diff --git a/Lib/distutils/command/sdist.py b/Lib/distutils/command/sdist.py
index bb2106120ac..f51d72fad75 100644
--- a/Lib/distutils/command/sdist.py
+++ b/Lib/distutils/command/sdist.py
@@ -240,8 +240,7 @@ def add_defaults(self):
         optional = ['test/test*.py', 'setup.cfg']
         for pattern in optional:
             files = filter(os.path.isfile, glob(pattern))
-            if files:
-                self.filelist.extend(files)
+            self.filelist.extend(files)
 
         # build_py is used to get:
         #  - python modules
diff --git a/Lib/http/server.py b/Lib/http/server.py
index d2a685f7974..098ad250cac 100644
--- a/Lib/http/server.py
+++ b/Lib/http/server.py
@@ -1023,8 +1023,9 @@ def run_cgi(self):
         if ua:
             env['HTTP_USER_AGENT'] = ua
         co = filter(None, self.headers.get_all('cookie', []))
-        if co:
-            env['HTTP_COOKIE'] = ', '.join(co)
+        cookie_str = ', '.join(co)
+        if cookie_str:
+            env['HTTP_COOKIE'] = cookie_str
         # XXX Other HTTP_* headers
         # Since we're setting the env in the parent, provide empty
         # values to override previously set values
diff --git a/Lib/platform.py b/Lib/platform.py
index 75f92af0068..f856a43c046 100755
--- a/Lib/platform.py
+++ b/Lib/platform.py
@@ -1137,7 +1137,7 @@ def uname():
     except AttributeError:
         no_os_uname = 1
 
-    if no_os_uname or not filter(None, (system, node, release, version, machine)):
+    if no_os_uname or not list(filter(None, (system, node, release, version, machine))):
         # Hmm, no there is either no uname or uname has returned
         #'unknowns'... we'll have to poke around the system then.
         if no_os_uname: