Change all python files to use Python3

1 files changed, 14 insertions, 16 deletions

diff --git a/contrib/devtools/optimize-pngs.py b/contrib/devtools/optimize-pngs.py
index 5cb3bb6f75..565b199125 100755
--- a/contrib/devtools/optimize-pngs.py
+++ b/contrib/devtools/optimize-pngs.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (c) 2014-2017 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
@@ -10,7 +10,7 @@ import os
 import sys
 import subprocess
 import hashlib
-from PIL import Image
+from PIL import Image  # pip3 install Pillow
 
 def file_hash(filename):
     '''Return hash of raw file contents'''
@@ -27,7 +27,7 @@ def content_hash(filename):
 pngcrush = 'pngcrush'
 git = 'git'
 folders = ["src/qt/res/movies", "src/qt/res/icons", "share/pixmaps"]
-basePath = subprocess.check_output([git, 'rev-parse', '--show-toplevel']).rstrip('\n')
+basePath = subprocess.check_output([git, 'rev-parse', '--show-toplevel'], universal_newlines=True).rstrip('\n')
 totalSaveBytes = 0
 noHashChange = True
 
@@ -37,42 +37,40 @@ for folder in folders:
     for file in os.listdir(absFolder):
         extension = os.path.splitext(file)[1]
         if extension.lower() == '.png':
-            print("optimizing "+file+"..."),
+            print("optimizing {}...".format(file), end =' ')
             file_path = os.path.join(absFolder, file)
             fileMetaMap = {'file' : file, 'osize': os.path.getsize(file_path), 'sha256Old' : file_hash(file_path)}
             fileMetaMap['contentHashPre'] = content_hash(file_path)
         
-            pngCrushOutput = ""
             try:
-                pngCrushOutput = subprocess.check_output(
-                        [pngcrush, "-brute", "-ow", "-rem", "gAMA", "-rem", "cHRM", "-rem", "iCCP", "-rem", "sRGB", "-rem", "alla", "-rem", "text", file_path],
-                        stderr=subprocess.STDOUT).rstrip('\n')
+                subprocess.call([pngcrush, "-brute", "-ow", "-rem", "gAMA", "-rem", "cHRM", "-rem", "iCCP", "-rem", "sRGB", "-rem", "alla", "-rem", "text", file_path],
+                                stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
             except:
-                print "pngcrush is not installed, aborting..."
+                print("pngcrush is not installed, aborting...")
                 sys.exit(0)
         
             #verify
-            if "Not a PNG file" in subprocess.check_output([pngcrush, "-n", "-v", file_path], stderr=subprocess.STDOUT):
-                print "PNG file "+file+" is corrupted after crushing, check out pngcursh version"
+            if "Not a PNG file" in subprocess.check_output([pngcrush, "-n", "-v", file_path], stderr=subprocess.STDOUT, universal_newlines=True):
+                print("PNG file "+file+" is corrupted after crushing, check out pngcursh version")
                 sys.exit(1)
             
             fileMetaMap['sha256New'] = file_hash(file_path)
             fileMetaMap['contentHashPost'] = content_hash(file_path)
 
             if fileMetaMap['contentHashPre'] != fileMetaMap['contentHashPost']:
-                print "Image contents of PNG file "+file+" before and after crushing don't match"
+                print("Image contents of PNG file {} before and after crushing don't match".format(file))
                 sys.exit(1)
 
             fileMetaMap['psize'] = os.path.getsize(file_path)
             outputArray.append(fileMetaMap)
-            print("done\n"),
+            print("done")
 
-print "summary:\n+++++++++++++++++"
+print("summary:\n+++++++++++++++++")
 for fileDict in outputArray:
     oldHash = fileDict['sha256Old']
     newHash = fileDict['sha256New']
     totalSaveBytes += fileDict['osize'] - fileDict['psize']
     noHashChange = noHashChange and (oldHash == newHash)
-    print fileDict['file']+"\n  size diff from: "+str(fileDict['osize'])+" to: "+str(fileDict['psize'])+"\n  old sha256: "+oldHash+"\n  new sha256: "+newHash+"\n"
+    print(fileDict['file']+"\n  size diff from: "+str(fileDict['osize'])+" to: "+str(fileDict['psize'])+"\n  old sha256: "+oldHash+"\n  new sha256: "+newHash+"\n")
     
-print "completed. Checksum stable: "+str(noHashChange)+". Total reduction: "+str(totalSaveBytes)+" bytes"
+print("completed. Checksum stable: "+str(noHashChange)+". Total reduction: "+str(totalSaveBytes)+" bytes")