Backport Bitcoin #11881: Remove Python2 support (#2224)

* Merge #11881: Remove Python2 support 1874058 Make base58 python contrib code work with python3 (Evan Klitzke) bc6fdf2 Change all python files to use Python3 (John Newbery) Pull request description: Following discussion here: https://github.com/bitcoin/bitcoin/pull/11843#issuecomment-351033742 It's easier for maintainers if all python tools/scripts support only a single version of Python. There are only a few scripts that aren't explicitly python3 at this point, so this PR changes those remaining scripts to explicitly require python3. Tree-SHA512: 5d38eef6e0fc7d8515e23a1f4c75e8b4160fd0fe23cba52a1f41689b114e54a9e503e0724829e8b41982ef98f2d113df80d9e238213b74f09ceaed0344a19e24 * Merge #12829: Python3 fixup f50975b [contrib] fixup symbol-check.py Python3 support (John Newbery) 5de2b18 [contrib] fixup security-check.py Python3 support (John Newbery) Pull request description: security-check.py and symbol-check.py were broken by #11881. Fix them. Tree-SHA512: 86de3d6dc3292b1ae4cc04c2d7d7dbbf39c9270551d7b224b8d8b19e3184c30c897dbf823200403706d06bb405c0decad5cfd690cb2c0312992a235a4ffcf6bf
2024-12-24 11:32:46 +01:00 · 2018-08-13 18:07:52 +02:00 · 2018-08-13 18:07:52 +02:00 · 7cf9572c26
commit 7cf9572c26
parent 4d3518fe04
13 changed files with 135 additions and 142 deletions
--- a/contrib/devtools/check-doc.py
+++ b/contrib/devtools/check-doc.py
@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (c) 2015 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
@ -15,29 +15,29 @@ import re

 FOLDER_GREP = 'src'
 FOLDER_TEST = 'src/test/'
-CMD_ROOT_DIR = '`git rev-parse --show-toplevel`/%s' % FOLDER_GREP
-CMD_GREP_ARGS = r"egrep -r -I '(map(Multi)?Args(\.count\(|\[)|Get(Bool)?Arg\()\"\-[^\"]+?\"' %s | grep -v '%s'" % (CMD_ROOT_DIR, FOLDER_TEST)
-CMD_GREP_DOCS = r"egrep -r -I 'HelpMessageOpt\(\"\-[^\"=]+?(=|\")' %s" % (CMD_ROOT_DIR)
+CMD_ROOT_DIR = '`git rev-parse --show-toplevel`/{}'.format(FOLDER_GREP)
+CMD_GREP_ARGS = r"egrep -r -I '(map(Multi)?Args(\.count\(|\[)|Get(Bool)?Arg\()\"\-[^\"]+?\"' {} | grep -v '{}'".format(CMD_ROOT_DIR, FOLDER_TEST)
+CMD_GREP_DOCS = r"egrep -r -I 'HelpMessageOpt\(\"\-[^\"=]+?(=|\")' {}".format(CMD_ROOT_DIR)
 REGEX_ARG = re.compile(r'(?:map(?:Multi)?Args(?:\.count\(|\[)|Get(?:Bool)?Arg\()\"(\-[^\"]+?)\"')
 REGEX_DOC = re.compile(r'HelpMessageOpt\(\"(\-[^\"=]+?)(?:=|\")')
 # list unsupported, deprecated and duplicate args as they need no documentation
 SET_DOC_OPTIONAL = set(['-rpcssl', '-benchmark', '-h', '-help', '-socks', '-tor', '-debugnet', '-whitelistalwaysrelay', '-blockminsize'])

 def main():
-  used = check_output(CMD_GREP_ARGS, shell=True)
-  docd = check_output(CMD_GREP_DOCS, shell=True)
+  used = check_output(CMD_GREP_ARGS, shell=True, universal_newlines=True)
+  docd = check_output(CMD_GREP_DOCS, shell=True, universal_newlines=True)

  args_used = set(re.findall(REGEX_ARG,used))
  args_docd = set(re.findall(REGEX_DOC,docd)).union(SET_DOC_OPTIONAL)
  args_need_doc = args_used.difference(args_docd)
  args_unknown = args_docd.difference(args_used)

-  print "Args used        : %s" % len(args_used)
-  print "Args documented  : %s" % len(args_docd)
-  print "Args undocumented: %s" % len(args_need_doc)
-  print args_need_doc
-  print "Args unknown     : %s" % len(args_unknown)
-  print args_unknown
+  print("Args used        : {}".format(len(args_used)))
+  print("Args documented  : {}".format(len(args_docd)))
+  print("Args undocumented: {}".format(len(args_need_doc)))
+  print(args_need_doc)
+  print("Args unknown     : {}".format(len(args_unknown)))
+  print(args_unknown)

  exit(len(args_need_doc))

--- a/contrib/devtools/clang-format-diff.py
+++ b/contrib/devtools/clang-format-diff.py
@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 #===- clang-format-diff.py - ClangFormat Diff Reformatter ----*- python -*--===#
 #
@ -69,10 +69,10 @@ Example usage for git/svn users:

 import argparse
 import difflib
+import io
 import re
 import string
 import subprocess
-import StringIO
 import sys


@ -133,9 +133,9 @@ def main():
          ['-lines', str(start_line) + ':' + str(end_line)])

  # Reformat files containing changes in place.
-  for filename, lines in lines_by_file.iteritems():
+  for filename, lines in lines_by_file.items():
    if args.i and args.verbose:
-      print 'Formatting', filename
+      print('Formatting {}'.format(filename))
    command = [binary, filename]
    if args.i:
      command.append('-i')
@ -143,8 +143,11 @@ def main():
      command.append('-sort-includes')
    command.extend(lines)
    command.extend(['-style=file', '-fallback-style=none'])
-    p = subprocess.Popen(command, stdout=subprocess.PIPE,
-                         stderr=None, stdin=subprocess.PIPE)
+    p = subprocess.Popen(command,
+                         stdout=subprocess.PIPE,
+                         stderr=None,
+                         stdin=subprocess.PIPE,
+                         universal_newlines=True)
    stdout, stderr = p.communicate()
    if p.returncode != 0:
      sys.exit(p.returncode)
@ -152,11 +155,11 @@ def main():
    if not args.i:
      with open(filename) as f:
        code = f.readlines()
-      formatted_code = StringIO.StringIO(stdout).readlines()
+      formatted_code = io.StringIO(stdout).readlines()
      diff = difflib.unified_diff(code, formatted_code,
                                  filename, filename,
                                  '(before formatting)', '(after formatting)')
-      diff_string = string.join(diff, '')
+      diff_string = ''.join(diff)
      if len(diff_string) > 0:
        sys.stdout.write(diff_string)

--- 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) 2014-2015 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", "src/qt/res/icons/crownium", "src/qt/res/icons/drkblue", "src/qt/res/icons/light", "src/qt/res/icons/light-retro", "src/qt/res/icons/trad", "src/qt/res/images", "src/qt/res/images/crownium", "src/qt/res/images/drkblue", "src/qt/res/images/light", "src/qt/res/images/light-retro", "src/qt/res/images/trad", "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")
--- a/contrib/devtools/security-check.py
+++ b/contrib/devtools/security-check.py
@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (c) 2015-2016 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
@ -8,7 +8,6 @@ Exit status will be 0 if successful, and the program will be silent.
 Otherwise the exit status will be 1 and it will log which executables failed which checks.
 Needs `readelf` (for ELF) and `objdump` (for PE).
 '''
-from __future__ import division,print_function,unicode_literals
 import subprocess
 import sys
 import os
@ -21,38 +20,38 @@ def check_ELF_PIE(executable):
    '''
    Check for position independent executable (PIE), allowing for address space randomization.
    '''
-    p = subprocess.Popen([READELF_CMD, '-h', '-W', executable], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
+    p = subprocess.Popen([READELF_CMD, '-h', '-W', executable], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE, universal_newlines=True)
    (stdout, stderr) = p.communicate()
    if p.returncode:
        raise IOError('Error opening file')

    ok = False
-    for line in stdout.split(b'\n'):
+    for line in stdout.splitlines():
        line = line.split()
-        if len(line)>=2 and line[0] == b'Type:' and line[1] == b'DYN':
+        if len(line)>=2 and line[0] == 'Type:' and line[1] == 'DYN':
            ok = True
    return ok

 def get_ELF_program_headers(executable):
    '''Return type and flags for ELF program headers'''
-    p = subprocess.Popen([READELF_CMD, '-l', '-W', executable], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
+    p = subprocess.Popen([READELF_CMD, '-l', '-W', executable], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE, universal_newlines=True)
    (stdout, stderr) = p.communicate()
    if p.returncode:
        raise IOError('Error opening file')
    in_headers = False
    count = 0
    headers = []
-    for line in stdout.split(b'\n'):
-        if line.startswith(b'Program Headers:'):
+    for line in stdout.splitlines():
+        if line.startswith('Program Headers:'):
            in_headers = True
-        if line == b'':
+        if line == '':
            in_headers = False
        if in_headers:
            if count == 1: # header line
-                ofs_typ = line.find(b'Type')
-                ofs_offset = line.find(b'Offset')
-                ofs_flags = line.find(b'Flg')
-                ofs_align = line.find(b'Align')
+                ofs_typ = line.find('Type')
+                ofs_offset = line.find('Offset')
+                ofs_flags = line.find('Flg')
+                ofs_align = line.find('Align')
                if ofs_typ == -1 or ofs_offset == -1 or ofs_flags == -1 or ofs_align  == -1:
                    raise ValueError('Cannot parse elfread -lW output')
            elif count > 1:
@ -69,9 +68,9 @@ def check_ELF_NX(executable):
    have_wx = False
    have_gnu_stack = False
    for (typ, flags) in get_ELF_program_headers(executable):
-        if typ == b'GNU_STACK':
+        if typ == 'GNU_STACK':
            have_gnu_stack = True
-        if b'W' in flags and b'E' in flags: # section is both writable and executable
+        if 'W' in flags and 'E' in flags: # section is both writable and executable
            have_wx = True
    return have_gnu_stack and not have_wx

@ -88,17 +87,17 @@ def check_ELF_RELRO(executable):
        # However, the dynamic linker need to write to this area so these are RW.
        # Glibc itself takes care of mprotecting this area R after relocations are finished.
        # See also http://permalink.gmane.org/gmane.comp.gnu.binutils/71347
-        if typ == b'GNU_RELRO':
+        if typ == 'GNU_RELRO':
            have_gnu_relro = True

    have_bindnow = False
-    p = subprocess.Popen([READELF_CMD, '-d', '-W', executable], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
+    p = subprocess.Popen([READELF_CMD, '-d', '-W', executable], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE, universal_newlines=True)
    (stdout, stderr) = p.communicate()
    if p.returncode:
        raise IOError('Error opening file')
-    for line in stdout.split(b'\n'):
+    for line in stdout.splitlines():
        tokens = line.split()
-        if len(tokens)>1 and tokens[1] == b'(BIND_NOW)' or (len(tokens)>2 and tokens[1] == b'(FLAGS)' and b'BIND_NOW' in tokens[2]):
+        if len(tokens)>1 and tokens[1] == '(BIND_NOW)' or (len(tokens)>2 and tokens[1] == '(FLAGS)' and 'BIND_NOW' in tokens[2]):
            have_bindnow = True
    return have_gnu_relro and have_bindnow

@ -106,13 +105,13 @@ def check_ELF_Canary(executable):
    '''
    Check for use of stack canary
    '''
-    p = subprocess.Popen([READELF_CMD, '--dyn-syms', '-W', executable], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
+    p = subprocess.Popen([READELF_CMD, '--dyn-syms', '-W', executable], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE, universal_newlines=True)
    (stdout, stderr) = p.communicate()
    if p.returncode:
        raise IOError('Error opening file')
    ok = False
-    for line in stdout.split(b'\n'):
-        if b'__stack_chk_fail' in line:
+    for line in stdout.splitlines():
+        if '__stack_chk_fail' in line:
            ok = True
    return ok

@ -122,13 +121,13 @@ def get_PE_dll_characteristics(executable):
    Returns a tuple (arch,bits) where arch is 'i386:x86-64' or 'i386'
    and bits is the DllCharacteristics value.
    '''
-    p = subprocess.Popen([OBJDUMP_CMD, '-x',  executable], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
+    p = subprocess.Popen([OBJDUMP_CMD, '-x',  executable], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE, universal_newlines=True)
    (stdout, stderr) = p.communicate()
    if p.returncode:
        raise IOError('Error opening file')
    arch = ''
    bits = 0
-    for line in stdout.split('\n'):
+    for line in stdout.splitlines():
        tokens = line.split()
        if len(tokens)>=2 and tokens[0] == 'architecture:':
            arch = tokens[1].rstrip(',')
--- a/contrib/devtools/symbol-check.py
+++ b/contrib/devtools/symbol-check.py
@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (c) 2014 Wladimir J. van der Laan
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
@ -11,7 +11,6 @@ Example usage:

    find ../gitian-builder/build -type f -executable | xargs python contrib/devtools/symbol-check.py
 '''
-from __future__ import division, print_function, unicode_literals
 import subprocess
 import re
 import sys
@ -47,28 +46,28 @@ MAX_VERSIONS = {

 # Ignore symbols that are exported as part of every executable
 IGNORE_EXPORTS = {
-b'_edata', b'_end', b'_init', b'__bss_start', b'_fini', b'_IO_stdin_used'
+'_edata', '_end', '_init', '__bss_start', '_fini', '_IO_stdin_used'
 }
 READELF_CMD = os.getenv('READELF', '/usr/bin/readelf')
 CPPFILT_CMD = os.getenv('CPPFILT', '/usr/bin/c++filt')
 # Allowed NEEDED libraries
 ALLOWED_LIBRARIES = {
 # bitcoind and bitcoin-qt
-b'libgcc_s.so.1', # GCC base support
-b'libc.so.6', # C library
-b'libpthread.so.0', # threading
-b'libanl.so.1', # DNS resolve
-b'libm.so.6', # math library
-b'librt.so.1', # real-time (clock)
-b'ld-linux-x86-64.so.2', # 64-bit dynamic linker
-b'ld-linux.so.2', # 32-bit dynamic linker
+'libgcc_s.so.1', # GCC base support
+'libc.so.6', # C library
+'libpthread.so.0', # threading
+'libanl.so.1', # DNS resolve
+'libm.so.6', # math library
+'librt.so.1', # real-time (clock)
+'ld-linux-x86-64.so.2', # 64-bit dynamic linker
+'ld-linux.so.2', # 32-bit dynamic linker
 # bitcoin-qt only
-b'libX11-xcb.so.1', # part of X11
-b'libX11.so.6', # part of X11
-b'libxcb.so.1', # part of X11
-b'libfontconfig.so.1', # font support
-b'libfreetype.so.6', # font parsing
-b'libdl.so.2' # programming interface to dynamic linker
+'libX11-xcb.so.1', # part of X11
+'libX11.so.6', # part of X11
+'libxcb.so.1', # part of X11
+'libfontconfig.so.1', # font support
+'libfreetype.so.6', # font parsing
+'libdl.so.2' # programming interface to dynamic linker
 }

 class CPPFilt(object):
@ -78,10 +77,10 @@ class CPPFilt(object):
    Use a pipe to the 'c++filt' command.
    '''
    def __init__(self):
-        self.proc = subprocess.Popen(CPPFILT_CMD, stdin=subprocess.PIPE, stdout=subprocess.PIPE)
+        self.proc = subprocess.Popen(CPPFILT_CMD, stdin=subprocess.PIPE, stdout=subprocess.PIPE, universal_newlines=True)

    def __call__(self, mangled):
-        self.proc.stdin.write(mangled + b'\n')
+        self.proc.stdin.write(mangled + '\n')
        self.proc.stdin.flush()
        return self.proc.stdout.readline().rstrip()

@ -95,43 +94,43 @@ def read_symbols(executable, imports=True):
    Parse an ELF executable and return a list of (symbol,version) tuples
    for dynamic, imported symbols.
    '''
-    p = subprocess.Popen([READELF_CMD, '--dyn-syms', '-W', executable], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
+    p = subprocess.Popen([READELF_CMD, '--dyn-syms', '-W', executable], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE, universal_newlines=True)
    (stdout, stderr) = p.communicate()
    if p.returncode:
        raise IOError('Could not read symbols for %s: %s' % (executable, stderr.strip()))
    syms = []
-    for line in stdout.split(b'\n'):
+    for line in stdout.splitlines():
        line = line.split()
-        if len(line)>7 and re.match(b'[0-9]+:$', line[0]):
-            (sym, _, version) = line[7].partition(b'@')
-            is_import = line[6] == b'UND'
-            if version.startswith(b'@'):
+        if len(line)>7 and re.match('[0-9]+:$', line[0]):
+            (sym, _, version) = line[7].partition('@')
+            is_import = line[6] == 'UND'
+            if version.startswith('@'):
                version = version[1:]
            if is_import == imports:
                syms.append((sym, version))
    return syms

 def check_version(max_versions, version):
-    if b'_' in version:
-        (lib, _, ver) = version.rpartition(b'_')
+    if '_' in version:
+        (lib, _, ver) = version.rpartition('_')
    else:
        lib = version
        ver = '0'
-    ver = tuple([int(x) for x in ver.split(b'.')])
+    ver = tuple([int(x) for x in ver.split('.')])
    if not lib in max_versions:
        return False
    return ver <= max_versions[lib]

 def read_libraries(filename):
-    p = subprocess.Popen([READELF_CMD, '-d', '-W', filename], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
+    p = subprocess.Popen([READELF_CMD, '-d', '-W', filename], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE, universal_newlines=True)
    (stdout, stderr) = p.communicate()
    if p.returncode:
        raise IOError('Error opening file')
    libraries = []
-    for line in stdout.split(b'\n'):
+    for line in stdout.splitlines():
        tokens = line.split()
-        if len(tokens)>2 and tokens[1] == b'(NEEDED)':
-            match = re.match(b'^Shared library: \[(.*)\]$', b' '.join(tokens[2:]))
+        if len(tokens)>2 and tokens[1] == '(NEEDED)':
+            match = re.match('^Shared library: \[(.*)\]$', ' '.join(tokens[2:]))
            if match:
                libraries.append(match.group(1))
            else:
@ -145,18 +144,18 @@ if __name__ == '__main__':
        # Check imported symbols
        for sym,version in read_symbols(filename, True):
            if version and not check_version(MAX_VERSIONS, version):
-                print('%s: symbol %s from unsupported version %s' % (filename, cppfilt(sym).decode('utf-8'), version.decode('utf-8')))
+                print('%s: symbol %s from unsupported version %s' % (filename, cppfilt(sym), version))
                retval = 1
        # Check exported symbols
        for sym,version in read_symbols(filename, False):
            if sym in IGNORE_EXPORTS:
                continue
-            print('%s: export of symbol %s not allowed' % (filename, cppfilt(sym).decode('utf-8')))
+            print('%s: export of symbol %s not allowed' % (filename, cppfilt(sym)))
            retval = 1
        # Check dependency libraries
        for library_name in read_libraries(filename):
            if library_name not in ALLOWED_LIBRARIES:
-                print('%s: NEEDED library %s is not allowed' % (filename, library_name.decode('utf-8')))
+                print('%s: NEEDED library %s is not allowed' % (filename, library_name))
                retval = 1

    exit(retval)
--- a/contrib/devtools/update-translations.py
+++ b/contrib/devtools/update-translations.py
@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (c) 2014 Wladimir J. van der Laan
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
@ -15,7 +15,6 @@ It will do the following automatically:
 TODO:
 - auto-add new translations to the build system according to the translation process
 '''
-from __future__ import division, print_function
 import subprocess
 import re
 import sys
--- a/contrib/macdeploy/custom_dsstore.py
+++ b/contrib/macdeploy/custom_dsstore.py
@ -1,8 +1,7 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (c) 2013-2015 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
-from __future__ import division,print_function,unicode_literals
 import biplist
 from ds_store import DSStore
 from mac_alias import Alias
--- a/contrib/macdeploy/macdeployqtplus
+++ b/contrib/macdeploy/macdeployqtplus
@ -1,5 +1,4 @@
-#!/usr/bin/env python
-from __future__ import division, print_function, unicode_literals
+#!/usr/bin/env python3
 #
 # Copyright (C) 2011  Patrick "p2k" Schneider <me@p2k-network.org>
 #
@ -203,7 +202,7 @@ def getFrameworks(binaryPath, verbose):
    if verbose >= 3:
        print("Inspecting with otool: " + binaryPath)
    otoolbin=os.getenv("OTOOL", "otool")
-    otool = subprocess.Popen([otoolbin, "-L", binaryPath], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    otool = subprocess.Popen([otoolbin, "-L", binaryPath], stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
    o_stdout, o_stderr = otool.communicate()
    if otool.returncode != 0:
        if verbose >= 1:
@ -211,7 +210,7 @@ def getFrameworks(binaryPath, verbose):
            sys.stderr.flush()
            raise RuntimeError("otool failed with return code %d" % otool.returncode)

-    otoolLines = o_stdout.decode().split("\n")
+    otoolLines = o_stdout.split("\n")
    otoolLines.pop(0) # First line is the inspected binary
    if ".framework" in binaryPath or binaryPath.endswith(".dylib"):
        otoolLines.pop(0) # Frameworks and dylibs list themselves as a dependency.
@ -716,22 +715,6 @@ elif config.sign:

 if config.dmg is not None:

-    #Patch in check_output for Python 2.6
-    if "check_output" not in dir( subprocess ):
-        def f(*popenargs, **kwargs):
-            if 'stdout' in kwargs:
-                raise ValueError('stdout argument not allowed, it will be overridden.')
-            process = subprocess.Popen(stdout=subprocess.PIPE, *popenargs, **kwargs)
-            output, unused_err = process.communicate()
-            retcode = process.poll()
-            if retcode:
-                cmd = kwargs.get("args")
-                if cmd is None:
-                    cmd = popenargs[0]
-                raise CalledProcessError(retcode, cmd)
-            return output
-        subprocess.check_output = f
-
    def runHDIUtil(verb, image_basename, **kwargs):
        hdiutil_args = ["hdiutil", verb, image_basename + ".dmg"]
        if "capture_stdout" in kwargs:
@ -749,7 +732,7 @@ if config.dmg is not None:
            if not value is True:
                hdiutil_args.append(str(value))

-        return run(hdiutil_args)
+        return run(hdiutil_args, universal_newlines=True)

    if verbose >= 2:
        if fancy is None:
@ -791,7 +774,7 @@ if config.dmg is not None:
        except subprocess.CalledProcessError as e:
            sys.exit(e.returncode)

-        m = re.search("/Volumes/(.+$)", output.decode())
+        m = re.search("/Volumes/(.+$)", output)
        disk_root = m.group(0)
        disk_name = m.group(1)

--- a/contrib/testgen/base58.py
+++ b/contrib/testgen/base58.py
@ -28,7 +28,9 @@ def b58encode(v):
    """
    long_value = 0
    for (i, c) in enumerate(v[::-1]):
-        long_value += (256**i) * ord(c)
+        if isinstance(c, str):
+            c = ord(c)
+        long_value += (256**i) * c

    result = ''
    while long_value >= __b58base:
@ -41,7 +43,7 @@ def b58encode(v):
    # leading 0-bytes in the input become leading-1s
    nPad = 0
    for c in v:
-        if c == '\0': nPad += 1
+        if c == 0: nPad += 1
        else: break

    return (__b58chars[0]*nPad) + result
@ -50,8 +52,10 @@ def b58decode(v, length = None):
    """ decode v into a string of len bytes
    """
    long_value = 0
-    for (i, c) in enumerate(v[::-1]):
-        long_value += __b58chars.find(c) * (__b58base**i)
+    for i, c in enumerate(v[::-1]):
+        pos = __b58chars.find(c)
+        assert pos != -1
+        long_value += pos * (__b58base**i)

    result = bytes()
    while long_value >= 256:
@ -62,10 +66,12 @@ def b58decode(v, length = None):

    nPad = 0
    for c in v:
-        if c == __b58chars[0]: nPad += 1
-        else: break
+        if c == __b58chars[0]:
+            nPad += 1
+            continue
+        break

-    result = chr(0)*nPad + result
+    result = bytes(nPad) + result
    if length is not None and len(result) != length:
        return None

--- a/contrib/testgen/gen_base58_test_vectors.py
+++ b/contrib/testgen/gen_base58_test_vectors.py
@ -1,11 +1,11 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (c) 2012 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 '''
 Generate valid and invalid base58 address and private key test vectors.

-Usage: 
+Usage:
    gen_base58_test_vectors.py valid 50 > ../../src/test/data/base58_keys_valid.json
    gen_base58_test_vectors.py invalid 50 > ../../src/test/data/base58_keys_invalid.json
 '''
@ -46,8 +46,8 @@ def is_valid(v):
    if result is None:
        return False
    for template in templates:
-        prefix = str(bytearray(template[0]))
-        suffix = str(bytearray(template[2]))
+        prefix = bytearray(template[0])
+        suffix = bytearray(template[2])
        if result.startswith(prefix) and result.endswith(suffix):
            if (len(result) - len(prefix) - len(suffix)) == template[1]:
                return True
@ -57,20 +57,23 @@ def gen_valid_vectors():
    '''Generate valid test vectors'''
    while True:
        for template in templates:
-            prefix = str(bytearray(template[0]))
-            payload = os.urandom(template[1]) 
-            suffix = str(bytearray(template[2]))
+            prefix = bytearray(template[0])
+            payload = bytearray(os.urandom(template[1]))
+            suffix = bytearray(template[2])
            rv = b58encode_chk(prefix + payload + suffix)
            assert is_valid(rv)
-            metadata = dict([(x,y) for (x,y) in zip(metadata_keys,template[3]) if y is not None])
-            yield (rv, b2a_hex(payload), metadata)
+            metadata = {x: y for x, y in zip(metadata_keys,template[3]) if y is not None}
+            hexrepr = b2a_hex(payload)
+            if isinstance(hexrepr, bytes):
+                hexrepr = hexrepr.decode('utf8')
+            yield (rv, hexrepr, metadata)

 def gen_invalid_vector(template, corrupt_prefix, randomize_payload_size, corrupt_suffix):
    '''Generate possibly invalid vector'''
    if corrupt_prefix:
        prefix = os.urandom(1)
    else:
-        prefix = str(bytearray(template[0]))
+        prefix = bytearray(template[0])
    
    if randomize_payload_size:
        payload = os.urandom(max(int(random.expovariate(0.5)), 50))
@ -80,7 +83,7 @@ def gen_invalid_vector(template, corrupt_prefix, randomize_payload_size, corrupt
    if corrupt_suffix:
        suffix = os.urandom(len(template[2]))
    else:
-        suffix = str(bytearray(template[2]))
+        suffix = bytearray(template[2])

    return b58encode_chk(prefix + payload + suffix)

--- a/doc/release-notes.md
+++ b/doc/release-notes.md
@ -86,6 +86,11 @@ See detailed [change log](https://github.com/dashpay/dash/compare/v0.12.3.1...da
 - [`f833e2ed6`](https://github.com/dashpay/dash/commit/f833e2ed6) Bump to 0.12.3.2 (#2173)


+Python Support
+--------------
+
+Support for Python 2 has been discontinued for all test files and tools.
+
 Credits
 =======

--- a/share/qt/extract_strings_qt.py
+++ b/share/qt/extract_strings_qt.py
@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (c) 2012-2016 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
@ -6,7 +6,6 @@
 Extract _("...") strings for translation and convert to Qt stringdefs so that
 they can be picked up by Qt linguist.
 '''
-from __future__ import division,print_function,unicode_literals
 from subprocess import Popen, PIPE
 import operator
 import os
--- a/share/rpcuser/rpcuser.py
+++ b/share/rpcuser/rpcuser.py
@ -1,4 +1,4 @@
-#!/usr/bin/env python2 
+#!/usr/bin/env python3
 # Copyright (c) 2015 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying 
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.