diff --git a/lib/spack/spack/architecture.py b/lib/spack/spack/architecture.py
index 2701fa9a0c5..6c3c478f91e 100644
--- a/lib/spack/spack/architecture.py
+++ b/lib/spack/spack/architecture.py
@@ -76,7 +76,6 @@
 will be responsible for compiler detection.
 """
 import os
-import imp
 import inspect
 
 from llnl.util.lang import memoized, list_modules, key_ordering
@@ -206,15 +205,12 @@ def detect(self):
         """
         raise NotImplementedError()
 
-
     def __repr__(self):
         return self.__str__()
 
-
     def __str__(self):
         return self.name
 
-
     def _cmp_key(self):
         t_keys = ''.join(str(t._cmp_key()) for t in
                          sorted(self.targets.values()))
@@ -285,7 +281,7 @@ def find_compilers(self, *paths):
 
         # ensure all the version calls we made are cached in the parent
         # process, as well.  This speeds up Spack a lot.
-        clist = reduce(lambda x, y: x+y, compiler_lists)
+        clist = reduce(lambda x, y: x + y, compiler_lists)
         return clist
 
     def find_compiler(self, cmp_cls, *path):
@@ -326,7 +322,7 @@ def find_compiler(self, cmp_cls, *path):
 
                 # prefer the one with more compilers.
                 prev_paths = [prev.cc, prev.cxx, prev.f77, prev.fc]
-                newcount = len([p for p in paths       if p is not None])
+                newcount = len([p for p in paths if p is not None])
                 prevcount = len([p for p in prev_paths if p is not None])
 
                 # Don't add if it's not an improvement over prev compiler.
@@ -343,6 +339,7 @@ def to_dict(self):
         d['version'] = self.version
         return d
 
+
 @key_ordering
 class Arch(object):
     """Architecture is now a class to help with setting attributes.
@@ -383,11 +380,9 @@ def __str__(self):
         else:
             return ''
 
-
     def __contains__(self, string):
         return string in str(self)
 
-
     def _cmp_key(self):
         if isinstance(self.platform, Platform):
             platform = self.platform.name
@@ -430,7 +425,7 @@ def _operating_system_from_dict(os_name, plat=None):
     if isinstance(os_name, dict):
         name = os_name['name']
         version = os_name['version']
-        return plat.operating_system(name+version)
+        return plat.operating_system(name + version)
     else:
         return plat.operating_system(os_name)
 
diff --git a/lib/spack/spack/build_environment.py b/lib/spack/spack/build_environment.py
index 8e40e9883dc..fbcba08367b 100644
--- a/lib/spack/spack/build_environment.py
+++ b/lib/spack/spack/build_environment.py
@@ -248,7 +248,7 @@ def set_build_environment_variables(pkg, env, dirty=False):
         ci = join_path(item, 'case-insensitive')
         if os.path.isdir(ci):
             env_paths.append(ci)
-    
+
     for item in reversed(env_paths):
         env.prepend_path('PATH', item)
     env.set_path(SPACK_ENV_PATH, env_paths)