Add python3 support

scripts/unpisi

@@ -16,13 +16,14 @@ from zipfile import BadZipfile
 
 from pisi.package import Package
 
+
 def usage(errmsg):
-    print """
+    print("""
     Error: %s
 
     Usage:
       unpisi PiSi_package.pisi [target_dir]
-    """ % (errmsg)
+    """ % (errmsg))
 
     sys.exit(1)
 
@@ -36,8 +37,8 @@ def main():
 
     try:
         package = Package(sys.argv[1])
-    except BadZipfile, e:
-        print e
+    except BadZipfile as e:
+        print(e)
         sys.exit(1)
 
     if not os.path.exists("install"):
@@ -53,10 +54,11 @@ def main():
     package.extract_install(os.path.join(target, 'install'))
 
     # FIXME: There is a Pisi bug, it already creates an install directory even its empty.
-    if os.listdir('install') == []:
+    if not os.listdir('install'):
         os.rmdir('install')
 
     return 0
 
+
 if __name__ == "__main__":
     sys.exit(main())