deploy: Fix various style issues.

Fix various pylint issues and some python3 compatibility.

Change-Id: I2c35ccc5ad2d0902c229f9de57912cf6d5a83ece

5 files changed, 139 insertions, 130 deletions

diff --git a/utils/common/deploy-rbutil.py b/utils/common/deploy-rbutil.py
index 5085f18efb..2cdbdb52b5 100755
--- a/utils/common/deploy-rbutil.py
+++ b/utils/common/deploy-rbutil.py
@@ -22,30 +22,30 @@ deploy.program = "RockboxUtility"
 deploy.project = "rbutil/rbutilqt/rbutilqt.pro"
 deploy.svnserver = "svn://svn.rockbox.org/rockbox/"
 deploy.svnpaths = \
-           [ "rbutil/",
-             "tools/ucl",
-             "tools/rbspeex",
-             "utils/imxtools",
-             "utils/nwztools",
-             "lib/rbcodec/codecs/libspeex",
-             "docs/COPYING",
-             "docs/gpl-2.0.html",
-             "docs/logo/rockbox-clef.svg",
-             "docs/CREDITS",
-             "tools/iriver.c",
-             "tools/Makefile",
-             "tools/mkboot.h",
-             "tools/voicefont.c",
-             "tools/VOICE_PAUSE.wav",
-             "tools/voice-corrections.txt",
-             "tools/wavtrim.h",
-             "tools/iriver.h",
-             "tools/mkboot.c",
-             "tools/telechips.c",
-             "tools/telechips.h",
-             "tools/voicefont.h",
-             "tools/wavtrim.c",
-             "tools/sapi_voice.vbs" ]
+           ["rbutil/",
+            "tools/ucl",
+            "tools/rbspeex",
+            "utils/imxtools",
+            "utils/nwztools",
+            "lib/rbcodec/codecs/libspeex",
+            "docs/COPYING",
+            "docs/gpl-2.0.html",
+            "docs/logo/rockbox-clef.svg",
+            "docs/CREDITS",
+            "tools/iriver.c",
+            "tools/Makefile",
+            "tools/mkboot.h",
+            "tools/voicefont.c",
+            "tools/VOICE_PAUSE.wav",
+            "tools/voice-corrections.txt",
+            "tools/wavtrim.h",
+            "tools/iriver.h",
+            "tools/mkboot.c",
+            "tools/telechips.c",
+            "tools/telechips.h",
+            "tools/voicefont.h",
+            "tools/wavtrim.c",
+            "tools/sapi_voice.vbs"]
 deploy.useupx = False
 deploy.bundlecopy = {
     "icons/rbutilqt.icns" : "Contents/Resources/",
@@ -77,7 +77,7 @@ deploy.make = {
 # all files of the program. Will get put into an archive after building
 # (zip on w32, tar.bz2 on Linux). Does not apply on Mac which uses dmg.
 # progexe will get added automatically.
-deploy.programfiles = [ ]
+deploy.programfiles = list()
 deploy.nsisscript = ""
 
 deploy.deploy()
diff --git a/utils/common/deploy-themeeditor.py b/utils/common/deploy-themeeditor.py
index 8b66e5aef4..0b72d43985 100755
--- a/utils/common/deploy-themeeditor.py
+++ b/utils/common/deploy-themeeditor.py
@@ -22,13 +22,13 @@ deploy.program = "rbthemeeditor"
 deploy.project = "utils/themeeditor/themeeditor.pro"
 deploy.svnserver = "svn://svn.rockbox.org/rockbox/"
 deploy.svnpaths = \
-           [ "utils/themeeditor/",
-             "lib/skin_parser/",
-             "docs/COPYING" ]
+           ["utils/themeeditor/",
+            "lib/skin_parser/",
+            "docs/COPYING"]
 deploy.useupx = False
 deploy.bundlecopy = {
     "resources/windowicon.icns" : "Contents/Resources/",
-    "Info.plist"          : "Contents/"
+    "Info.plist"                : "Contents/"
 }
 deploy.progexe = {
     "win32"    : "release/rbthemeeditor.exe",
@@ -52,7 +52,7 @@ deploy.make = {
 # all files of the program. Will get put into an archive after building
 # (zip on w32, tar.bz2 on Linux). Does not apply on Mac which uses dmg.
 # progexe will get added automatically.
-deploy.programfiles = [ ]
+deploy.programfiles = list()
 deploy.nsisscript = "utils/themeeditor/themeeditor.nsi"
 
 deploy.deploy()
diff --git a/utils/common/deploy.py b/utils/common/deploy.py
index 571424756b..e0bb7029b8 100755
--- a/utils/common/deploy.py
+++ b/utils/common/deploy.py
@@ -43,21 +43,21 @@ import getopt
 import time
 import hashlib
 import tempfile
-import gitscraper
 from datetime import datetime
+import gitscraper
 
 # modules that are not part of python itself.
 cpus = 1
 try:
     import multiprocessing
     cpus = multiprocessing.cpu_count()
-    print "Info: %s cores found." % cpus
+    print("Info: %s cores found." % cpus)
 except ImportError:
-    print "Warning: multiprocessing module not found. Assuming 1 core."
+    print("Warning: multiprocessing module not found. Assuming 1 core.")
 
 # == Global stuff ==
 # DLL files to ignore when searching for required DLL files.
-systemdlls = [
+SYSTEMDLLS = [
         'advapi32.dll',
         'comdlg32.dll',
         'crypt32.dll',
@@ -94,23 +94,23 @@ gitrepo = os.path.abspath(os.path.join(os.path.dirname(__file__), "../.."))
 
 # == Functions ==
 def usage(myself):
-    print "Usage: %s [options]" % myself
-    print "       -q, --qmake=<qmake>   path to qmake"
-    print "       -p, --project=<pro>   path to .pro file for building with local tree"
-    print "       -t, --tag=<tag>       use specified tag from svn"
-    print "       -a, --add=<file>      add file to build folder before building"
-    print "       -s, --source-only     only create source archive"
-    print "       -b, --binary-only     only create binary archive"
+    print("Usage: %s [options]" % myself)
+    print("       -q, --qmake=<qmake>   path to qmake")
+    print("       -p, --project=<pro>   path to .pro file for building with local tree")
+    print("       -t, --tag=<tag>       use specified tag from svn")
+    print("       -a, --add=<file>      add file to build folder before building")
+    print("       -s, --source-only     only create source archive")
+    print("       -b, --binary-only     only create binary archive")
     if nsisscript != "":
-        print "       -n, --makensis=<file> path to makensis for building Windows setup program."
+        print("       -n, --makensis=<file> path to makensis for building Windows setup program.")
     if sys.platform != "darwin":
-        print "       -d, --dynamic         link dynamically instead of static"
+        print("       -d, --dynamic         link dynamically instead of static")
     if sys.platform != "win32":
-        print "       -x, --cross=          prefix to cross compile for win32"
-    print "       -k, --keep-temp       keep temporary folder on build failure"
-    print "       -h, --help            this help"
-    print "  If neither a project file nor tag is specified trunk will get downloaded"
-    print "  from svn."
+        print("       -x, --cross=          prefix to cross compile for win32")
+    print("       -k, --keep-temp       keep temporary folder on build failure")
+    print("       -h, --help            this help")
+    print("  If neither a project file nor tag is specified trunk will get downloaded")
+    print("  from svn.")
 
 
 def which(executable):
@@ -119,7 +119,7 @@ def which(executable):
         fullpath = p + "/" + executable
         if os.path.exists(fullpath):
             return fullpath
-    print "which: could not find " + executable
+    print("which: could not find " + executable)
     return ""
 
 
@@ -152,7 +152,7 @@ def findversion(versionfile):
 
 def findqt(cross=""):
     '''Search for Qt4 installation. Return path to qmake.'''
-    print "Searching for Qt"
+    print("Searching for Qt")
     bins = [cross + "qmake", cross + "qmake-qt4"]
     for binary in bins:
         try:
@@ -162,7 +162,7 @@ def findqt(cross=""):
                 if not result == "":
                     return result
         except:
-            print sys.exc_value
+            print(sys.exc_value)
 
     return ""
 
@@ -172,27 +172,27 @@ def checkqt(qmakebin):
     result = ""
     # check if binary exists
     if not os.path.exists(qmakebin):
-        print "Specified qmake path does not exist!"
+        print("Specified qmake path does not exist!")
         return result
     # check version
-    output = subprocess.Popen([qmakebin, "-version"], stdout=subprocess.PIPE,
-            stderr=subprocess.PIPE)
+    output = subprocess.Popen(
+        [qmakebin, "-version"], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
     cmdout = output.communicate()
     # don't check the qmake return code here, Qt3 doesn't return 0 on -version.
     for ou in cmdout:
         r = re.compile("Qt[^0-9]+([0-9\.]+[a-z]*)")
         m = re.search(r, ou)
         if not m == None:
-            print "Qt found: %s" % m.group(1)
+            print("Qt found: %s" % m.group(1))
             s = re.compile("[45]\..*")
             n = re.search(s, m.group(1))
-            if not n == None:
+            if n is not None:
                 result = qmakebin
     return result
 
 
 def qmake(qmake, projfile, platform=sys.platform, wd=".", static=True, cross=""):
-    print "Running qmake in %s..." % wd
+    print("Running qmake in %s..." % wd)
     command = [qmake, "-config", "release", "-config", "noccache"]
     if static == True:
         command.extend(["-config", "-static"])
@@ -206,14 +206,14 @@ def qmake(qmake, projfile, platform=sys.platform, wd=".", static=True, cross="")
     output = subprocess.Popen(command, stdout=subprocess.PIPE, cwd=wd)
     output.communicate()
     if not output.returncode == 0:
-        print "qmake returned an error!"
+        print("qmake returned an error!")
         return -1
     return 0
 
 
 def build(wd=".", platform=sys.platform, cross=""):
     # make
-    print "Building ..."
+    print("Building ...")
     # use the current platforms make here, cross compiling uses the native make.
     command = [make[sys.platform]]
     if cpus > 1:
@@ -228,36 +228,36 @@ def build(wd=".", platform=sys.platform, cross=""):
             sys.stdout.write("\n")
             sys.stdout.flush()
             if not output.returncode == 0:
-                print "Build failed!"
+                print("Build failed!")
                 return -1
             break
     if platform != "darwin":
         # strip. OS X handles this via macdeployqt.
-        print "Stripping binary."
+        print("Stripping binary.")
         output = subprocess.Popen([cross + "strip", progexe[platform]], \
                                   stdout=subprocess.PIPE, cwd=wd)
         output.communicate()
         if not output.returncode == 0:
-            print "Stripping failed!"
+            print("Stripping failed!")
             return -1
     return 0
 
 
 def upxfile(wd=".", platform=sys.platform):
     # run upx on binary
-    print "UPX'ing binary ..."
+    print("UPX'ing binary ...")
     output = subprocess.Popen(["upx", progexe[platform]], \
                               stdout=subprocess.PIPE, cwd=wd)
     output.communicate()
     if not output.returncode == 0:
-        print "UPX'ing failed!"
+        print("UPX'ing failed!")
         return -1
     return 0
 
 
 def runnsis(versionstring, nsis, script, srcfolder):
     # run script through nsis to create installer.
-    print "Running NSIS ..."
+    print("Running NSIS ...")
 
     # Assume the generated installer gets placed in the same folder the nsi
     # script lives in.  This seems to be a valid assumption unless the nsi
@@ -276,7 +276,7 @@ def runnsis(versionstring, nsis, script, srcfolder):
                               stdout=subprocess.PIPE)
     output.communicate()
     if not output.returncode == 0:
-        print "NSIS failed!"
+        print("NSIS failed!")
         return -1
     setupfile = program + "-" + versionstring + "-setup.exe"
     # find output filename in nsis script file
@@ -285,7 +285,7 @@ def runnsis(versionstring, nsis, script, srcfolder):
         if re.match(r'^[^;]*OutFile\s+', line) != None:
             nsissetup = re.sub(r'^[^;]*OutFile\s+"(.+)"', r'\1', line).rstrip()
     if nsissetup == "":
-        print "Could not retrieve output file name!"
+        print("Could not retrieve output file name!")
         return -1
     shutil.copy(srcfolder + "/" + os.path.dirname(script) + "/" + nsissetup, \
                 setupfile)
@@ -330,29 +330,29 @@ def finddlls(program, extrapaths=[], cross=""):
     # find DLLs in extrapaths and PATH environment variable.
     dllpaths = []
     for file in dlls:
-        if file in systemdlls:
-            print "System DLL:  " + file
+        if file in SYSTEMDLLS:
+            print("System DLL:  " + file)
             continue
         dllpath = ""
         for path in extrapaths:
             if os.path.exists(path + "/" + file):
                 dllpath = re.sub(r"\\", r"/", path + "/" + file)
-                print file + ": found at " + dllpath
+                print(file + ": found at " + dllpath)
                 dllpaths.append(dllpath)
                 break
         if dllpath == "":
             try:
                 dllpath = re.sub(r"\\", r"/", which(file))
-                print file + ": found at " + dllpath
+                print(file + ": found at " + dllpath)
                 dllpaths.append(dllpath)
             except:
-                print "MISSING DLL: " + file
+                print("MISSING DLL: " + file)
     return dllpaths
 
 
 def zipball(programfiles, versionstring, buildfolder, platform=sys.platform):
     '''package created binary'''
-    print "Creating binary zipball."
+    print("Creating binary zipball.")
     archivebase = program + "-" + versionstring
     outfolder = buildfolder + "/" + archivebase
     archivename = archivebase + ".zip"
@@ -379,7 +379,7 @@ def zipball(programfiles, versionstring, buildfolder, platform=sys.platform):
 
 def tarball(programfiles, versionstring, buildfolder):
     '''package created binary'''
-    print "Creating binary tarball."
+    print("Creating binary tarball.")
     archivebase = program + "-" + versionstring
     outfolder = buildfolder + "/" + archivebase
     archivename = archivebase + ".tar.bz2"
@@ -404,7 +404,7 @@ def macdeploy(versionstring, buildfolder, platform=sys.platform):
 
     # workaround to Qt issues when building out-of-tree. Copy files into bundle.
     sourcebase = buildfolder + re.sub('[^/]+.pro$', '', project) + "/"
-    print sourcebase
+    print(sourcebase)
     for src in bundlecopy:
         shutil.copy(sourcebase + src, appbundle + "/" + bundlecopy[src])
     # end of Qt workaround
@@ -413,7 +413,7 @@ def macdeploy(versionstring, buildfolder, platform=sys.platform):
                               stdout=subprocess.PIPE, cwd=buildfolder)
     output.communicate()
     if not output.returncode == 0:
-        print "macdeployqt failed!"
+        print("macdeployqt failed!")
         return -1
     # copy dmg to output folder
     shutil.copy(buildfolder + "/" + program + ".dmg", dmgfile)
@@ -440,32 +440,33 @@ def filestats(filename):
     if not os.path.exists(filename):
         return
     st = os.stat(filename)
-    print filename, "\n", "-" * len(filename)
-    print "Size:    %i bytes" % st.st_size
+    print(filename, "\n", "-" * len(filename))
+    print("Size:    %i bytes" % st.st_size)
     h = filehashes(filename)
-    print "md5sum:  %s" % h[0]
-    print "sha1sum: %s" % h[1]
-    print "-" * len(filename), "\n"
+    print("md5sum:  %s" % h[0])
+    print("sha1sum: %s" % h[1])
+    print("-" * len(filename), "\n")
 
 
 def tempclean(workfolder, nopro):
     if nopro == True:
-        print "Cleaning up working folder %s" % workfolder
+        print("Cleaning up working folder %s" % workfolder)
         shutil.rmtree(workfolder)
     else:
-        print "Project file specified or cleanup disabled!"
-        print "Temporary files kept at %s" % workfolder
+        print("Project file specified or cleanup disabled!")
+        print("Temporary files kept at %s" % workfolder)
 
 
 def deploy():
     startup = time.time()
 
     try:
-        opts, args = getopt.getopt(sys.argv[1:], "q:p:t:a:n:sbdkx:i:h",
+        opts, args = getopt.getopt(
+            sys.argv[1:], "q:p:t:a:n:sbdkx:i:h",
             ["qmake=", "project=", "tag=", "add=", "makensis=", "source-only",
              "binary-only", "dynamic", "keep-temp", "cross=", "buildid=", "help"])
-    except getopt.GetoptError, err:
-        print str(err)
+    except getopt.GetoptError as err:
+        print(str(err))
         usage(sys.argv[0])
         sys.exit(1)
     qt = ""
@@ -516,17 +517,17 @@ def deploy():
             sys.exit(0)
 
     if source == False and binary == False:
-        print "Building build neither source nor binary means nothing to do. Exiting."
+        print("Building build neither source nor binary means nothing to do. Exiting.")
         sys.exit(1)
 
-    print "Building " + progexe[platform] + " for " + platform
+    print("Building " + progexe[platform] + " for " + platform)
     # search for qmake
     if qt == "":
         qm = findqt(cross)
     else:
         qm = checkqt(qt)
     if qm == "":
-        print "ERROR: No suitable Qt installation found."
+        print("ERROR: No suitable Qt installation found.")
         sys.exit(1)
 
     # create working folder. Use current directory if -p option used.
@@ -552,7 +553,7 @@ def deploy():
         archivename = program + "-" + str(revision) + versionextra + "-src.tar.bz2"
         ver = str(revision)
         os.mkdir(sourcefolder)
-        print "Version: %s" % revision
+        print("Version: %s" % revision)
     else:
         workfolder = "."
         sourcefolder = "."
@@ -561,12 +562,12 @@ def deploy():
     if proj == "":
         proj = sourcefolder + project
         # get sources and pack source tarball
-        if not getsources(treehash, svnpaths, sourcefolder) == 0:
+        if getsources(treehash, svnpaths, sourcefolder) != 0:
             tempclean(workfolder, cleanup and not keeptemp)
             sys.exit(1)
 
         # replace version strings.
-        print "Updating version information in sources"
+        print("Updating version information in sources")
         for f in regreplace:
             infile = open(sourcefolder + "/" + f, "r")
             incontents = infile.readlines()
@@ -590,7 +591,7 @@ def deploy():
             outfile.close()
 
         if source == True:
-            print "Creating source tarball %s\n" % archivename
+            print("Creating source tarball %s\n" % archivename)
             tf = tarfile.open(archivename, mode='w:bz2')
             tf.add(sourcefolder, os.path.basename(re.subn('/$', '', sourcefolder)[0]))
             tf.close()
@@ -607,7 +608,7 @@ def deploy():
 
     # check project file
     if not os.path.exists(proj):
-        print "ERROR: path to project file wrong."
+        print("ERROR: path to project file wrong.")
         sys.exit(1)
 
     # copy specified (--add) files to working folder
@@ -615,8 +616,8 @@ def deploy():
         shutil.copy(f, sourcefolder)
     buildstart = time.time()
     header = "Building %s %s" % (program, ver)
-    print header
-    print len(header) * "="
+    print(header)
+    print(len(header) * "=")
 
     # build it.
     if not qmake(qm, proj, platform, sourcefolder, static, cross) == 0:
@@ -649,8 +650,8 @@ def deploy():
         if platform == "linux2":
             for p in progfiles:
                 prog = sourcefolder + "/" + p
-                output = subprocess.Popen(["file", prog],
-                        stdout=subprocess.PIPE)
+                output = subprocess.Popen(
+                    ["file", prog], stdout=subprocess.PIPE)
                 res = output.communicate()
                 if re.findall("ELF 64-bit", res[0]):
                     ver += "-64bit"
@@ -663,7 +664,7 @@ def deploy():
 
     # display summary
     headline = "Build Summary for %s" % program
-    print "\n", headline, "\n", "=" * len(headline)
+    print("\n", headline, "\n", "=" * len(headline))
     if not archivename == "":
         filestats(archivename)
     filestats(archive)
@@ -672,10 +673,10 @@ def deploy():
     dursecs = (int)(duration % 60)
     buildmins = (int)(buildtime / 60)
     buildsecs = (int)(buildtime % 60)
-    print "Overall time %smin %ssec, building took %smin %ssec." % \
-        (durmins, dursecs, buildmins, buildsecs)
+    print("Overall time %smin %ssec, building took %smin %ssec." % \
+        (durmins, dursecs, buildmins, buildsecs))
 
 
 if __name__ == "__main__":
-    print "You cannot run this module directly!"
-    print "Set required environment and call deploy()."
+    print("You cannot run this module directly!")
+    print("Set required environment and call deploy().")
diff --git a/utils/common/gitscraper.py b/utils/common/gitscraper.py
index 86d6a980cd..496d32bce3 100755
--- a/utils/common/gitscraper.py
+++ b/utils/common/gitscraper.py
@@ -42,10 +42,11 @@ def get_refs(repo):
     @return Dict matching hashes to each ref.
     '''
     print("Getting list of refs")
-    output = subprocess.Popen(["git", "show-ref", "--abbrev"],
-            stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=repo)
+    output = subprocess.Popen(
+        ["git", "show-ref", "--abbrev"],
+        stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=repo)
     cmdout = output.communicate()
-    refs = {}
+    refs = dict()
 
     if len(cmdout[1]) > 0:
         print("An error occured!\n")
@@ -53,7 +54,7 @@ def get_refs(repo):
         return refs
 
     for line in cmdout:
-        regex = re.findall(b'([a-f0-9]+)\s+(\S+)', line)
+        regex = re.findall(b'([a-f0-9]+)\\s+(\\S+)', line)
         for r in regex:
             # ref is the key, hash its value.
             refs[r[1].decode()] = r[0].decode()
@@ -61,7 +62,7 @@ def get_refs(repo):
     return refs
 
 
-def get_lstree(repo, start, filterlist=[]):
+def get_lstree(repo, start, filterlist=None):
     '''Get recursive list of tree objects for a given tree.
     @param repo Path to repository root.
     @param start Hash identifying the tree.
@@ -69,10 +70,13 @@ def get_lstree(repo, start, filterlist=[]):
                       An empty list will retrieve all paths.
     @return Dict mapping filename to blob hash
     '''
-    output = subprocess.Popen(["git", "ls-tree", "-r", start],
-            stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=repo)
+    if filterlist is None:
+        filterlist = list()
+    output = subprocess.Popen(
+        ["git", "ls-tree", "-r", start],
+        stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=repo)
     cmdout = output.communicate()
-    objects = {}
+    objects = dict()
 
     if len(cmdout[1]) > 0:
         print("An error occured!\n")
@@ -80,8 +84,8 @@ def get_lstree(repo, start, filterlist=[]):
         return objects
 
     for line in cmdout[0].decode().split('\n'):
-        regex = re.findall(b'([0-9]+)\s+([a-z]+)\s+([0-9a-f]+)\s+(.*)',
-                line.encode())
+        regex = re.findall(b'([0-9]+)\\s+([a-z]+)\\s+([0-9a-f]+)\\s+(.*)',
+                           line.encode())
         for rf in regex:
             # filter
             add = False
@@ -107,8 +111,8 @@ def get_file_timestamp(repo, tree, filename):
     @return Timestamp as string.
     '''
     output = subprocess.Popen(
-            ["git", "log", "--format=%ai", "-n", "1", tree, filename],
-            stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=repo)
+        ["git", "log", "--format=%ai", "-n", "1", tree, filename],
+        stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=repo)
     cmdout = output.communicate()
 
     return cmdout[0].decode().rstrip()
@@ -121,8 +125,9 @@ def get_object(repo, blob, destfile):
     @param destfile filename for blob output.
     @return True if file was successfully written, False on error.
     '''
-    output = subprocess.Popen(["git", "cat-file", "-p", blob],
-            stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=repo)
+    output = subprocess.Popen(
+        ["git", "cat-file", "-p", blob],
+        stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=repo)
     cmdout = output.communicate()
     # make sure output path exists
     if len(cmdout[1]) > 0:
@@ -143,8 +148,9 @@ def describe_treehash(repo, treehash):
     @param treehash Hash identifying the tree / commit to describe.
     @return Description string.
     '''
-    output = subprocess.Popen(["git", "describe", treehash],
-            stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=repo)
+    output = subprocess.Popen(
+        ["git", "describe", treehash],
+        stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=repo)
     cmdout = output.communicate()
     if len(cmdout[1]) > 0:
         print("An error occured!\n")
@@ -153,7 +159,7 @@ def describe_treehash(repo, treehash):
     return cmdout[0].rstrip()
 
 
-def scrape_files(repo, treehash, filelist, dest="", timestamp_files=[]):
+def scrape_files(repo, treehash, filelist, dest=None, timestamp_files=None):
     '''Scrape list of files from repository.
     @param repo Path to repository root.
     @param treehash Hash identifying the tree.
@@ -167,7 +173,9 @@ def scrape_files(repo, treehash, filelist, dest="", timestamp_files=[]):
     '''
     print("Scraping files from repository")
 
-    if dest == "":
+    if timestamp_files is None:
+        timestamp_files = list()
+    if dest is None:
         dest = tempfile.mkdtemp()
     treeobjects = get_lstree(repo, treehash, filelist)
     timestamps = {}
@@ -180,8 +188,8 @@ def scrape_files(repo, treehash, filelist, dest="", timestamp_files=[]):
     return [dest, timestamps]
 
 
-def archive_files(repo, treehash, filelist, basename, tmpfolder="",
-        archive="tbz"):
+def archive_files(repo, treehash, filelist, basename, tmpfolder=None,
+                  archive="tbz"):
     '''Archive list of files into tarball.
     @param repo Path to repository root.
     @param treehash Hash identifying the tree.
@@ -197,20 +205,20 @@ def archive_files(repo, treehash, filelist, basename, tmpfolder="",
     @return Output filename.
     '''
 
-    if tmpfolder == "":
+    if tmpfolder is None:
         temp_remove = True
         tmpfolder = tempfile.mkdtemp()
     else:
         temp_remove = False
-    workfolder = scrape_files(repo, treehash, filelist,
-            os.path.join(tmpfolder, basename))[0]
+    workfolder = scrape_files(
+        repo, treehash, filelist, os.path.join(tmpfolder, basename))[0]
     if basename is "":
         return ""
     print("Archiving files from repository")
     if archive == "7z":
         outfile = basename + ".7z"
-        output = subprocess.Popen(["7z", "a",
-            os.path.join(os.getcwd(), basename + ".7z"), basename],
+        output = subprocess.Popen(
+            ["7z", "a", os.path.join(os.getcwd(), basename + ".7z"), basename],
             cwd=tmpfolder, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
         output.communicate()
     elif archive == "tbz":
diff --git a/utils/common/tarball.py b/utils/common/tarball.py
index 2e32776702..3fda206002 100755
--- a/utils/common/tarball.py
+++ b/utils/common/tarball.py
@@ -1,8 +1,8 @@
 #!/usr/bin/python
 
-import gitscraper
 import os
 import sys
+import gitscraper
 
 if len(sys.argv) < 2:
     print("Usage: %s <version|hash>" % sys.argv[0])