig/cc_ssh.py
@@ -26,7 +26,7 @@ DISABLE_ROOT_OPTS="no-port-forwarding,no-agent-forwarding,no-X11-forwarding,comm
 
 global_log = None
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,cloud,log,_args):
     global global_log
     global_log = log
 
diff --git a/cloudinit/CloudConfig/cc_ssh_import_id.py b/cloudinit/CloudConfig/cc_ssh_import_id.py
index bf1314be..7e7a54a1 100644
--- a/cloudinit/CloudConfig/cc_ssh_import_id.py
+++ b/cloudinit/CloudConfig/cc_ssh_import_id.py
@@ -19,7 +19,7 @@ import cloudinit.util as util
 import subprocess
 import traceback
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,_cloud,log,args):
     if len(args) != 0:
         user = args[0]
         ids = [ ]
diff --git a/cloudinit/CloudConfig/cc_timezone.py b/cloudinit/CloudConfig/cc_timezone.py
index e8a453f9..26b2796d 100644
--- a/cloudinit/CloudConfig/cc_timezone.py
+++ b/cloudinit/CloudConfig/cc_timezone.py
@@ -15,16 +15,16 @@
 #
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 from cloudinit.CloudConfig import per_instance
 from cloudinit import util
-import subprocess
 import os.path
 import shutil
 
 frequency = per_instance
 tz_base = "/usr/share/zoneinfo"
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,_cloud,log,args):
     if len(args) != 0:
         timezone = args[0]
     else:
diff --git a/cloudinit/CloudConfig/cc_update_etc_hosts.py b/cloudinit/CloudConfig/cc_update_etc_hosts.py
index 1dc9c1e9..1c245e67 100644
--- a/cloudinit/CloudConfig/cc_update_etc_hosts.py
+++ b/cloudinit/CloudConfig/cc_update_etc_hosts.py
@@ -21,7 +21,7 @@ import StringIO
 
 frequency = per_always
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,cloud,log,_args):
     ( hostname, fqdn ) = util.get_hostname_fqdn(cfg, cloud)
 
     manage_hosts = util.get_cfg_option_bool(cfg,"manage_etc_hosts", False)
@@ -34,7 +34,7 @@ def handle(name,cfg,cloud,log,args):
 
             util.render_to_file('hosts', '/etc/hosts', \
                 { 'hostname' : hostname, 'fqdn' : fqdn })
-        except Exception as e:
+        except Exception:
             log.warn("failed to update /etc/hosts")
             raise
     elif manage_hosts == "localhost":
@@ -48,37 +48,37 @@ def handle(name,cfg,cloud,log,args):
             log.debug("not managing /etc/hosts")
 
 
-def update_etc_hosts(hostname, fqdn, log):
-     with open('/etc/hosts', 'r') as etchosts:
-         header = "# Added by cloud-init\n"
-         hosts_line = "127.0.1.1\t%s %s\n" % (fqdn, hostname)
-         need_write = False
-         need_change = True
-         new_etchosts = StringIO.StringIO()
-         for line in etchosts:
-             split_line = [s.strip() for s in line.split()]
-             if len(split_line) < 2:
+def update_etc_hosts(hostname, fqdn, _log):
+    with open('/etc/hosts', 'r') as etchosts:
+        header = "# Added by cloud-init\n"
+        hosts_line = "127.0.1.1\t%s %s\n" % (fqdn, hostname)
+        need_write = False
+        need_change = True
+        new_etchosts = StringIO.StringIO()
+        for line in etchosts:
+            split_line = [s.strip() for s in line.split()]
+            if len(split_line) < 2:
                 new_etchosts.write(line)
                 continue
-             if line == header:
+            if line == header:
                 continue
-             ip, hosts = split_line[0], split_line[1:]
-             if ip == "127.0.1.1":
-                 if sorted([hostname, fqdn]) == sorted(hosts):
-                     need_change = False
-                 if need_change == True:
-                     line = "%s%s" % (header, hosts_line)
-                     need_change = False
-                     need_write = True
-             new_etchosts.write(line)
-         etchosts.close()
-         if need_change == True:
-             new_etchosts.write("%s%s" % (header, hosts_line))
-             need_write = True
-         if need_write == True:
-             new_etcfile = open ('/etc/hosts','wb')
-             new_etcfile.write(new_etchosts.getvalue())
-             new_etcfile.close()
-         new_etchosts.close()
-     return
+            ip, hosts = split_line[0], split_line[1:]
+            if ip == "127.0.1.1":
+                if sorted([hostname, fqdn]) == sorted(hosts):
+                    need_change = False
+                if need_change == True:
+                    line = "%s%s" % (header, hosts_line)
+                    need_change = False
+                    need_write = True
+            new_etchosts.write(line)
+        etchosts.close()
+        if need_change == True:
+            new_etchosts.write("%s%s" % (header, hosts_line))
+            need_write = True
+        if need_write == True:
+            new_etcfile = open ('/etc/hosts','wb')
+            new_etcfile.write(new_etchosts.getvalue())
+            new_etcfile.close()
+        new_etchosts.close()
+    return
 
diff --git a/cloudinit/CloudConfig/cc_update_hostname.py b/cloudinit/CloudConfig/cc_update_hostname.py
index 3f55c73b..4bc1cb2b 100644
--- a/cloudinit/CloudConfig/cc_update_hostname.py
+++ b/cloudinit/CloudConfig/cc_update_hostname.py
@@ -22,16 +22,16 @@ from cloudinit.CloudConfig import per_always
 
 frequency = per_always
 
-def handle(name,cfg,cloud,log,args):
+def handle(_name,cfg,cloud,log,_args):
     if util.get_cfg_option_bool(cfg,"preserve_hostname",False):
         log.debug("preserve_hostname is set. not updating hostname")
         return
 
-    ( hostname, fqdn ) = util.get_hostname_fqdn(cfg, cloud)
+    ( hostname, _fqdn ) = util.get_hostname_fqdn(cfg, cloud)
     try:
         prev ="%s/%s" % (cloud.get_cpath('data'),"previous-hostname")
         update_hostname(hostname, prev, log)
-    except Exception as e:
+    except Exception:
         log.warn("failed to set hostname\n")
         raise
 
diff --git a/cloudinit/DataSource.py b/cloudinit/DataSource.py
index 06061a2e..ac79f757 100644
--- a/cloudinit/DataSource.py
+++ b/cloudinit/DataSource.py
@@ -69,7 +69,7 @@ class DataSource:
         if isinstance(self.metadata['public-keys'], str):
             return([self.metadata['public-keys'],])
             
-        for keyname, klist in self.metadata['public-keys'].items():
+        for _keyname, klist in self.metadata['public-keys'].items():
             # lp:506332 uec metadata service responds with
             # data that makes boto populate a string for 'klist' rather
             # than a list.
@@ -82,7 +82,7 @@ class DataSource:
 
         return(keys)
 
-    def device_name_to_device(self, name):
+    def device_name_to_device(self, _name):
         # translate a 'name' to a device
         # the primary function at this point is on ec2
         # to consult metadata service, that has
@@ -157,7 +157,9 @@ class DataSource:
 #   ie, pkglist=[ "foo", "" ]
 #     will first try to load foo.DataSource<item>
 #     then DataSource<item>
-def list_sources(cfg_list, depends, pkglist=[]):
+def list_sources(cfg_list, depends, pkglist=None):
+    if pkglist is None:
+        pkglist = []
     retlist = []
     for ds_coll in cfg_list:
         for pkg in pkglist:
@@ -197,8 +199,8 @@ def is_ipv4(instr):
         return False
 
     try:
-        r = filter(lambda x: int(x) < 256 and x > 0, toks)
+        toks = [x for x in toks if (int(x) < 256 and int(x) > 0)]
     except:
         return False
 
-    return True
+    return (len(toks) == 4)
diff --git a/cloudinit/DataSourceEc2.py b/cloudinit/DataSourceEc2.py
index aee10ffa..9191e647 100644
--- a/cloudinit/DataSourceEc2.py
+++ b/cloudinit/DataSourceEc2.py
@@ -18,16 +18,13 @@
 
 import DataSource
 
-from cloudinit import seeddir, log
+from cloudinit import seeddir, log  # pylint: disable=W0611
 import cloudinit.util as util
 import socket
 import urllib2
 import time
-import sys
 import boto.utils as boto_utils
 import os.path
-import errno
-import urlparse
 
 class DataSourceEc2(DataSource.DataSource):
     api_ver  = '2009-04-04'
@@ -92,7 +89,7 @@ class DataSourceEc2(DataSource.DataSource):
         max_wait = 120
         try:
             max_wait = int(mcfg.get("max_wait",max_wait))
-        except Exception as e:
+        except Exception:
             util.logexc(log)
             log.warn("Failed to get max wait. using %s" % max_wait)
 
@@ -102,7 +99,7 @@ class DataSourceEc2(DataSource.DataSource):
         timeout = 50
         try:
             timeout = int(mcfg.get("timeout",timeout))
-        except Exception as e:
+        except Exception:
             util.logexc(log)
             log.warn("Failed to get timeout, using %s" % timeout)
 
@@ -229,7 +226,6 @@ def wait_for_metadata_service(urls, max_wait=None, timeout=None, status_cb=None)
     starttime = time.time()
 
     sleeptime = 1
-    timeout_orig = timeout
 
     if status_cb == None:
         def status_cb(msg): return
diff --git a/cloudinit/DataSourceNoCloud.py b/cloudinit/DataSourceNoCloud.py
index 956b1a5e..2f4bd604 100644
--- a/cloudinit/DataSourceNoCloud.py
+++ b/cloudinit/DataSourceNoCloud.py
@@ -18,12 +18,8 @@
 
 import DataSource
 
-from cloudinit import seeddir, log
+from cloudinit import seeddir, log  # pylint: disable=W0611
 import cloudinit.util as util
-import sys
-import os.path
-import os
-import errno
 
 class DataSourceNoCloud(DataSource.DataSource):
     metadata = None
@@ -94,7 +90,7 @@ class DataSourceNoCloud(DataSource.DataSource):
 
         md = util.mergedict(md,defaults)
         self.seed = ",".join(found)
-        self.metadata = md;
+        self.metadata = md
         self.userdata_raw = ud
         return True
 
diff --git a/cloudinit/DataSourceOVF.py b/cloudinit/DataSourceOVF.py
index a9089d70..1c510688 100644
--- a/cloudinit/DataSourceOVF.py
+++ b/cloudinit/DataSourceOVF.py
@@ -23,9 +23,7 @@ import cloudinit.util as util
 import sys
 import os.path
 import os
-import errno
 from xml.dom import minidom
-from xml.dom import Node
 import base64
 import re
 import tempfile
@@ -66,13 +64,13 @@ class DataSourceOVF(DataSource.DataSource):
             np = { 'iso' : transport_iso9660, 
                    'vmware-guestd' : transport_vmware_guestd, }
             for name, transfunc in np.iteritems():
-                (contents, dev, fname) = transfunc()
+                (contents, _dev, _fname) = transfunc()
                 if contents: break
 
             if contents:
                 (md, ud, cfg) = read_ovf_environment(contents)
                 self.environment = contents
-                found.append(name)
+                found.append(name)  # pylint: disable=W0631
 
         # There was no OVF transports found
         if len(found) == 0:
@@ -99,7 +97,7 @@ class DataSourceOVF(DataSource.DataSource):
 
         md = util.mergedict(md,defaults)
         self.seed = ",".join(found)
-        self.metadata = md;
+        self.metadata = md
         self.userdata_raw = ud
         self.cfg = cfg
         return True
@@ -173,7 +171,7 @@ def transport_iso9660(require_iso=False):
 
     mounted = { }
     for mpline in mounts:
-        (dev,mp,fstype,opts,freq,passno) = mpline.split()
+        (dev,mp,fstype,_opts,_freq,_passno) = mpline.split()
         mounted[dev]=(dev,fstype,mp,False)
         mp = mp.replace("\\040"," ")
         if fstype != "iso9660" and require_iso: continue
diff --git a/cloudinit/SshUtil.py b/cloudinit/SshUtil.py
index fdd3bb27..125ca618 100644
--- a/cloudinit/SshUtil.py
+++ b/cloudinit/SshUtil.py
@@ -46,7 +46,7 @@ class AuthKeyEntry():
                         elif curc == '"':
                             quoted = not quoted
                         i = i + 1
-                except IndexError as e:
+                except IndexError:
                     self.is_comment = True
                     return()
 
@@ -54,7 +54,7 @@ class AuthKeyEntry():
                     self.options = ent[0:i]
                     (self.keytype, self.base64, self.comment) = \
                         ent[i+1:].split(None,3)
-                except ValueError as e:
+                except ValueError:
                     # we did not understand this line
                     self.is_comment = True
 
@@ -84,7 +84,7 @@ def update_authorized_keys(fname, keys):
         fp = open(fname, "r")
         lines = fp.readlines() # lines have carriage return
         fp.close()
-    except IOError as e:
+    except IOError:
         lines = [ ]
 
     ka_stats = { } # keys_added status
@@ -133,7 +133,7 @@ def setup_user_keys(keys, user, key_prefix, log=None):
         akeys = akeys.replace("%h", pwent.pw_dir)
         akeys = akeys.replace("%u", user)
         authorized_keys = akeys
-    except Exception as e:
+    except Exception:
         authorized_keys = '%s/.ssh/authorized_keys' % pwent.pw_dir
         if log:
             util.logexc(log)
diff --git a/cloudinit/UserDataHandler.py b/cloudinit/UserDataHandler.py
index 541ee87a..14aea58b 100644
--- a/cloudinit/UserDataHandler.py
+++ b/cloudinit/UserDataHandler.py
@@ -20,12 +20,10 @@ import email
 from email.mime.multipart import MIMEMultipart
 from email.mime.text import MIMEText
 from email.mime.base import MIMEBase
-from email import encoders
 import yaml
 import cloudinit
 import cloudinit.util as util
 import hashlib
-import os
 import urllib
 
 starts_with_mappings={
@@ -39,15 +37,15 @@ starts_with_mappings={
     '#cloud-config-archive' : 'text/cloud-config-archive',
 }
 
-# if 'str' is compressed return decompressed otherwise return it
-def decomp_str(str):
+# if 'string' is compressed return decompressed otherwise return it
+def decomp_str(string):
     import StringIO
     import gzip
     try:
-        uncomp = gzip.GzipFile(None,"rb",1,StringIO.StringIO(str)).read()
+        uncomp = gzip.GzipFile(None,"rb",1,StringIO.StringIO(string)).read()
         return(uncomp)
     except:
-        return(str)
+        return(string)
 
 def do_include(content, appendmsg):
     import os
@@ -79,7 +77,7 @@ def do_include(content, appendmsg):
                 content = urllib.urlopen(line).read()
                 if includeonce:
                     util.write_file(includeonce_filename, content, mode=0600)
-        except Exception as e:
+        except Exception:
             raise
 
         process_includes(message_from_string(decomp_str(content)), appendmsg)
@@ -190,9 +188,10 @@ def process_includes(msg, appendmsg=None):
 
         _attach_part(appendmsg, part)
 
-def message_from_string(data, headers={}):
+def message_from_string(data, headers=None):
+    if headers is None:
+        headers = {}
     if "mime-version:" in data[0:4096].lower():
-        was_mime = True
         msg = email.message_from_string(data)
         for (key,val) in headers.items():
             if key in msg:
@@ -200,7 +199,6 @@ def message_from_string(data, headers={}):
             else:
                 msg[key] = val
     else:
-        was_mime = False
         mtype = headers.get("Content-Type","text/plain")
         maintype, subtype = mtype.split("/", 1)
         msg = MIMEBase(maintype, subtype, *headers)
diff --git a/cloudinit/__init__.py b/cloudinit/__init__.py
index d01d443d..d74a0f1f 100644
--- a/cloudinit/__init__.py
+++ b/cloudinit/__init__.py
@@ -115,6 +115,8 @@ class CloudInit:
     old_conffile = '/etc/ec2-init/ec2-config.cfg'
     ds_deps = [ DataSource.DEP_FILESYSTEM, DataSource.DEP_NETWORK ]
     datasource = None
+    cloud_config_str = ''
+    datasource_name = ''
 
     builtin_handlers = [ ]
 
@@ -137,7 +139,7 @@ class CloudInit:
 
         try:
             conf = util.get_base_cfg(self.sysconfig,cfg_builtin, parsed_cfgs)
-        except Exception as e:
+        except Exception:
             conf = get_builtin_cfg()
 
         # support reading the old ConfigObj format file and merging
@@ -176,7 +178,7 @@ class CloudInit:
                 
         try:
             f=open(cache, "wb")
-            data = cPickle.dump(self.datasource,f)
+            cPickle.dump(self.datasource,f)
             f.close()
             os.chmod(cache,0400)
         except:
@@ -191,7 +193,8 @@ class CloudInit:
 
         cfglist=self.cfg['datasource_list']
         dslist = list_sources(cfglist, self.ds_deps)
-        dsnames = map(lambda f: f.__name__, dslist)
+        dsnames = [f.__name__ for f in dslist]
+
         log.debug("searching for data source in %s" % dsnames)
         for cls in dslist:
             ds = cls.__name__
@@ -205,7 +208,6 @@ class CloudInit:
             except Exception as e:
                 log.warn("get_data of %s raised %s" % (ds,e))
                 util.logexc(log)
-                pass
         msg = "Did not find data source. searched classes: %s" % dsnames
         log.debug(msg)
         raise DataSourceNotFoundException(msg)
@@ -298,7 +300,9 @@ class CloudInit:
     # if that does not exist, then call 'func' with given 'args'
     # if 'clear_on_fail' is True and func throws an exception
     #  then remove the lock (so it would run again)
-    def sem_and_run(self,semname,freq,func,args=[],clear_on_fail=False):
+    def sem_and_run(self,semname,freq,func,args=None,clear_on_fail=False):
+        if args is None:
+            args = []
         if self.sem_has_run(semname,freq):
             log.debug("%s already ran %s", semname, freq)
             return False
@@ -360,12 +364,12 @@ class CloudInit:
 
         # give callbacks opportunity to finalize
         called = [ ]
-        for (mtype, mod) in part_handlers.iteritems():
+        for (_mtype, mod) in part_handlers.iteritems():
             if mod in called:
                 continue
             handler_call_end(mod, data, frequency)
 
-    def handle_user_script(self,data,ctype,filename,payload, frequency):
+    def handle_user_script(self,_data,ctype,filename,payload, _frequency):
         if ctype == "__end__": return
         if ctype == "__begin__":
             # maybe delete existing things here
@@ -376,7 +380,7 @@ class CloudInit:
         util.write_file("%s/%s" % 
             (scriptsdir,filename), util.dos2unix(payload), 0700)
 
-    def handle_upstart_job(self,data,ctype,filename,payload, frequency):
+    def handle_upstart_job(self,_data,ctype,filename,payload, frequency):
         # upstart jobs are only written on the first boot
         if frequency != per_instance:
             return
@@ -388,7 +392,7 @@ class CloudInit:
         util.write_file("%s/%s" % ("/etc/init",filename),
             util.dos2unix(payload), 0644)
 
-    def handle_cloud_config(self,data,ctype,filename,payload, frequency):
+    def handle_cloud_config(self,_data,ctype,filename,payload, _frequency):
         if ctype == "__begin__":
             self.cloud_config_str=""
             return
@@ -408,7 +412,7 @@ class CloudInit:
 
         self.cloud_config_str+="\n#%s\n%s" % (filename,payload)
 
-    def handle_cloud_boothook(self,data,ctype,filename,payload, frequency):
+    def handle_cloud_boothook(self,_data,ctype,filename,payload, _frequency):
         if ctype == "__end__": return
         if ctype == "__begin__": return
 
@@ -425,7 +429,7 @@ class CloudInit:
         try:
             env=os.environ.copy()
             env['INSTANCE_ID']= self.datasource.get_instance_id()
-            ret = subprocess.check_call([filepath], env=env)
+            subprocess.check_call([filepath], env=env)
         except subprocess.CalledProcessError as e:
             log.error("boothooks script %s returned %i" %
                 (filepath,e.returncode))
@@ -538,7 +542,7 @@ def handler_handle_part(mod, data, ctype, filename, payload, frequency):
     else:
         mod.handle_part(data, ctype, filename, payload, frequency)
 
-def partwalker_handle_handler(pdata, ctype, filename, payload):
+def partwalker_handle_handler(pdata, _ctype, _filename, payload):
 
     curcount = pdata['handlercount']
     modname  = 'part-handler-%03d' % curcount
diff --git a/cloudinit/netinfo.py b/cloudinit/netinfo.py
index 3ba922e8..9ca72b77 100644
--- a/cloudinit/netinfo.py
+++ b/cloudinit/netinfo.py
@@ -24,7 +24,7 @@ def netdev_info():
             if toks[i] == "hwaddr":
                 try:
                     devs[curdev]["hwaddr"] = toks[i+1]
-                except IndexError as e:
+                except IndexError:
                     pass
             for field in ("addr", "bcast", "mask"):
                 target = "%s%s" % (field, fieldpost)
@@ -33,7 +33,7 @@ def netdev_info():
                 if toks[i] == "%s:" % field:
                     try:
                         devs[curdev][target] = toks[i+1]
-                    except IndexError as e:
+                    except IndexError:
                         pass
                 elif toks[i].startswith("%s:" % field):
                     devs[curdev][target] = toks[i][len(field)+1:]
@@ -61,23 +61,23 @@ def debug_info(pre="ci-info: "):
     lines = [ ]
     try:
         netdev = netdev_info()
-    except Exception as e:
+    except Exception:
         lines.append("netdev_info failed!")
         netdev = {}
     for (dev, d) in netdev.iteritems():
         lines.append("%s%-6s: %i %-15s %-15s %s" %
             (pre, dev, d["up"], d["addr"],d["mask"], d["hwaddr"]))
     try:
-       routes = route_info()
-    except Exception as e:
-       lines.append("route_info failed")
-       routes = []
+        routes = route_info()
+    except Exception:
+        lines.append("route_info failed")
+        routes = []
     n = 0
     for r in routes:
-       lines.append("%sroute-%d: %-15s %-15s %-15s %-6s %s" %
-          (pre, n, r[0], r[1], r[2], r[7], r[3]))
-       n = n+1
+        lines.append("%sroute-%d: %-15s %-15s %-15s %-6s %s" %
+            (pre, n, r[0], r[1], r[2], r[7], r[3]))
+        n = n+1
     return('\n'.join(lines))
 
 if __name__ == '__main__':
-   print debug_info()
+    print debug_info()
diff --git a/cloudinit/util.py b/cloudinit/util.py
index de95ec79..5bf8e8b2 100644
--- a/cloudinit/util.py
+++ b/cloudinit/util.py
@@ -39,10 +39,10 @@ except ImportError:
 
 def read_conf(fname):
     try:
-	    stream = open(fname,"r")
-	    conf = yaml.load(stream)
-	    stream.close()
-	    return conf
+        stream = open(fname,"r")
+        conf = yaml.load(stream)
+        stream.close()
+        return conf
     except IOError as e:
         if e.errno == errno.ENOENT:
             return { }
@@ -111,19 +111,19 @@ def mergedict(src,cand):
                 src[k] = mergedict(src[k],v)
     return src
 
-def write_file(file,content,mode=0644,omode="wb"):
-        try:
-            os.makedirs(os.path.dirname(file))
-        except OSError as e:
-            if e.errno != errno.EEXIST:
-                raise e
+def write_file(filename,content,mode=0644,omode="wb"):
+    try:
+        os.makedirs(os.path.dirname(filename))
+    except OSError as e:
+        if e.errno != errno.EEXIST:
+            raise e
 
-        f=open(file,omode)
-        if mode != None:
-            os.chmod(file,mode)
-        f.write(content)
-        f.close()
-        restorecon_if_possible(file)
+    f=open(filename,omode)
+    if mode != None:
+        os.chmod(filename,mode)
+    f.write(content)
+    f.close()
+    restorecon_if_possible(filename)
 
 def restorecon_if_possible(path, recursive=False):
     if HAVE_LIBSELINUX and selinux.is_selinux_enabled():
@@ -131,20 +131,20 @@ def restorecon_if_possible(path, recursive=False):
 
 # get keyid from keyserver
 def getkeybyid(keyid,keyserver):
-   shcmd="""
-   k=${1} ks=${2};
-   exec 2>/dev/null
-   [ -n "$k" ] || exit 1;
-   armour=$(gpg --list-keys --armour "${k}")
-   if [ -z "${armour}" ]; then
-      gpg --keyserver ${ks} --recv $k >/dev/null &&
-         armour=$(gpg --export --armour "${k}") &&
-         gpg --batch --yes --delete-keys "${k}"
-   fi
-   [ -n "${armour}" ] && echo "${armour}"
-   """
-   args=['sh', '-c', shcmd, "export-gpg-keyid", keyid, keyserver]
-   return(subp(args)[0])
+    shcmd="""
+    k=${1} ks=${2};
+    exec 2>/dev/null
+    [ -n "$k" ] || exit 1;
+    armour=$(gpg --list-keys --armour "${k}")
+    if [ -z "${armour}" ]; then
+       gpg --keyserver ${ks} --recv $k >/dev/null &&
+          armour=$(gpg --export --armour "${k}") &&
+          gpg --batch --yes --delete-keys "${k}"
+    fi
+    [ -n "${armour}" ] && echo "${armour}"
+    """
+    args=['sh', '-c', shcmd, "export-gpg-keyid", keyid, keyserver]
+    return(subp(args)[0])
 
 def runparts(dirp, skip_no_exist=True):
     if skip_no_exist and not os.path.isdir(dirp): return
@@ -159,10 +159,10 @@ def runparts(dirp, skip_no_exist=True):
         raise subprocess.CalledProcessError(sp.returncode,cmd)
     return
 
-def subp(args, input=None):
+def subp(args, input_=None):
     sp = subprocess.Popen(args, stdout=subprocess.PIPE,
         stderr=subprocess.PIPE, stdin=subprocess.PIPE)
-    out,err = sp.communicate(input)
+    out,err = sp.communicate(input_)
     if sp.returncode is not 0:
         raise subprocess.CalledProcessError(sp.returncode,args, (out,err))
     return(out,err)
@@ -238,7 +238,9 @@ def logexc(log,lvl=logging.DEBUG):
 class RecursiveInclude(Exception):
     pass
 
-def read_file_with_includes(fname, rel = ".", stack=[], patt = None):
+def read_file_with_includes(fname, rel = ".", stack=None, patt = None):
+    if stack is None:
+        stack = []
     if not fname.startswith("/"):
         fname = os.sep.join((rel, fname))
 
@@ -264,7 +266,6 @@ def read_file_with_includes(fname, rel = ".", stack=[], patt = None):
     stack.append(fname)
 
     cur = 0
-    clen = len(contents)
     while True:
         match = patt.search(contents[cur:])
         if not match: break
@@ -282,7 +283,7 @@ def read_file_with_includes(fname, rel = ".", stack=[], patt = None):
             else:
                 raise
         contents = contents[0:loc] + inc_contents + contents[endl+1:]
-	cur = loc + len(inc_contents)
+        cur = loc + len(inc_contents)
     stack.pop()
     return(contents)
 
@@ -291,10 +292,10 @@ def read_conf_d(confd):
     confs = sorted(os.listdir(confd),reverse=True)
     
     # remove anything not ending in '.cfg'
-    confs = filter(lambda f: f.endswith(".cfg"), confs)
+    confs = [f for f in confs if f.endswith(".cfg")]
 
     # remove anything not a file
-    confs = filter(lambda f: os.path.isfile("%s/%s" % (confd,f)),confs)
+    confs = [f for f in confs if os.path.isfile("%s/%s" % (confd,f))]
 
     cfg = { }
     for conf in confs:
@@ -377,17 +378,17 @@ def ensure_dirs(dirlist, mode=0755):
         os.chmod(d, mode)
 
 def chownbyname(fname,user=None,group=None):
-   uid = -1
-   gid = -1
-   if user == None and group == None: return
-   if user:
-      import pwd
-      uid = pwd.getpwnam(user).pw_uid
-   if group:
-      import grp
-      gid = grp.getgrnam(group).gr_gid
-
-   os.chown(fname,uid,gid)
+    uid = -1
+    gid = -1
+    if user == None and group == None: return
+    if user:
+        import pwd
+        uid = pwd.getpwnam(user).pw_uid
+    if group:
+        import grp
+        gid = grp.getgrnam(group).gr_gid
+
+    os.chown(fname,uid,gid)
 
 def readurl(url, data=None, timeout=None):
     openargs = { }
@@ -422,11 +423,11 @@ def shellify(cmdlist):
             content="%s%s\n" % ( content, str(args) )
     return content
 
-def dos2unix(input):
+def dos2unix(string):
     # find first end of line
-    pos = input.find('\n')
-    if pos <= 0 or input[pos-1] != '\r': return(input)
-    return(input.replace('\r\n','\n'))
+    pos = string.find('\n')
+    if pos <= 0 or string[pos-1] != '\r': return(string)
+    return(string.replace('\r\n','\n'))
 
 def islxc():
     # is this host running lxc?
@@ -443,7 +444,7 @@ def islxc():
         # we're inside a container. otherwise, no
         sp = subprocess.Popen(['lxc-is-container'], stdout=subprocess.PIPE,
                               stderr=subprocess.PIPE)
-        out,err = sp.communicate(None)
+        sp.communicate(None)
         return(sp.returncode == 0)
     except OSError as e:
         if e.errno != errno.ENOENT:
@@ -507,7 +508,7 @@ def is_resolvable(name):
     try:
         socket.getaddrinfo(name, None)
         return True
-    except socket.gaierror as e:
+    except socket.gaierror:
         return False
 
 def is_resolvable_url(url):
@@ -520,20 +521,20 @@ def search_for_mirror(candidates):
         try:
             if is_resolvable_url(cand):
                 return cand
-        except Exception as e:
+        except Exception:
             raise
 
     return None
 
 def close_stdin():
-   """
-   reopen stdin as /dev/null so even subprocesses or other os level things get
-   /dev/null as input.
-
-   if _CLOUD_INIT_SAVE_STDIN is set in environment to a non empty or '0' value
-   then input will not be closed (only useful potentially for debugging).
-   """
-   if os.environ.get("_CLOUD_INIT_SAVE_STDIN") in ("", "0", False):
-      return
-   with open(os.devnull) as fp:
-       os.dup2(fp.fileno(), sys.stdin.fileno())
+    """
+    reopen stdin as /dev/null so even subprocesses or other os level things get
+    /dev/null as input.
+
+    if _CLOUD_INIT_SAVE_STDIN is set in environment to a non empty or '0' value
+    then input will not be closed (only useful potentially for debugging).
+    """
+    if os.environ.get("_CLOUD_INIT_SAVE_STDIN") in ("", "0", False):
+        return
+    with open(os.devnull) as fp:
+        os.dup2(fp.fileno(), sys.stdin.fileno())