xml2nroff: Fix issues pointed out by flake8.

This patch includes a few minor fixes pointed out by the flake8 tool.
It drops an unused variable and the related imports, adds some blank
lines where the PEP8 formatting standard indicates they should be, and
does a comparison with None as "is None" instead of "== None".

Signed-off-by: Russell Bryant <russell@ovn.org>
Acked-by: Justin Pettit <jpettit@ovn.org>

diff --git a/build-aux/xml2nroff b/build-aux/xml2nroff
index 2c7e9ae..314a5e1 100755 (executable)
--- a/build-aux/xml2nroff
+++ b/build-aux/xml2nroff
@@ -14,9 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from datetime import date
 import getopt
-import os
 import sys
 import xml.dom.minidom
 
@@ -24,6 +22,7 @@ import build.nroff
 
 argv0 = sys.argv[0]
 
+
 def usage():
     print """\
 %(argv0)s: XML to nroff converter
@@ -40,6 +39,7 @@ The following options are also available:
 """ % {'argv0': argv0}
     sys.exit(0)
 
+
 def manpage_to_nroff(xml_file, subst, version=None):
     f = open(xml_file)
     input = []
@@ -48,9 +48,8 @@ def manpage_to_nroff(xml_file, subst, version=None):
             line = line.replace(k, v)
         input += [line]
     doc = xml.dom.minidom.parseString(''.join(input)).documentElement
-    d = date.fromtimestamp(os.stat(xml_file).st_mtime)
 
-    if version == None:
+    if version is None:
         version = "UNKNOWN"
     program = doc.attributes['program'].nodeValue
     title = doc.attributes['title'].nodeValue