diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 25d832f..e23e054 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -50,6 +50,6 @@ jobs:
     - name: Lint Python code
       run: |
         eval "$(/home/linuxbrew/.linuxbrew/bin/brew shellenv)"
-        ruff check
+        ruff check --extend-select=C4,C90,PERF,RET,SIM,W
 
     # TODO(eustas): run buildifier
diff --git a/scripts/dictionary/step-02-rfc-to-bin.py b/scripts/dictionary/step-02-rfc-to-bin.py
index ddf255a..3039e27 100644
--- a/scripts/dictionary/step-02-rfc-to-bin.py
+++ b/scripts/dictionary/step-02-rfc-to-bin.py
@@ -18,13 +18,11 @@ for line in lines:
   if appendix_a_found:
     if re_data_line.match(line) is not None:
       data = line.strip()
-      for i in range(32):
-        dictionary.append(int(data[2 * i:2 * i + 2], 16))
+      dictionary.extend(int(data[2 * i:2 * i + 2], 16) for i in range(32))
       if len(dictionary) == 122784:
         break
-  else:
-    if line.startswith("Appendix A."):
-      appendix_a_found = True
+  elif line.startswith("Appendix A."):
+    appendix_a_found = True
 
 bin_path = "dictionary.bin"
 
diff --git a/scripts/dictionary/step-04-generate-java-literals.py b/scripts/dictionary/step-04-generate-java-literals.py
index d864542..c0926ab 100644
--- a/scripts/dictionary/step-04-generate-java-literals.py
+++ b/scripts/dictionary/step-04-generate-java-literals.py
@@ -40,13 +40,12 @@ for b in data:
       is_skip = False
       hi.append(unichr(cntr))
       cntr = skip_flip_offset + 1
+  elif value >= 0x80:
+    cntr += 1
   else:
-    if value >= 0x80:
-      cntr += 1
-    else:
-      is_skip = True
-      hi.append(unichr(cntr))
-      cntr = skip_flip_offset + 1
+    is_skip = True
+    hi.append(unichr(cntr))
+    cntr = skip_flip_offset + 1
 hi.append(unichr(cntr))
 
 low0 = low[0:len(low) // 2]
@@ -56,15 +55,15 @@ low1 = low[len(low) // 2:len(low)]
 def escape(chars):
   result = []
   for c in chars:
-    if "\r" == c:
+    if c == "\r":
       result.append("\\r")
-    elif "\n" == c:
+    elif c == "\n":
       result.append("\\n")
-    elif "\t" == c:
+    elif c == "\t":
       result.append("\\t")
-    elif "\"" == c:
+    elif c == "\"":
       result.append("\\\"")
-    elif "\\" == c:
+    elif c == "\\":
       result.append("\\\\")
     elif ord(c) < 32 or ord(c) >= 127:
       result.append("\\u%04X" % ord(c))
diff --git a/setup.py b/setup.py
index 60cee8a..34017cf 100644
--- a/setup.py
+++ b/setup.py
@@ -53,8 +53,7 @@ def get_version():
 
 def get_test_suite():
     test_loader = unittest.TestLoader()
-    test_suite = test_loader.discover("python", pattern="*_test.py")
-    return test_suite
+    return test_loader.discover("python", pattern="*_test.py")
 
 
 class BuildExt(build_ext):
@@ -77,13 +76,9 @@ class BuildExt(build_ext):
         if not (self.force or dep_util.newer_group(depends, ext_path, "newer")):
             log.debug("skipping '%s' extension (up-to-date)", ext.name)
             return
-        else:
-            log.info("building '%s' extension", ext.name)
+        log.info("building '%s' extension", ext.name)
 
-        c_sources = []
-        for source in ext.sources:
-            if source.endswith(".c"):
-                c_sources.append(source)
+        c_sources = [source for source in ext.sources if source.endswith(".c")]
         extra_args = ext.extra_compile_args or []
 
         objects = []
@@ -184,7 +179,7 @@ USE_SYSTEM_BROTLI = bool_from_environ("USE_SYSTEM_BROTLI")
 
 if USE_SYSTEM_BROTLI:
     import pkgconfig
-    
+
     REQUIRED_BROTLI_SYSTEM_LIBRARIES = ["libbrotlicommon", "libbrotlienc", "libbrotlidec"]
 
     define_macros = []