diff --git a/aqt/__init__.py b/aqt/__init__.py
index ea2f4db..c9e659b 100644
--- a/aqt/__init__.py
+++ b/aqt/__init__.py
@@ -29,7 +29,8 @@ from aqt.installer import QtInstaller
 
 
 def main():
-    parser = argparse.ArgumentParser(description='Install Qt SDK.', formatter_class=RawTextHelpFormatter, add_help=True)
+    parser = argparse.ArgumentParser(description='Install Qt SDK.',
+                                     formatter_class=RawTextHelpFormatter, add_help=True)
     parser.add_argument("qt_version", help="Qt version in the format of \"5.X.Y\"")
     parser.add_argument('host', choices=['linux', 'mac', 'windows'], help="host os name")
     parser.add_argument('target', choices=['desktop', 'android', 'ios'], help="target sdk")
@@ -65,4 +66,4 @@ def main():
 
 
 if __name__ == "__main__":
-        sys.exit(main())
+    sys.exit(main())
diff --git a/aqt/archives.py b/aqt/archives.py
index 29f9e8f..c860c71 100644
--- a/aqt/archives.py
+++ b/aqt/archives.py
@@ -94,4 +94,3 @@ class QtArchives:
 
     def get_archives(self):
         return self.archives
-
diff --git a/aqt/installer.py b/aqt/installer.py
index b0d5d18..5b4595e 100644
--- a/aqt/installer.py
+++ b/aqt/installer.py
@@ -47,7 +47,7 @@ class QtInstaller:
         urllib.request.urlretrieve(url, archive)
         sys.stdout.write("\033[K")
         print("-Extracting {}...".format(archive))
-        if platform.system() is 'Windows':
+        if platform.system() == 'Windows':
             subprocess.run([r'C:\Program Files\7-Zip\7z.exe', 'x', '-aoa', '-y', archive])
         else:
             subprocess.run([r'7z', 'x', '-aoa', '-y', archive])
@@ -88,6 +88,5 @@ class QtInstaller:
                     if 'QT_EDITION' in line:
                         line = 'QT_EDITION = OpenSource'
                     f.write(line)
-        except:
+        except IOError:
             pass
-
diff --git a/setup.cfg b/setup.cfg
new file mode 100644
index 0000000..113ca5f
--- /dev/null
+++ b/setup.cfg
@@ -0,0 +1,2 @@
+[flake8]
+max-line-length = 125
diff --git a/setup.py b/setup.py
index f4b6001..1213345 100644
--- a/setup.py
+++ b/setup.py
@@ -5,18 +5,20 @@ import os
 
 from setuptools import setup
 
+
 def readme():
-    with io.open(os.path.join(os.path.dirname(__file__),'README.rst'), mode="r", encoding="UTF-8") as f:
+    with io.open(os.path.join(os.path.dirname(__file__), 'README.rst'), mode="r", encoding="UTF-8") as f:
         return f.read()
 
-setup(name='aqtinstall',
-      version='0.2.0',
-      description='Another Qt installer',
+
+setup(name = 'aqtinstall',
+      version = '0.2.0',
+      description = 'Another Qt installer',
       url='http://github.com/miurahr/qli-installer',
-      license='MIT',
+      license ='MIT',
       long_description=readme(),
-      author='Hioshi Miura',
-      author_email='miurahr@linux.com',
+      author ='Hioshi Miura',
+      author_email ='miurahr@linux.com',
       packages = ["aqt"],
       scripts = ["aqtinst"]
-)
+      )