diff --git a/rel-eng/lorax_tito/__init__.py b/rel-eng/lorax_tito/__init__.py
index 05f2153d..04422735 100644
--- a/rel-eng/lorax_tito/__init__.py
+++ b/rel-eng/lorax_tito/__init__.py
@@ -1,3 +1,3 @@
 from lorax_tito.tagger import LoraxRHELTagger
 
-all = [LoraxRHELTagger]
+__all__ = ['LoraxRHELTagger']
diff --git a/src/bin/image-minimizer b/src/bin/image-minimizer
index f428d2e2..297d4e52 100755
--- a/src/bin/image-minimizer
+++ b/src/bin/image-minimizer
@@ -45,8 +45,8 @@ class ImageMinimizer:
     def add_directory(self, files, dirname):
         self.visited.add(dirname)
         for root, dirs, items in os.walk(dirname):
-            for dir in dirs:
-                self.visited.add(os.path.join(root, dir))
+            for _dir in dirs:
+                self.visited.add(os.path.join(root, _dir))
             for name in items:
                 files.add(os.path.join(root, name))
 
@@ -123,14 +123,14 @@ class ImageMinimizer:
                     os.remove(tag)
 
         #remove all empty directory. Every 8k counts!
-        for dir in sorted(self.visited, reverse=True):
-            if len(os.listdir(dir)) == 0:
+        for _dir in sorted(self.visited, reverse=True):
+            if len(os.listdir(_dir)) == 0:
                 if self.dryrun:
-                    print 'rm -rf ' + dir
+                    print 'rm -rf ' + _dir
                 else:
                     if self.verbose:
-                        print 'rm -rf ' + dir
-                    os.rmdir(dir)
+                        print 'rm -rf ' + _dir
+                    os.rmdir(_dir)
 
     def remove_rpm(self):
 
diff --git a/src/pylorax/output.py b/src/pylorax/output.py
index c5968594..f8179c6b 100644
--- a/src/pylorax/output.py
+++ b/src/pylorax/output.py
@@ -87,44 +87,44 @@ class LinuxTerminalOutput(object):
         if self._indent_level > 0:
             self._indent_level -= 1
 
-    def write(self, s, file=sys.stdout):
+    def write(self, s, fp=sys.stdout):
         if self._colors:
             s = self.__format(s)
         else:
             s = self.__raw(s)
 
-        file.write(s)
-        file.flush()
+        fp.write(s)
+        fp.flush()
 
-    def writeline(self, s, file=sys.stdout):
+    def writeline(self, s, fp=sys.stdout):
         s = "{0}{1}\n".format("    " * self._indent_level, s)
-        self.write(s, file=file)
+        self.write(s, fp=fp)
 
-    def critical(self, s, file=sys.stdout):
+    def critical(self, s, fp=sys.stdout):
         s = "** critical: {0}".format(s)
         if (self._output_level <= CRITICAL and
             self.__raw(s) not in self._ignored_messages):
-            self.writeline(s, file=file)
+            self.writeline(s, fp=fp)
 
-    def error(self, s, file=sys.stdout):
+    def error(self, s, fp=sys.stdout):
         s = "** error: {0}".format(s)
         if (self._output_level <= ERROR and
             self.__raw(s) not in self._ignored_messages):
-            self.writeline(s, file=file)
+            self.writeline(s, fp=fp)
 
-    def warning(self, s, file=sys.stdout):
+    def warning(self, s, fp=sys.stdout):
         s = "** warning: {0}".format(s)
         if (self._output_level <= WARNING and
             self.__raw(s) not in self._ignored_messages):
-            self.writeline(s, file=file)
+            self.writeline(s, fp=fp)
 
-    def info(self, s, file=sys.stdout):
+    def info(self, s, fp=sys.stdout):
         if self._output_level <= INFO:
-            self.writeline(s, file=file)
+            self.writeline(s, fp=fp)
 
-    def debug(self, s, file=sys.stdout):
+    def debug(self, s, fp=sys.stdout):
         if self._output_level <= DEBUG:
-            self.writeline(s, file=file)
+            self.writeline(s, fp=fp)
 
     def __format(self, s):
         for tag, ccode in TAGS:
diff --git a/src/pylorax/treebuilder.py b/src/pylorax/treebuilder.py
index 2765ba34..79529304 100644
--- a/src/pylorax/treebuilder.py
+++ b/src/pylorax/treebuilder.py
@@ -79,7 +79,7 @@ class RuntimeBuilder(object):
                                basearch=arch.basearch, libdir=arch.libdir)
         self.yum = yum
         self._runner = LoraxTemplateRunner(inroot=root, outroot=root,
-                                           yum=yum, templatedir=templatedir)
+                                           _yum=yum, templatedir=templatedir)
         self.add_templates = add_templates or []
         self.add_template_vars = add_template_vars or {}
         self._installpkgs = installpkgs or []
diff --git a/utils/filediff.py b/utils/filediff.py
index abac28ed..acf1a63d 100644
--- a/utils/filediff.py
+++ b/utils/filediff.py
@@ -21,11 +21,11 @@ def main(args):
 
     # parse sourcedir and targetdir
     sourcetree, targettree = {}, {}
-    for tree, dir in [[sourcetree, sourcedir], [targettree, targetdir]]:
-        for root, _dnames, fnames in os.walk(dir):
+    for tree, dir_name in [[sourcetree, sourcedir], [targettree, targetdir]]:
+        for root, _dnames, fnames in os.walk(dir_name):
             for fname in fnames:
                 fpath = os.path.join(root, fname)
-                rpath = fpath.replace(dir, "", 1)
+                rpath = fpath.replace(dir_name, "", 1)
                 tree[rpath] = fpath
 
     # set up magic