replace unintuitive reduce() calls with slightly less unintuitive chain() calls

3 files changed, 16 insertions, 19 deletions

diff --git a/src/lib/Bcfg2/Server/Core.py b/src/lib/Bcfg2/Server/Core.py
index 040036fb2..37da4a4b6 100644
--- a/src/lib/Bcfg2/Server/Core.py
+++ b/src/lib/Bcfg2/Server/Core.py
@@ -16,7 +16,8 @@ import Bcfg2.Logger
 import Bcfg2.Server.FileMonitor
 from Bcfg2.Cache import Cache
 import Bcfg2.Statistics
-from Bcfg2.Compat import xmlrpclib, reduce  # pylint: disable=W0622
+from itertools import chain
+from Bcfg2.Compat import xmlrpclib  # pylint: disable=W0622
 from Bcfg2.Server.Plugin import PluginInitError, PluginExecutionError, \
     track_statistics
 
@@ -493,9 +494,8 @@ class BaseCore(object):
         :type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata
         :returns: list of :class:`lxml.etree._Element` objects
         """
-        structures = reduce(lambda x, y: x + y,
-                            [struct.BuildStructures(metadata)
-                             for struct in self.structures], [])
+        structures = list(chain(*[struct.BuildStructures(metadata)
+                                  for struct in self.structures]))
         sbundles = [b.get('name') for b in structures if b.tag == 'Bundle']
         missing = [b for b in metadata.bundles if b not in sbundles]
         if missing:
diff --git a/src/lib/Bcfg2/Server/Plugins/Base.py b/src/lib/Bcfg2/Server/Plugins/Base.py
index 66515ede2..d662da60a 100644
--- a/src/lib/Bcfg2/Server/Plugins/Base.py
+++ b/src/lib/Bcfg2/Server/Plugins/Base.py
@@ -2,9 +2,8 @@
 
 import copy
 import lxml.etree
-import sys
-from Bcfg2.Compat import reduce
 import Bcfg2.Server.Plugin
+from itertools import chain
 
 
 class Base(Bcfg2.Server.Plugin.Plugin,
@@ -18,7 +17,6 @@ class Base(Bcfg2.Server.Plugin.Plugin,
     __child__ = Bcfg2.Server.Plugin.StructFile
     deprecated = True
 
-    """Base creates independent clauses based on client metadata."""
     def __init__(self, core, datastore):
         Bcfg2.Server.Plugin.Plugin.__init__(self, core, datastore)
         Bcfg2.Server.Plugin.Structure.__init__(self)
@@ -33,8 +31,8 @@ class Base(Bcfg2.Server.Plugin.Plugin,
     def BuildStructures(self, metadata):
         """Build structures for client described by metadata."""
         ret = lxml.etree.Element("Independent", version='2.0')
-        fragments = reduce(lambda x, y: x + y,
-                           [base.Match(metadata) for base
-                            in list(self.entries.values())], [])
-        [ret.append(copy.copy(frag)) for frag in fragments]
+        fragments = list(chain(*[base.Match(metadata)
+                                 for base in list(self.entries.values())]))
+        for frag in fragments:
+            ret.append(copy.copy(frag))
         return [ret]
diff --git a/src/lib/Bcfg2/Server/Plugins/SSHbase.py b/src/lib/Bcfg2/Server/Plugins/SSHbase.py
index feb76aa57..c7db67301 100644
--- a/src/lib/Bcfg2/Server/Plugins/SSHbase.py
+++ b/src/lib/Bcfg2/Server/Plugins/SSHbase.py
@@ -7,10 +7,11 @@ import socket
 import shutil
 import logging
 import tempfile
+from itertools import chain
 from subprocess import Popen, PIPE
 import Bcfg2.Server.Plugin
 from Bcfg2.Server.Plugin import PluginExecutionError
-from Bcfg2.Compat import any, u_str, reduce, b64encode  # pylint: disable=W0622
+from Bcfg2.Compat import any, u_str, b64encode  # pylint: disable=W0622
 
 LOGGER = logging.getLogger(__name__)
 
@@ -200,15 +201,13 @@ class SSHbase(Bcfg2.Server.Plugin.Plugin,
                     if specific.hostname and specific.hostname in names:
                         hostnames = names[specific.hostname]
                     elif specific.group:
-                        hostnames = \
-                            reduce(lambda x, y: x + y,
-                                   [names[cmeta.hostname]
-                                    for cmeta in \
-                                    mquery.by_groups([specific.group])], [])
+                        hostnames = list(chain(
+                                *[names[cmeta.hostname]
+                                  for cmeta in \
+                                      mquery.by_groups([specific.group])]))
                     elif specific.all:
                         # a generic key for all hosts?  really?
-                        hostnames = reduce(lambda x, y: x + y,
-                                           list(names.values()), [])
+                        hostnames = list(chain(*list(names.values())))
                     if not hostnames:
                         if specific.hostname:
                             key = specific.hostname