diff --git a/gitc_utils.py b/gitc_utils.py
index b47e181c..8b5b007e 100644
--- a/gitc_utils.py
+++ b/gitc_utils.py
@@ -104,11 +104,11 @@ def generate_gitc_manifest(gitc_manifest, manifest, paths=None):
       if not proj.upstream and not git_config.IsId(proj.revisionExpr):
         proj.upstream = proj.revisionExpr
 
-      if not path in gitc_manifest.paths:
+      if path not in gitc_manifest.paths:
         # Any new projects need their first revision, even if we weren't asked
         # for them.
         projects.append(proj)
-      elif not path in paths:
+      elif path not in paths:
         # And copy revisions from the previous manifest if we're not updating
         # them now.
         gitc_proj = gitc_manifest.paths[path]
diff --git a/manifest_xml.py b/manifest_xml.py
index 2be717e2..d24dbcea 100644
--- a/manifest_xml.py
+++ b/manifest_xml.py
@@ -1093,7 +1093,7 @@ class XmlManifest(object):
     diff = {'added': [], 'removed': [], 'changed': [], 'unreachable': []}
 
     for proj in fromKeys:
-      if not proj in toKeys:
+      if proj not in toKeys:
         diff['removed'].append(fromProjects[proj])
       else:
         fromProj = fromProjects[proj]
diff --git a/subcmds/branches.py b/subcmds/branches.py
index fb60d7de..b8958848 100644
--- a/subcmds/branches.py
+++ b/subcmds/branches.py
@@ -158,7 +158,7 @@ is shown, then the branch appears in all projects.
           for b in i.projects:
             have.add(b.project)
           for p in projects:
-            if not p in have:
+            if p not in have:
               paths.append(p.relpath)
 
         s = ' %s %s' % (in_type, ', '.join(paths))
diff --git a/subcmds/sync.py b/subcmds/sync.py
index 13c419c3..54b5a7fc 100644
--- a/subcmds/sync.py
+++ b/subcmds/sync.py
@@ -744,7 +744,7 @@ later is required to fix a server side protocol bug.
     if not opt.quiet:
       print('Using manifest server %s' % manifest_server)
 
-    if not '@' in manifest_server:
+    if '@' not in manifest_server:
       username = None
       password = None
       if opt.manifest_server_username and opt.manifest_server_password: