diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
index 8bb6316061..0e13e82989 100644
--- a/scripts/qapi/commands.py
+++ b/scripts/qapi/commands.py
@@ -274,7 +274,7 @@ class QAPISchemaGenCommandVisitor(QAPISchemaModularCVisitor):
 
 void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds);
 ''',
-                       c_prefix=c_name(self._prefix, protect=False)))
+                             c_prefix=c_name(self._prefix, protect=False)))
         self._genc.preamble_add(mcgen('''
 #include "qemu/osdep.h"
 #include "%(prefix)sqapi-commands.h"
diff --git a/scripts/qapi/expr.py b/scripts/qapi/expr.py
index d7a289eded..fecf466fa7 100644
--- a/scripts/qapi/expr.py
+++ b/scripts/qapi/expr.py
@@ -35,7 +35,6 @@ def check_name_is_str(name, info, source):
 def check_name_str(name, info, source,
                    allow_optional=False, enum_member=False,
                    permit_upper=False):
-    global valid_name
     membername = name
 
     if allow_optional and name.startswith('*'):
@@ -249,7 +248,7 @@ def check_union(expr, info):
 def check_alternate(expr, info):
     members = expr['data']
 
-    if len(members) == 0:
+    if not members:
         raise QAPISemError(info, "'data' must not be empty")
     for (key, value) in members.items():
         source = "'data' member '%s'" % key
diff --git a/scripts/qapi/gen.py b/scripts/qapi/gen.py
index e17354392b..33690bfa3b 100644
--- a/scripts/qapi/gen.py
+++ b/scripts/qapi/gen.py
@@ -45,10 +45,10 @@ class QAPIGen:
 
     def write(self, output_dir):
         pathname = os.path.join(output_dir, self.fname)
-        dir = os.path.dirname(pathname)
-        if dir:
+        odir = os.path.dirname(pathname)
+        if odir:
             try:
-                os.makedirs(dir)
+                os.makedirs(odir)
             except os.error as e:
                 if e.errno != errno.EEXIST:
                     raise
@@ -261,6 +261,9 @@ class QAPISchemaModularCVisitor(QAPISchemaVisitor):
             genc.write(output_dir)
             genh.write(output_dir)
 
+    def _begin_system_module(self, name):
+        pass
+
     def _begin_user_module(self, name):
         pass
 
diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py
index 0cc655fd9f..b5537eddc0 100644
--- a/scripts/qapi/introspect.py
+++ b/scripts/qapi/introspect.py
@@ -10,8 +10,6 @@ This work is licensed under the terms of the GNU GPL, version 2.
 See the COPYING file in the top-level directory.
 """
 
-import string
-
 from qapi.common import *
 from qapi.gen import QAPISchemaMonolithicCVisitor
 from qapi.schema import (QAPISchemaArrayType, QAPISchemaBuiltinType,
diff --git a/scripts/qapi/parser.py b/scripts/qapi/parser.py
index 340f7c4633..abadacbb0e 100644
--- a/scripts/qapi/parser.py
+++ b/scripts/qapi/parser.py
@@ -282,8 +282,7 @@ class QAPISchemaParser:
                 doc.end_comment()
                 self.accept()
                 return doc
-            else:
-                doc.append(self.val)
+            doc.append(self.val)
             self.accept(False)
 
         raise QAPIParseError(self, "documentation comment must end with '##'")
@@ -492,7 +491,7 @@ class QAPIDoc:
             raise QAPIParseError(self._parser,
                                  "'%s' can't follow '%s' section"
                                  % (name, self.sections[0].name))
-        elif self._is_section_tag(name):
+        if self._is_section_tag(name):
             line = line[len(name)+1:]
             self._start_section(name[:-1])
 
@@ -556,7 +555,6 @@ class QAPIDoc:
             raise QAPISemError(feature.info,
                                "feature '%s' lacks documentation"
                                % feature.name)
-            self.features[feature.name] = QAPIDoc.ArgSection(feature.name)
         self.features[feature.name].connect(feature)
 
     def check_expr(self, expr):
diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
index 87837e224e..d759308b4e 100644
--- a/scripts/qapi/schema.py
+++ b/scripts/qapi/schema.py
@@ -19,7 +19,7 @@ import re
 from collections import OrderedDict
 
 from qapi.common import c_name, pointer_suffix
-from qapi.error import QAPIError, QAPIParseError, QAPISemError
+from qapi.error import QAPIError, QAPISemError
 from qapi.expr import check_exprs
 from qapi.parser import QAPISchemaParser
 
@@ -96,14 +96,14 @@ class QAPISchemaVisitor:
     def visit_end(self):
         pass
 
-    def visit_module(self, fname):
+    def visit_module(self, name):
         pass
 
     def visit_needed(self, entity):
         # Default to visiting everything
         return True
 
-    def visit_include(self, fname, info):
+    def visit_include(self, name, info):
         pass
 
     def visit_builtin_type(self, name, info, json_type):
@@ -576,7 +576,7 @@ class QAPISchemaObjectTypeVariants:
             assert self.tag_member.ifcond == []
         if self._tag_name:    # flat union
             # branches that are not explicitly covered get an empty type
-            cases = set([v.name for v in self.variants])
+            cases = {v.name for v in self.variants}
             for m in self.tag_member.type.members:
                 if m.name not in cases:
                     v = QAPISchemaObjectTypeVariant(m.name, self.info,
@@ -848,7 +848,7 @@ class QAPISchema:
 
     def _make_module(self, fname):
         name = self._module_name(fname)
-        if not name in self._module_dict:
+        if name not in self._module_dict:
             self._module_dict[name] = QAPISchemaModule(name)
         return self._module_dict[name]
 
@@ -1097,7 +1097,6 @@ class QAPISchema:
 
     def visit(self, visitor):
         visitor.visit_begin(self)
-        module = None
         for mod in self._module_dict.values():
             mod.visit(visitor)
         visitor.visit_end()