From 86fcc100ab5c771b41c1b9ac50b7c79b688d0669 Mon Sep 17 00:00:00 2001
From: Justin Turner Arthur <justinarthur@gmail.com>
Date: Thu, 25 Feb 2016 23:57:33 -0600
Subject: [PATCH 01/18] Run of the 2to3 script.

---
 run_electrum_server.py      | 39 ++++++++++++++++++-------------------
 src/__init__.py             | 16 +++++++--------
 src/blockchain_processor.py | 34 ++++++++++++++++----------------
 src/deserialize.py          | 12 ++++++------
 src/ircthread.py            | 12 ++++++------
 src/processor.py            | 12 ++++++------
 src/server_processor.py     | 18 ++++++++---------
 src/storage.py              | 26 ++++++++++++-------------
 src/stratum_tcp.py          | 10 +++++-----
 src/utils.py                |  8 ++++----
 10 files changed, 93 insertions(+), 94 deletions(-)

diff --git a/run_electrum_server.py b/run_electrum_server.py
index dd89c8b6..39b2ea63 100755
--- a/run_electrum_server.py
+++ b/run_electrum_server.py
@@ -22,7 +22,7 @@
 # SOFTWARE.
 
 import argparse
-import ConfigParser
+import configparser
 import logging
 import socket
 import sys
@@ -46,11 +46,11 @@
 logging.basicConfig()
 
 if sys.maxsize <= 2**32:
-    print "Warning: it looks like you are using a 32bit system. You may experience crashes caused by mmap"
+    print("Warning: it looks like you are using a 32bit system. You may experience crashes caused by mmap")
 
 if os.getuid() == 0:
-    print "Do not run this program as root!"
-    print "Run the install script to create a non-privileged user."
+    print("Do not run this program as root!")
+    print("Run the install script to create a non-privileged user.")
     sys.exit()
 
 def attempt_read_config(config, filename):
@@ -82,7 +82,7 @@ def setup_network_params(config):
         storage.GENESIS_HASH = config.get('network', 'genesis_hash')
 
 def create_config(filename=None):
-    config = ConfigParser.ConfigParser()
+    config = configparser.ConfigParser()
     # set some defaults, which will be overwritten by the config file
     config.add_section('server')
     config.set('server', 'banner', 'Welcome to Electrum!')
@@ -123,7 +123,7 @@ def create_config(filename=None):
                 break
 
     if not os.path.isfile(filename):
-        print 'could not find electrum configuration file "%s"' % filename
+        print('could not find electrum configuration file "%s"' % filename)
         sys.exit(1)
 
     attempt_read_config(config, filename)
@@ -135,24 +135,24 @@ def create_config(filename=None):
 
 def run_rpc_command(params, electrum_rpc_port):
     cmd = params[0]
-    import xmlrpclib
-    server = xmlrpclib.ServerProxy('http://localhost:%d' % electrum_rpc_port)
+    import xmlrpc.client
+    server = xmlrpc.client.ServerProxy('http://localhost:%d' % electrum_rpc_port)
     func = getattr(server, cmd)
     r = func(*params[1:])
     if cmd == 'sessions':
         now = time.time()
-        print 'type           address         sub  version  time'
+        print('type           address         sub  version  time')
         for item in r:
-            print '%4s   %21s   %3s  %7s  %.2f' % (item.get('name'),
+            print('%4s   %21s   %3s  %7s  %.2f' % (item.get('name'),
                                                    item.get('address'),
                                                    item.get('subscriptions'),
                                                    item.get('version'),
                                                    (now - item.get('time')),
-                                                   )
+                                                   ))
     elif cmd == 'debug':
-        print r
+        print(r)
     else:
-        print json.dumps(r, indent=4, sort_keys=True)
+        print(json.dumps(r, indent=4, sort_keys=True))
 
 
 def cmd_banner_update():
@@ -169,18 +169,17 @@ def cmd_getinfo():
         }
 
 def cmd_sessions():
-    return map(lambda s: {"time": s.time,
+    return [{"time": s.time,
                           "name": s.name,
                           "address": s.address,
                           "version": s.version,
-                          "subscriptions": len(s.subscriptions)},
-               dispatcher.request_dispatcher.get_sessions())
+                          "subscriptions": len(s.subscriptions)} for s in dispatcher.request_dispatcher.get_sessions()]
 
 def cmd_numsessions():
     return len(dispatcher.request_dispatcher.get_sessions())
 
 def cmd_peers():
-    return server_proc.peers.keys()
+    return list(server_proc.peers.keys())
 
 def cmd_numpeers():
     return len(server_proc.peers)
@@ -290,7 +289,7 @@ def stop_server():
         try:
             run_rpc_command(args.command, electrum_rpc_port)
         except socket.error:
-            print "server not running"
+            print("server not running")
             sys.exit(1)
         sys.exit(0)
 
@@ -301,12 +300,12 @@ def stop_server():
         is_running = False
 
     if is_running:
-        print "server already running"
+        print("server already running")
         sys.exit(1)
 
     start_server(config)
 
-    from SimpleXMLRPCServer import SimpleXMLRPCServer
+    from xmlrpc.server import SimpleXMLRPCServer
     server = SimpleXMLRPCServer(('localhost', electrum_rpc_port), allow_none=True, logRequests=False)
     server.register_function(lambda: os.getpid(), 'getpid')
     server.register_function(shared.stop, 'stop')
diff --git a/src/__init__.py b/src/__init__.py
index 3434f4d6..1a5cb08d 100644
--- a/src/__init__.py
+++ b/src/__init__.py
@@ -1,9 +1,9 @@
-import utils
-import storage
-import deserialize
-import networks
-import blockchain_processor
-import processor
-import version
+from . import utils
+from . import storage
+from . import deserialize
+from . import networks
+from . import blockchain_processor
+from . import processor
+from . import version
 import irc
-import stratum_tcp
+from . import stratum_tcp
diff --git a/src/blockchain_processor.py b/src/blockchain_processor.py
index 7b9cec35..35311d82 100644
--- a/src/blockchain_processor.py
+++ b/src/blockchain_processor.py
@@ -24,17 +24,17 @@
 import hashlib
 from json import dumps, load
 import os
-from Queue import Queue
+from queue import Queue
 import random
 import sys
 import time
 import threading
-import urllib
+import urllib.request, urllib.parse, urllib.error
 
-import deserialize
-from processor import Processor, print_log
-from storage import Storage
-from utils import logger, hash_decode, hash_encode, Hash, header_from_string, header_to_string, ProfiledThread, \
+from . import deserialize
+from .processor import Processor, print_log
+from .storage import Storage
+from .utils import logger, hash_decode, hash_encode, Hash, header_from_string, header_to_string, ProfiledThread, \
     rev_hex, int_to_hex4
 
 class BlockchainProcessor(Processor):
@@ -156,7 +156,7 @@ def bitcoind(self, method, params=()):
         postdata = dumps({"method": method, 'params': params, 'id': 'jsonrpc'})
         while True:
             try:
-                response = urllib.urlopen(self.bitcoind_url, postdata)
+                response = urllib.request.urlopen(self.bitcoind_url, postdata)
                 r = load(response)
                 response.close()
             except:
@@ -355,7 +355,7 @@ def get_merkle(self, tx_hash, height, cache_only):
         tx_list = b.get('tx')
         tx_pos = tx_list.index(tx_hash)
 
-        merkle = map(hash_decode, tx_list)
+        merkle = list(map(hash_decode, tx_list))
         target_hash = hash_decode(tx_hash)
         s = []
         while len(merkle) != 1:
@@ -568,7 +568,7 @@ def process(self, request, cache_only=False):
                 txo = self.bitcoind('sendrawtransaction', params)
                 print_log("sent tx:", txo)
                 result = txo
-            except BaseException, e:
+            except BaseException as e:
                 error = e.args[0]
                 if error["code"] == -26:
                     # If we return anything that's not the transaction hash,
@@ -621,7 +621,7 @@ def get_block(self, block_hash):
 
         while True:
             try:
-                response = urllib.urlopen(self.bitcoind_url, postdata)
+                response = urllib.request.urlopen(self.bitcoind_url, postdata)
                 r = load(response)
                 response.close()
             except:
@@ -667,7 +667,7 @@ def catch_up(self, sync=True):
             self.up_to_date = False
             try:
                 next_block_hash = self.bitcoind('getblockhash', (self.storage.height + 1,))
-            except BaseException, e:
+            except BaseException as e:
                 revert = True
 
             next_block = self.get_block(next_block_hash if not revert else self.storage.last_hash)
@@ -732,7 +732,7 @@ def memorypool_update(self):
         self.mempool_hashes = mempool_hashes
 
         # check all tx outputs
-        for tx_hash, tx in new_tx.iteritems():
+        for tx_hash, tx in new_tx.items():
             mpa = self.mempool_addresses.get(tx_hash, {})
             out_values = []
             out_sum = 0
@@ -754,7 +754,7 @@ def memorypool_update(self):
             self.mempool_unconfirmed[tx_hash] = set()
 
         # check all inputs
-        for tx_hash, tx in new_tx.iteritems():
+        for tx_hash, tx in new_tx.items():
             mpa = self.mempool_addresses.get(tx_hash, {})
             # are we spending unconfirmed inputs?
             input_sum = 0
@@ -785,7 +785,7 @@ def memorypool_update(self):
             self.mempool_fees[tx_hash] += input_sum
 
         # remove deprecated entries from mempool_addresses
-        for tx_hash, addresses in self.mempool_addresses.items():
+        for tx_hash, addresses in list(self.mempool_addresses.items()):
             if tx_hash not in self.mempool_hashes:
                 del self.mempool_addresses[tx_hash]
                 del self.mempool_values[tx_hash]
@@ -795,7 +795,7 @@ def memorypool_update(self):
 
         # remove deprecated entries from mempool_hist
         new_mempool_hist = {}
-        for addr in self.mempool_hist.iterkeys():
+        for addr in self.mempool_hist.keys():
             h = self.mempool_hist[addr]
             hh = []
             for tx_hash, delta in h:
@@ -804,9 +804,9 @@ def memorypool_update(self):
             if hh:
                 new_mempool_hist[addr] = hh
         # add new transactions to mempool_hist
-        for tx_hash in new_tx.iterkeys():
+        for tx_hash in new_tx.keys():
             addresses = self.mempool_addresses[tx_hash]
-            for addr, delta in addresses.iteritems():
+            for addr, delta in addresses.items():
                 h = new_mempool_hist.get(addr, [])
                 if (tx_hash, delta) not in h:
                     h.append((tx_hash, delta))
diff --git a/src/deserialize.py b/src/deserialize.py
index ccc4eaa7..7443f8b1 100644
--- a/src/deserialize.py
+++ b/src/deserialize.py
@@ -7,7 +7,7 @@
 import struct
 import types
 
-from utils import hash_160_to_pubkey_address, hash_160_to_script_address, public_key_to_pubkey_address, hash_encode,\
+from .utils import hash_160_to_pubkey_address, hash_160_to_script_address, public_key_to_pubkey_address, hash_encode,\
     hash_160
 
 
@@ -170,11 +170,11 @@ def __init__(self, name, enumList):
         uniqueNames = []
         uniqueValues = []
         for x in enumList:
-            if isinstance(x, types.TupleType):
+            if isinstance(x, tuple):
                 x, i = x
-            if not isinstance(x, types.StringType):
+            if not isinstance(x, bytes):
                 raise EnumException("enum name is not a string: %r" % x)
-            if not isinstance(i, types.IntType):
+            if not isinstance(i, int):
                 raise EnumException("enum value is not an integer: %r" % i)
             if x in uniqueNames:
                 raise EnumException("enum name is not unique: %r" % x)
@@ -235,13 +235,13 @@ def parse_Transaction(vds, is_coinbase):
     d['version'] = vds.read_int32()
     n_vin = vds.read_compact_size()
     d['inputs'] = []
-    for i in xrange(n_vin):
+    for i in range(n_vin):
         o = parse_TxIn(vds)
         if not is_coinbase:
             d['inputs'].append(o)
     n_vout = vds.read_compact_size()
     d['outputs'] = []
-    for i in xrange(n_vout):
+    for i in range(n_vout):
         o = parse_TxOut(vds, i)
         d['outputs'].append(o)
 
diff --git a/src/ircthread.py b/src/ircthread.py
index 90631475..cf481903 100644
--- a/src/ircthread.py
+++ b/src/ircthread.py
@@ -26,11 +26,11 @@
 import socket
 import ssl
 import threading
-import Queue
+import queue
 import irc.client
-from utils import logger
-from utils import Hash
-from version import VERSION
+from .utils import logger
+from .utils import Hash
+from .version import VERSION
 
 out_msg = []
 
@@ -61,7 +61,7 @@ def __init__(self, processor, config):
         self.pruning_limit = config.get('leveldb', 'pruning_limit')
         self.nick = 'E_' + self.nick
         self.password = None
-        self.who_queue = Queue.Queue()
+        self.who_queue = queue.Queue()
 
     def getname(self):
         s = 'v' + VERSION + ' '
@@ -127,7 +127,7 @@ def who_thread(self):
         while not self.processor.shared.stopped():
             try:
                 connection, s = self.who_queue.get(timeout=1)
-            except Queue.Empty:
+            except queue.Empty:
                 continue
             #logger.info("who: "+ s)
             connection.who(s)
diff --git a/src/processor.py b/src/processor.py
index e9aab6ec..87d4211e 100644
--- a/src/processor.py
+++ b/src/processor.py
@@ -22,14 +22,14 @@
 # SOFTWARE.
 
 import json
-import Queue as queue
+import queue as queue
 import socket
 import threading
 import time
 import sys
 
-from utils import random_string, timestr, print_log
-from utils import logger
+from .utils import random_string, timestr, print_log
+from .utils import logger
 
 class Shared:
 
@@ -94,7 +94,7 @@ def run(self):
             try:
                 result = self.process(request)
                 self.push_response(session, {'id': msg_id, 'result': result})
-            except BaseException, e:
+            except BaseException as e:
                 self.push_response(session, {'id': msg_id, 'error':str(e)})
             except:
                 logger.error("process error", exc_info=True)
@@ -147,7 +147,7 @@ def pop_request(self):
         return self.request_queue.get()
 
     def get_session_by_address(self, address):
-        for x in self.sessions.values():
+        for x in list(self.sessions.values()):
             if x.address == address:
                 return x
 
@@ -197,7 +197,7 @@ def do_dispatch(self, session, request):
 
     def get_sessions(self):
         with self.lock:
-            r = self.sessions.values()
+            r = list(self.sessions.values())
         return r
 
     def add_session(self, session):
diff --git a/src/server_processor.py b/src/server_processor.py
index a6f87aec..b83d5f43 100644
--- a/src/server_processor.py
+++ b/src/server_processor.py
@@ -25,14 +25,14 @@
 import sys
 import threading
 import time
-import Queue
+import queue
 
 
-from processor import Processor
-from utils import Hash, print_log
-from version import VERSION
-from utils import logger
-from ircthread import IrcThread
+from .processor import Processor
+from .utils import Hash, print_log
+from .version import VERSION
+from .utils import logger
+from .ircthread import IrcThread
 
 
 
@@ -43,7 +43,7 @@ def __init__(self, config, shared):
         self.daemon = True
         self.config = config
         self.shared = shared
-        self.irc_queue = Queue.Queue()
+        self.irc_queue = queue.Queue()
         self.peers = {}
 
         if self.config.get('server', 'irc') == 'yes':
@@ -60,7 +60,7 @@ def read_irc_results(self):
         while True:
             try:
                 event, params = self.irc_queue.get(timeout=1)
-            except Queue.Empty:
+            except queue.Empty:
                 continue
             #logger.info(event + ' ' + repr(params))
             if event == 'join':
@@ -73,7 +73,7 @@ def read_irc_results(self):
 
 
     def get_peers(self):
-        return self.peers.values()
+        return list(self.peers.values())
 
 
     def process(self, request):
diff --git a/src/storage.py b/src/storage.py
index 05489ee5..05a0606f 100644
--- a/src/storage.py
+++ b/src/storage.py
@@ -28,8 +28,8 @@
 import sys
 import threading
 
-from processor import print_log, logger
-from utils import bc_address_to_hash_160, hash_160_to_pubkey_address, Hash, \
+from .processor import print_log, logger
+from .utils import bc_address_to_hash_160, hash_160_to_pubkey_address, Hash, \
     bytes8_to_int, bytes4_to_int, int_to_bytes8, \
     int_to_hex8, int_to_bytes4, int_to_hex4
 
@@ -52,7 +52,7 @@ def __init__(self, s):
         self.k = int(s[0:32].encode('hex'), 16)
         self.s = s[32:]
         if self.k==0 and self.s:
-            print "init error", len(self.s), "0x%0.64X" % self.k
+            print("init error", len(self.s), "0x%0.64X" % self.k)
             raise BaseException("z")
 
     def serialized(self):
@@ -69,7 +69,7 @@ def is_singleton(self, key):
         return len(self.s) == 40
 
     def get_singleton(self):
-        for i in xrange(256):
+        for i in range(256):
             if self.k == (1<<i):
                 return chr(i)
         raise BaseException("get_singleton")
@@ -77,7 +77,7 @@ def get_singleton(self):
     def indexof(self, c):
         assert self.k != 0 or self.s == ''
         x = 0
-        for i in xrange(ord(c)):
+        for i in range(ord(c)):
             if (self.k & (1<<i)) != 0:
                 x += 40
         return x
@@ -114,7 +114,7 @@ def get_hash(self, x, parent):
         x = 0
         v = 0
         hh = ''
-        for i in xrange(256):
+        for i in range(256):
             if (self.k&(1<<i)) != 0:
                 ss = self.s[x:x+40]
                 hh += ss[0:32]
@@ -132,7 +132,7 @@ def get_hash(self, x, parent):
     def from_dict(klass, d):
         k = 0
         s = ''
-        for i in xrange(256):
+        for i in range(256):
             if chr(i) in d:
                 k += 1<<i
                 h, value = d[chr(i)]
@@ -185,7 +185,7 @@ def write(self):
     def get_next(self, key):
         with self.lock:
             i = self.db.iterator(start=key)
-            k, _ = i.next()
+            k, _ = next(i)
             return k
 
 
@@ -325,7 +325,7 @@ def get_history(self, addr):
         out = set(out)
         # sort by height then tx_hash
         out = sorted(out)
-        return map(lambda x: {'height':x[0], 'tx_hash':x[1]}, out)
+        return [{'height':x[0], 'tx_hash':x[1]} for x in out]
 
     def get_address(self, txi):
         return self.db_addr.get(txi)
@@ -343,7 +343,7 @@ def write_undo_info(self, height, bitcoind_height, undo_info):
     @staticmethod
     def common_prefix(word1, word2):
         max_len = min(len(word1),len(word2))
-        for i in xrange(max_len):
+        for i in range(max_len):
             if word2[i] != word1[i]:
                 index = i
                 break
@@ -429,9 +429,9 @@ def update_node_hash(self, node, path, _hash, value):
     def update_hashes(self):
         nodes = {} # nodes to write
 
-        for i in xrange(KEYLENGTH, -1, -1):
+        for i in range(KEYLENGTH, -1, -1):
 
-            for node in self.hash_list.keys():
+            for node in list(self.hash_list.keys()):
                 if len(node) != i:
                     continue
 
@@ -468,7 +468,7 @@ def update_hashes(self):
                     self.hash_list[parent] = (parent_hash, parent_value)
 
 
-        for k, v in nodes.iteritems():
+        for k, v in nodes.items():
             self.put_node(k, v)
         # cleanup
         assert self.hash_list == {}
diff --git a/src/stratum_tcp.py b/src/stratum_tcp.py
index d7dad44b..152a327b 100644
--- a/src/stratum_tcp.py
+++ b/src/stratum_tcp.py
@@ -22,15 +22,15 @@
 # SOFTWARE.
 
 import json
-import Queue as queue
+import queue as queue
 import socket
 import select
 import threading
 import time
 import sys
 
-from processor import Session, Dispatcher
-from utils import print_log, logger
+from .processor import Session, Dispatcher
+from .utils import print_log, logger
 
 
 READ_ONLY = select.POLLIN | select.POLLPRI | select.POLLHUP | select.POLLERR
@@ -207,7 +207,7 @@ def check_do_handshake(session):
         while not self.shared.stopped():
 
             if self.shared.paused():
-                sessions = self.fd_to_session.keys()
+                sessions = list(self.fd_to_session.keys())
                 if sessions:
                     logger.info("closing %d sessions"%len(sessions))
                 for fd in sessions:
@@ -220,7 +220,7 @@ def check_do_handshake(session):
                 redo = []
             else:
                 now = time.time()
-                for fd, session in self.fd_to_session.items():
+                for fd, session in list(self.fd_to_session.items()):
                     # Anti-DOS: wait 0.01 second between requests
                     if now - session.time > 0.01 and session.message:
                         cmd = session.parse_message()
diff --git a/src/utils.py b/src/utils.py
index 99d8fcf4..c480421c 100644
--- a/src/utils.py
+++ b/src/utils.py
@@ -21,7 +21,7 @@
 # CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 # SOFTWARE.
 
-from itertools import imap
+
 import threading
 import time
 import hashlib
@@ -155,7 +155,7 @@ def bc_address_to_hash_160(addr):
 def b58encode(v):
     """encode v, which is a string of bytes, to base58."""
 
-    long_value = 0L
+    long_value = 0
     for (i, c) in enumerate(v[::-1]):
         long_value += (256**i) * ord(c)
 
@@ -180,7 +180,7 @@ def b58encode(v):
 
 def b58decode(v, length):
     """ decode v into a string of len bytes."""
-    long_value = 0L
+    long_value = 0
     for (i, c) in enumerate(v[::-1]):
         long_value += __b58chars.find(c) * (__b58base**i)
 
@@ -246,7 +246,7 @@ def init_logger():
     logger.setLevel(logging.INFO)
 
 def print_log(*args):
-    logger.info(" ".join(imap(str, args)))
+    logger.info(" ".join(map(str, args)))
 
 def print_warning(message):
     logger.warning(message)

From 00130b613e730d1e977c17db5fdbc1a3169c205d Mon Sep 17 00:00:00 2001
From: Justin Turner Arthur <justinarthur@gmail.com>
Date: Tue, 1 Mar 2016 02:24:39 -0600
Subject: [PATCH 02/18] Use bytes for most keys/values in the storage engine.
 Use binascii package for hex conversions.

bytes is similar to Python 2's str type.
---
 src/storage.py | 67 ++++++++++++++++++++++++--------------------------
 1 file changed, 32 insertions(+), 35 deletions(-)

diff --git a/src/storage.py b/src/storage.py
index 05a0606f..56cd67ef 100644
--- a/src/storage.py
+++ b/src/storage.py
@@ -23,9 +23,8 @@
 
 import plyvel
 import ast
-import hashlib
+from binascii import hexlify, unhexlify
 import os
-import sys
 import threading
 
 from .processor import print_log, logger
@@ -49,15 +48,14 @@
 class Node(object):
 
     def __init__(self, s):
-        self.k = int(s[0:32].encode('hex'), 16)
+        self.k = int.from_bytes(s[0:32], 'big')
         self.s = s[32:]
         if self.k==0 and self.s:
             print("init error", len(self.s), "0x%0.64X" % self.k)
             raise BaseException("z")
 
     def serialized(self):
-        k = "0x%0.64X" % self.k
-        k = k[2:].decode('hex')
+        k = self.k.to_bytes(32, 'big')
         assert len(k) == 32
         return k + self.s
 
@@ -65,7 +63,7 @@ def has(self, c):
         return (self.k & (1<<(ord(c)))) != 0
 
     def is_singleton(self, key):
-        assert self.s != ''
+        assert self.s != b''
         return len(self.s) == 40
 
     def get_singleton(self):
@@ -75,7 +73,7 @@ def get_singleton(self):
         raise BaseException("get_singleton")
 
     def indexof(self, c):
-        assert self.k != 0 or self.s == ''
+        assert self.k != 0 or self.s == b''
         x = 0
         for i in range(ord(c)):
             if (self.k & (1<<i)) != 0:
@@ -91,7 +89,7 @@ def get(self, c):
 
     def set(self, c, h, value):
         if h is None:
-            h = chr(0)*32
+            h = b'\x00' * 32
         vv = int_to_bytes8(value)
         item = h + vv
         assert len(item) == 40
@@ -110,10 +108,10 @@ def remove(self, c):
     def get_hash(self, x, parent):
         if x:
             assert self.k != 0
-        skip_string = x[len(parent)+1:] if x != '' else ''
+        skip_bytes = x[len(parent)+1:] if x != b'' else b''
         x = 0
         v = 0
-        hh = ''
+        hh = b''
         for i in range(256):
             if (self.k&(1<<i)) != 0:
                 ss = self.s[x:x+40]
@@ -121,7 +119,7 @@ def get_hash(self, x, parent):
                 v += bytes8_to_int(ss[32:40])
                 x += 40
         try:
-            _hash = Hash(skip_string + hh)
+            _hash = Hash(skip_bytes + hh)
         except:
             _hash = None
         if x:
@@ -131,18 +129,17 @@ def get_hash(self, x, parent):
     @classmethod
     def from_dict(klass, d):
         k = 0
-        s = ''
+        s = b''
         for i in range(256):
             if chr(i) in d:
                 k += 1<<i
                 h, value = d[chr(i)]
-                if h is None: h = chr(0)*32
+                if h is None: h = b'\x00'*32
                 vv = int_to_bytes8(value)
                 item = h + vv
                 assert len(item) == 40
                 s += item
-        k = "0x%0.64X" % k # 32 bytes
-        k = k[2:].decode('hex')
+        k = k.to_bytes(32, 'big')
         assert len(k) == 32
         out = k + s
         return Node(out)
@@ -162,7 +159,7 @@ def put(self, key, s):
 
     def get(self, key):
         s = self.cache.get(key)
-        if s == 'deleted':
+        if s == b'deleted':
             return None
         if s is None:
             with self.lock:
@@ -171,7 +168,7 @@ def get(self, key):
 
     def delete(self, key):
         self.batch.delete(key)
-        self.cache[key] = 'deleted'
+        self.cache[key] = b'deleted'
 
     def close(self):
         self.db.close()
@@ -243,7 +240,7 @@ def __init__(self, config, shared, test_reorgs):
         print_log("Pruning limit for spent outputs is %d."%self.pruning_limit)
         print_log("Reorg limit is %d blocks."%self.reorg_limit)
         print_log("Blockchain height", self.height)
-        print_log("UTXO tree root hash:", self.root_hash.encode('hex'))
+        print_log("UTXO tree root hash:", hexlify(self.root_hash))
         print_log("Coins in database:", coins)
 
     # convert between bitcoin addresses and 20 bytes keys used for storage.
@@ -270,7 +267,7 @@ def get_proof(self, addr):
         out = []
         for item in p:
             v = self.db_utxo.get(item)
-            out.append((item.encode('hex'), v.encode('hex')))
+            out.append((hexlify(item), hexlify(v)))
         return out
 
     def get_balance(self, addr):
@@ -293,7 +290,7 @@ def listunspent(self, addr):
                 if not k.startswith(key):
                     break
                 if len(k) == KEYLENGTH:
-                    txid = k[20:52].encode('hex')
+                    txid = hexlify(k[20:52])
                     txpos = bytes4_to_int(k[52:56])
                     h = bytes4_to_int(v[8:12])
                     v = bytes8_to_int(v[0:8])
@@ -315,9 +312,9 @@ def get_history(self, addr):
         while h:
             item = h[0:80]
             h = h[80:]
-            txi = item[0:32].encode('hex')
+            txi = hexlify(item[0:32])
             hi = bytes4_to_int(item[36:40])
-            txo = item[40:72].encode('hex')
+            txo = hexlify(item[40:72])
             ho = bytes4_to_int(item[76:80])
             out.append((hi, txi))
             out.append((ho, txo))
@@ -365,7 +362,7 @@ def add_key(self, target, value, height):
         path = self.get_path(target, new=True)
         if path is True:
             return
-        #print "add key: target", target.encode('hex'), "path", map(lambda x: x.encode('hex'), path)
+        #print "add key: target", hexlify(target), "path", map(lambda x: hexlify(x), path)
         parent = path[-1]
         parent_node = self.get_node(parent)
         n = len(parent)
@@ -411,7 +408,7 @@ def add_key(self, target, value, height):
             self.put_node(parent, parent_node)
 
         # write the new leaf
-        s = (int_to_hex8(value) + int_to_hex4(height)).decode('hex')
+        s = unhexlify(int_to_hex8(value) + int_to_hex4(height))
         self.db_utxo.put(target, s)
         # the hash of a leaf is the txid
         _hash = target[20:52]
@@ -481,12 +478,12 @@ def get_path(self, target, new=False):
 
         x = self.db_utxo.get(target)
         if not new and x is None:
-            raise BaseException('key not in tree', target.encode('hex'))
+            raise BaseException('key not in tree', hexlify(target))
 
         if new and x is not None:
-            # raise BaseException('key already in tree', target.encode('hex'))
+            # raise BaseException('key already in tree', hexlify(target))
             # occurs at block 91880 (duplicate txid)
-            print_log('key already in tree', target.encode('hex'))
+            print_log('key already in tree', hexlify(target))
             return True
 
         remaining = target
@@ -511,7 +508,7 @@ def get_path(self, target, new=False):
 
     def delete_key(self, leaf):
         path = self.get_path(leaf)
-        #print "delete key", leaf.encode('hex'), map(lambda x: x.encode('hex'), path)
+        #print "delete key", hexlify(leaf), map(lambda x: hexlify(x), path)
 
         s = self.db_utxo.get(leaf)
         self.db_utxo.delete(leaf)
@@ -526,7 +523,7 @@ def delete_key(self, leaf):
 
         # remove key if it has a single child
         if parent_node.is_singleton(parent):
-            #print "deleting parent", parent.encode('hex')
+            #print "deleting parent", hexlify(parent)
             self.db_utxo.delete(parent)
             if parent in self.hash_list:
                 del self.hash_list[parent]
@@ -542,7 +539,7 @@ def delete_key(self, leaf):
             new_skip = otherleaf[len(gp)+1:]
             gp_items.set(letter, None, 0)
             self.set_skip(gp+ letter, new_skip)
-            #print "gp new_skip", gp.encode('hex'), new_skip.encode('hex')
+            #print "gp new_skip", hexlify(gp), hexlify(new_skip)
             self.put_node(gp, gp_items)
 
             # note: k is not necessarily a leaf
@@ -579,7 +576,7 @@ def save_height(self, block_hash, block_height):
 
     def add_to_history(self, addr, tx_hash, tx_pos, value, tx_height):
         key = self.address_to_key(addr)
-        txo = (tx_hash + int_to_hex4(tx_pos)).decode('hex')
+        txo = unhexlify(tx_hash + int_to_hex4(tx_pos))
         # write the new history
         self.add_key(key + txo, value, tx_height)
         # backlink
@@ -588,7 +585,7 @@ def add_to_history(self, addr, tx_hash, tx_pos, value, tx_height):
 
     def revert_add_to_history(self, addr, tx_hash, tx_pos, value, tx_height):
         key = self.address_to_key(addr)
-        txo = (tx_hash + int_to_hex4(tx_pos)).decode('hex')
+        txo = unhexlify(tx_hash + int_to_hex4(tx_pos))
         # delete
         self.delete_key(key + txo)
         # backlink
@@ -615,7 +612,7 @@ def set_spent(self, addr, txi, txid, index, height, undo):
         # add to history
         s = self.db_hist.get(addr)
         if s is None: s = ''
-        txo = (txid + int_to_hex4(index) + int_to_hex4(height)).decode('hex')
+        txo = unhexlify(txid + int_to_hex4(index) + int_to_hex4(height))
         s += txi + int_to_bytes4(in_height) + txo
         s = s[ -80*self.pruning_limit:]
         self.db_hist.put(addr, s)
@@ -650,7 +647,7 @@ def import_transaction(self, txid, tx, block_height, touched_addr):
 
         prev_addr = []
         for i, x in enumerate(tx.get('inputs')):
-            txi = (x.get('prevout_hash') + int_to_hex4(x.get('prevout_n'))).decode('hex')
+            txi = unhexlify(x.get('prevout_hash') + int_to_hex4(x.get('prevout_n')))
             addr = self.get_address(txi)
             if addr is not None:
                 self.set_spent(addr, txi, txid, i, block_height, undo)
@@ -681,7 +678,7 @@ def revert_transaction(self, txid, tx, block_height, touched_addr, undo):
         for i, x in reversed(list(enumerate(tx.get('inputs')))):
             addr = prev_addr[i]
             if addr is not None:
-                txi = (x.get('prevout_hash') + int_to_hex4(x.get('prevout_n'))).decode('hex')
+                txi = unhexlify(x.get('prevout_hash') + int_to_hex4(x.get('prevout_n')))
                 self.revert_set_spent(addr, txi, undo)
                 touched_addr.add(addr)
 

From 2135b58e34dda66624048d761a2006f77d57f597 Mon Sep 17 00:00:00 2001
From: Justin Turner Arthur <justinarthur@gmail.com>
Date: Fri, 4 Mar 2016 03:48:57 -0600
Subject: [PATCH 03/18] A unit test for expected results of deserialize
 module's parse_Transasction in Python 3.

---
 src/test/test_deserialize.py | 38 ++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 src/test/test_deserialize.py

diff --git a/src/test/test_deserialize.py b/src/test/test_deserialize.py
new file mode 100644
index 00000000..25b4ae0a
--- /dev/null
+++ b/src/test/test_deserialize.py
@@ -0,0 +1,38 @@
+import unittest
+try:
+    from electrumserver.deserialize import BCDataStream, parse_Transaction
+except ImportError:
+    from src.deserialize import BCDataStream, parse_Transaction
+
+class DeserializeTest(unittest.TestCase):
+    example_tx_bytes = b'\x01\x00\x00\x00\x01{\x1e\xab\xe0 \x9b\x1f\xe7\x94\x12Eu\xef\x80pW\xc7z\xda!8\xaeO\xa8\xd6' \
+        b'\xc4\xde\x03\x98\xa1O?\x00\x00\x00\x00\x00\xff\xff\xff\xff\x01\xf0\xca\x05*\x01\x00\x00\x00\x19v\xa9\x14' \
+        b'\xcb\xc2\nvd\xf2\xf6\x9eSU\xaaBpE\xbc\x15\xe7\xc6\xc7r\x88\xac\x00\x00\x00\x00'
+
+    def test_transaction_parsing(self):
+        vds = BCDataStream()
+        vds.write(self.example_tx_bytes)
+        parsed_tx = parse_Transaction(vds, is_coinbase=False)
+        expected_tx = {
+            'inputs': [
+                {
+                    'prevout_n': 0,
+                    'sequence': 4294967295,
+                    'prevout_hash': b'3f4fa19803dec4d6a84fae3821da7ac7577080ef75451294e71f9b20e0ab1e7b'
+                }
+            ],
+            'outputs': [
+                {'value': 4999990000,
+                 'raw_output_script': b'76a914cbc20a7664f2f69e5355aa427045bc15e7c6c77288ac',
+                 'address': b'KaNd8ybzTDYKpyMB9X2dstvMwo5ogo5bT',
+                 'index': 0
+                 }
+            ],
+            'version': 1,
+            'lockTime': 0
+        }
+        self.assertEqual(parsed_tx, expected_tx)
+
+
+if __name__ == '__main__':
+    unittest.main()

From ec4fdfccb893193c190ac7534f20ea5f0211b71a Mon Sep 17 00:00:00 2001
From: Justin Turner Arthur <justinarthur@gmail.com>
Date: Fri, 4 Mar 2016 03:50:42 -0600
Subject: [PATCH 04/18] Use jsonrpc-pelix to get Python 3-compatible
 jsonrpclib. At some point we should consider another library.

---
 setup.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/setup.py b/setup.py
index 84c349af..a23d1b40 100644
--- a/setup.py
+++ b/setup.py
@@ -4,7 +4,7 @@
     name="electrum-server",
     version="1.0",
     scripts=['run_electrum_server.py','electrum-server'],
-    install_requires=['plyvel','jsonrpclib', 'irc >= 11, <=14.0'],
+    install_requires=['plyvel','jsonrpclib-pelix', 'irc>=11, <=14.0'],
     package_dir={
         'electrumserver':'src'
         },

From dfdca6a08e3a4a3351a1dd6bbf522ec6f7812008 Mon Sep 17 00:00:00 2001
From: Justin Turner Arthur <justinarthur@gmail.com>
Date: Fri, 4 Mar 2016 09:56:50 -0600
Subject: [PATCH 05/18] Fix byte-string compatibility with Python 3 in hashing
 utilities.

---
 src/utils.py | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/utils.py b/src/utils.py
index c480421c..55a8a6db 100644
--- a/src/utils.py
+++ b/src/utils.py
@@ -26,8 +26,10 @@
 import time
 import hashlib
 import struct
+from binascii import hexlify, unhexlify
+from collections import deque
 
-__b58chars = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
+__b58chars = b'123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
 __b58base = len(__b58chars)
 
 global PUBKEY_ADDRESS
@@ -36,16 +38,16 @@
 SCRIPT_ADDRESS = 5
 
 def rev_hex(s):
-    return s.decode('hex')[::-1].encode('hex')
+    return hexlify(unhexlify(s)[::-1])
 
 
 Hash = lambda x: hashlib.sha256(hashlib.sha256(x).digest()).digest()
 
 
-hash_encode = lambda x: x[::-1].encode('hex')
+hash_encode = lambda x: hexlify(x[::-1])
 
 
-hash_decode = lambda x: x.decode('hex')[::-1]
+hash_decode = lambda x: unhexlify(x)[::-1]
 
 
 def header_to_string(res):
@@ -140,7 +142,7 @@ def hash_160_to_address(h160, addrtype = 0):
     """
     if h160 is None or len(h160) is not 20:
         return None
-    vh160 = chr(addrtype) + h160
+    vh160 = bytes((addrtype,)) + h160
     h = Hash(vh160)
     addr = vh160 + h[0:4]
     return b58encode(addr)
@@ -157,14 +159,14 @@ def b58encode(v):
 
     long_value = 0
     for (i, c) in enumerate(v[::-1]):
-        long_value += (256**i) * ord(c)
+        long_value += (256**i) * c
 
-    result = ''
+    result = deque()
     while long_value >= __b58base:
         div, mod = divmod(long_value, __b58base)
-        result = __b58chars[mod] + result
+        result.appendleft(__b58chars[mod])
         long_value = div
-    result = __b58chars[long_value] + result
+    result.appendleft(__b58chars[long_value])
 
     # Bitcoin does a little leading-zero-compression:
     # leading 0-bytes in the input become leading-1s
@@ -175,7 +177,8 @@ def b58encode(v):
         else:
             break
 
-    return (__b58chars[0]*nPad) + result
+    result.extendleft(__b58chars[0:1]*nPad)
+    return bytes(result)
 
 
 def b58decode(v, length):

From 094f406d098d87f8cadba6122535ad68c32153f1 Mon Sep 17 00:00:00 2001
From: Justin Turner Arthur <justinarthur@gmail.com>
Date: Fri, 4 Mar 2016 09:58:53 -0600
Subject: [PATCH 06/18] Fix byte-string compatibility with Python 3 in
 transaction parsing stack.

---
 src/deserialize.py | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/src/deserialize.py b/src/deserialize.py
index 7443f8b1..d5a8d288 100644
--- a/src/deserialize.py
+++ b/src/deserialize.py
@@ -6,6 +6,7 @@
 import string
 import struct
 import types
+from binascii import hexlify
 
 from .utils import hash_160_to_pubkey_address, hash_160_to_script_address, public_key_to_pubkey_address, hash_encode,\
     hash_160
@@ -117,7 +118,7 @@ def write_uint64(self, val):
         return self._write_num('<Q', val)
 
     def read_compact_size(self):
-        size = ord(self.input[self.read_cursor])
+        size = self.input[self.read_cursor]
         self.read_cursor += 1
         if size == 253:
             size = self._read_num('<H')
@@ -172,7 +173,7 @@ def __init__(self, name, enumList):
         for x in enumList:
             if isinstance(x, tuple):
                 x, i = x
-            if not isinstance(x, bytes):
+            if not isinstance(x, str):
                 raise EnumException("enum name is not a string: %r" % x)
             if not isinstance(i, int):
                 raise EnumException("enum value is not an integer: %r" % i)
@@ -196,15 +197,11 @@ def __getattr__(self, attr):
     def whatis(self, value):
         return self.reverseLookup[value]
 
-
-# This function comes from bitcointools, bct-LICENSE.txt.
-def long_hex(bytes):
-    return bytes.encode('hex_codec')
-
+long_hex = hexlify
 
 # This function comes from bitcointools, bct-LICENSE.txt.
 def short_hex(bytes):
-    t = bytes.encode('hex_codec')
+    t = hexlify(bytes)
     if len(t) < 11:
         return t
     return t[0:4]+"..."+t[-4:]
@@ -224,7 +221,7 @@ def parse_TxOut(vds, i):
     d['value'] = vds.read_int64()
     scriptPubKey = vds.read_bytes(vds.read_compact_size())
     d['address'] = get_address_from_output_script(scriptPubKey)
-    d['raw_output_script'] = scriptPubKey.encode('hex')
+    d['raw_output_script'] = hexlify(scriptPubKey)
     d['index'] = i
     return d
 
@@ -274,13 +271,13 @@ def script_GetOp(bytes):
     i = 0
     while i < len(bytes):
         vch = None
-        opcode = ord(bytes[i])
+        opcode = bytes[i]
         i += 1
 
         if opcode <= opcodes.OP_PUSHDATA4:
             nSize = opcode
             if opcode == opcodes.OP_PUSHDATA1:
-                nSize = ord(bytes[i])
+                nSize = bytes[i]
                 i += 1
             elif opcode == opcodes.OP_PUSHDATA2:
                 (nSize,) = struct.unpack_from('<H', bytes, i)
@@ -331,9 +328,9 @@ def match_decoded(decoded, to_match):
 
 
 
-def get_address_from_output_script(bytes):
+def get_address_from_output_script(output_script_bytes):
     try:
-        decoded = [ x for x in script_GetOp(bytes) ]
+        decoded = [ x for x in script_GetOp(output_script_bytes) ]
     except:
         return None
 

From 9256370072bdf0a426b3495383ea4d8a766749e5 Mon Sep 17 00:00:00 2001
From: Justin Turner Arthur <justinarthur@gmail.com>
Date: Fri, 4 Mar 2016 15:04:13 -0600
Subject: [PATCH 07/18] Fix incorrect address being checked by tx parsing test.

---
 src/test/test_deserialize.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/test/test_deserialize.py b/src/test/test_deserialize.py
index 25b4ae0a..4265f1ce 100644
--- a/src/test/test_deserialize.py
+++ b/src/test/test_deserialize.py
@@ -24,7 +24,7 @@ def test_transaction_parsing(self):
             'outputs': [
                 {'value': 4999990000,
                  'raw_output_script': b'76a914cbc20a7664f2f69e5355aa427045bc15e7c6c77288ac',
-                 'address': b'KaNd8ybzTDYKpyMB9X2dstvMwo5ogo5bT',
+                 'address': b'1KaNd8ybzTDYKpyMB9X2dstvMwo5ogo5bT',
                  'index': 0
                  }
             ],

From b589e95c40c39e822d190f50a1073547e7a42a95 Mon Sep 17 00:00:00 2001
From: Justin Turner Arthur <justinarthur@gmail.com>
Date: Fri, 4 Mar 2016 15:05:57 -0600
Subject: [PATCH 08/18] Update test_utils tests to Python 3 hex conversion
 conventions. Assume bytes instead of character strings for most things.

---
 src/test/test_utils.py | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/src/test/test_utils.py b/src/test/test_utils.py
index f7e22bf1..81d87e0d 100644
--- a/src/test/test_utils.py
+++ b/src/test/test_utils.py
@@ -1,28 +1,28 @@
-__author__ = 'erasmospunk'
-
+from binascii import hexlify, unhexlify
 import unittest
-from utils import hash_160_to_address, bc_address_to_hash_160
+try:
+    from electrumserver.utils import hash_160_to_address, bc_address_to_hash_160
+except ImportError:
+    from src.utils import hash_160_to_address, bc_address_to_hash_160
 
 
 class UtilTest(unittest.TestCase):
 
     def test_hash_160_to_address(self):
         self.assertEqual(hash_160_to_address(None), None)
-        self.assertEqual(hash_160_to_address('04e9fca1'.decode('hex')), None)
-        self.assertEqual(hash_160_to_address('04e9fca1f96e021dfaf35bbea267ec2c60787c1b1337'.decode('hex')), None)
-        self.assertEqual(hash_160_to_address('1ad3b0b711f211655a01142fbb8fecabe8e30b93'.decode('hex')),
-                         '13SrAVFPVW1txSj34B8Bd6hnDbyPsVGa92')
+        self.assertEqual(hash_160_to_address(unhexlify('04e9fca1')), None)
+        self.assertEqual(hash_160_to_address(unhexlify('04e9fca1f96e021dfaf35bbea267ec2c60787c1b1337')), None)
+        self.assertEqual(hash_160_to_address(unhexlify('1ad3b0b711f211655a01142fbb8fecabe8e30b93')),
+                         b'13SrAVFPVW1txSj34B8Bd6hnDbyPsVGa92')
 
 
     def test_bc_address_to_hash_160(self):
         self.assertEqual(bc_address_to_hash_160(None), None)
-        self.assertEqual(bc_address_to_hash_160(''), None)
-        self.assertEqual(bc_address_to_hash_160('13SrAVFPVW1txSj34B8Bd6hnDbyPsVGa921337'), None)
-        self.assertEqual(bc_address_to_hash_160('13SrAVFPVW1txSj34B8Bd6hnDbyPsVGa92').encode('hex'),
-                                                '1ad3b0b711f211655a01142fbb8fecabe8e30b93')
-
+        self.assertEqual(bc_address_to_hash_160(b''), None)
+        self.assertEqual(bc_address_to_hash_160(b'13SrAVFPVW1txSj34B8Bd6hnDbyPsVGa921337'), None)
+        self.assertEqual(hexlify(bc_address_to_hash_160(b'13SrAVFPVW1txSj34B8Bd6hnDbyPsVGa92')),
+                                                b'1ad3b0b711f211655a01142fbb8fecabe8e30b93')
 
 
 if __name__ == '__main__':
     unittest.main()
-

From 870c202ccb6d8e66cbb9a19d874628ca0264874d Mon Sep 17 00:00:00 2001
From: Justin Turner Arthur <justinarthur@gmail.com>
Date: Fri, 4 Mar 2016 15:09:14 -0600
Subject: [PATCH 09/18] Base 58 decoding utility function to return bytes
 instead of character string response.

---
 src/utils.py | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/utils.py b/src/utils.py
index 55a8a6db..f0a04698 100644
--- a/src/utils.py
+++ b/src/utils.py
@@ -28,6 +28,7 @@
 import struct
 from binascii import hexlify, unhexlify
 from collections import deque
+from itertools import repeat
 
 __b58chars = b'123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
 __b58base = len(__b58chars)
@@ -172,7 +173,7 @@ def b58encode(v):
     # leading 0-bytes in the input become leading-1s
     nPad = 0
     for c in v:
-        if c == '\0':
+        if c == 0:
             nPad += 1
         else:
             break
@@ -187,12 +188,12 @@ def b58decode(v, length):
     for (i, c) in enumerate(v[::-1]):
         long_value += __b58chars.find(c) * (__b58base**i)
 
-    result = ''
+    result = deque()
     while long_value >= 256:
         div, mod = divmod(long_value, 256)
-        result = chr(mod) + result
+        result.appendleft(mod)
         long_value = div
-    result = chr(long_value) + result
+    result.appendleft(long_value)
 
     nPad = 0
     for c in v:
@@ -201,11 +202,11 @@ def b58decode(v, length):
         else:
             break
 
-    result = chr(0)*nPad + result
+    result.extendleft(repeat(0, nPad))
     if length is not None and len(result) != length:
         return None
 
-    return result
+    return bytes(result)
 
 
 def EncodeBase58Check(vchIn):

From 97cc9c60b9d73cabbe17b438e62ff0ff5957e76a Mon Sep 17 00:00:00 2001
From: Johann Bauer <bauerj@bauerj.eu>
Date: Sat, 5 Mar 2016 18:31:42 +0100
Subject: [PATCH 10/18] Add `.travis.yml` for continuous integration

---
 .travis.yml | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 .travis.yml

diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 00000000..06d531e7
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,16 @@
+# The version of libleveldb in 12.04 is too old, better use trusty (14.04)
+sudo: required
+dist: trusty
+language: python
+python:
+  - "3.2"
+  - "3.3"
+  - "3.4"
+  - "pypy3"
+# command to install dependencies
+install:
+  - sudo apt-get install -y libleveldb-dev python-leveldb
+  - travis_retry python setup.py install
+# command to run tests
+script: 
+  - nosetests

From 7c6aec3bbc6a9232eab444a786222301a1536c80 Mon Sep 17 00:00:00 2001
From: Johann Bauer <bauerj@bauerj.eu>
Date: Sat, 5 Mar 2016 22:56:52 +0100
Subject: [PATCH 11/18] Add codecov.io coverage reports

---
 .travis.yml | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/.travis.yml b/.travis.yml
index 06d531e7..b2c4cbad 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,15 +2,30 @@
 sudo: required
 dist: trusty
 language: python
+
 python:
   - "3.2"
   - "3.3"
   - "3.4"
   - "pypy3"
+
+before_install:
+  - pip install codecov
+  - pip install nose-cov
+
 # command to install dependencies
 install:
   - sudo apt-get install -y libleveldb-dev python-leveldb
   - travis_retry python setup.py install
+
 # command to run tests
 script: 
-  - nosetests
+  - nosetests --with-coverage
+
+after_success:
+  - codecov
+
+matrix:
+  fast_finish: true
+  allow_failures:
+    - python: pypy3

From f4e9c5ef045ed76bd66bc1d72ca11b9c39b2c784 Mon Sep 17 00:00:00 2001
From: Johann Bauer <bauerj@bauerj.eu>
Date: Sat, 5 Mar 2016 23:09:59 +0100
Subject: [PATCH 12/18] Add badges for coverage and build status to README

---
 .travis.yml | 1 +
 README.md   | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/.travis.yml b/.travis.yml
index b2c4cbad..560b0ba0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -20,6 +20,7 @@ install:
 
 # command to run tests
 script: 
+  - nosetests
   - nosetests --with-coverage
 
 after_success:
diff --git a/README.md b/README.md
index e9f1eb36..84eac4a8 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,6 @@
+[![codecov.io](https://codecov.io/github/bauerj/electrum-server/coverage.svg?branch=python3-migration)](https://codecov.io/github/bauerj/electrum-server?branch=python3-migration)
+[![Build Status](https://travis-ci.org/bauerj/electrum-server.svg?branch=python3-migration)](https://travis-ci.org/bauerj/electrum-server)
+
 Electrum-server for the Electrum client
 =========================================
 

From 1abef458672c90361d4ecb6d41d5a9266c5d7754 Mon Sep 17 00:00:00 2001
From: Justin Turner Arthur <justinarthur@gmail.com>
Date: Tue, 8 Mar 2016 01:54:10 -0600
Subject: [PATCH 13/18] A couple of benchmarking scripts for comparing
 approaches and platforms.

---
 src/test/benchmark_byte_prepends.py | 36 +++++++++++++++++++++++++++++
 src/test/benchmark_deserialize.py   | 10 ++++++++
 2 files changed, 46 insertions(+)
 create mode 100644 src/test/benchmark_byte_prepends.py
 create mode 100644 src/test/benchmark_deserialize.py

diff --git a/src/test/benchmark_byte_prepends.py b/src/test/benchmark_byte_prepends.py
new file mode 100644
index 00000000..f24d7411
--- /dev/null
+++ b/src/test/benchmark_byte_prepends.py
@@ -0,0 +1,36 @@
+if __name__ == '__main__':
+    from timeit import timeit
+    from sys import version
+
+    basic_setup = "example_sequence = b'\\x00\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f !\"#$%&\\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\\x7f\\x80\\x81\\x82\\x83\\x84\\x85\\x86\\x87\\x88\\x89\\x8a\\x8b\\x8c\\x8d\\x8e\\x8f\\x90\\x91\\x92\\x93\\x94\\x95\\x96\\x97\\x98\\x99\\x9a\\x9b\\x9c\\x9d\\x9e\\x9f\\xa0\\xa1\\xa2\\xa3\\xa4\\xa5\\xa6\\xa7\\xa8\\xa9\\xaa\\xab\\xac\\xad\\xae\\xaf\\xb0\\xb1\\xb2\\xb3\\xb4\\xb5\\xb6\\xb7\\xb8\\xb9\\xba\\xbb\\xbc\\xbd\\xbe\\xbf\\xc0\\xc1\\xc2\\xc3\\xc4\\xc5\\xc6\\xc7\\xc8\\xc9\\xca\\xcb\\xcc\\xcd\\xce\\xcf\\xd0\\xd1\\xd2\\xd3\\xd4\\xd5\\xd6\\xd7\\xd8\\xd9\\xda\\xdb\\xdc\\xdd\\xde\\xdf\\xe0\\xe1\\xe2\\xe3\\xe4\\xe5\\xe6\\xe7\\xe8\\xe9\\xea\\xeb\\xec\\xed\\xee\\xef\\xf0\\xf1\\xf2\\xf3\\xf4\\xf5\\xf6\\xf7\\xf8\\xf9\\xfa\\xfb\\xfc\\xfd\\xfe\\xff'"
+
+    print("On {},".format(version))
+    test_bytearray_append_then_reverse = """thing=bytearray()
+for byte in example_sequence:
+    thing.append(byte)
+result = thing[::-1]"""
+    time = timeit(test_bytearray_append_then_reverse, basic_setup, number=10000)
+    print('appending to a bytearray then reversing it takes {:.20f}s.'.format(time))
+
+
+    setup_deque_appendleft = "from collections import deque\n" + basic_setup
+    test_deque_appendleft = """thing=deque()
+for byte in example_sequence:
+    thing.appendleft(byte)
+result = bytes(thing)"""
+    time = timeit(test_deque_appendleft, setup_deque_appendleft, number=10000)
+    print('Left-appending to a deque then converting to bytes takes {:.20f}s.'.format(time))
+
+    test_concat_new_bytes = """thing=bytes()
+for byte in example_sequence:
+    thing = bytes((byte,)) + thing
+result = thing"""
+    time = timeit(test_concat_new_bytes, basic_setup, number=10000)
+    print('Converting the int to a single-byte bytes then concatenating takes {:.20f}s.'.format(time))
+
+    test_concat_sliced_bytes = """thing=bytes()
+for i in range(0, len(example_sequence)):
+    thing = example_sequence[i:i+1] + thing
+result = thing"""
+    time = timeit(test_concat_sliced_bytes, basic_setup, number=10000)
+    print('Slicing single-byte bytes then concatenating takes {:.20f}s.'.format(time))
\ No newline at end of file
diff --git a/src/test/benchmark_deserialize.py b/src/test/benchmark_deserialize.py
new file mode 100644
index 00000000..59140b32
--- /dev/null
+++ b/src/test/benchmark_deserialize.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+from timeit import timeit
+from sys import version
+
+if __name__ == '__main__':
+    parse_test_setup="from src.deserialize import BCDataStream, parse_Transaction\nexample_tx_bytes = b'\\x01\\x00\\x00\\x00\\x01{\\x1e\\xab\\xe0 \\x9b\\x1f\\xe7\\x94\\x12Eu\\xef\\x80pW\\xc7z\\xda!8\\xaeO\\xa8\\xd6\\xc4\\xde\\x03\\x98\\xa1O?\\x00\\x00\\x00\\x00\\x00\\xff\\xff\\xff\\xff\\x01\\xf0\\xca\\x05*\\x01\\x00\\x00\\x00\\x19v\\xa9\\x14\\xcb\\xc2\\nvd\\xf2\\xf6\\x9eSU\\xaaBpE\\xbc\\x15\\xe7\\xc6\\xc7r\\x88\\xac\\x00\\x00\\x00\\x00'"
+    parse_test_run="vds = BCDataStream()\nvds.write(example_tx_bytes)\nparsed_tx = parse_Transaction(vds, is_coinbase=False)"
+    print("Running...")
+    time = timeit(parse_test_run, parse_test_setup, number=100000)
+    print("Took {} seconds in {}".format(time, version))
\ No newline at end of file

From c23a75e7f558921f24a9712c389270d9789572ea Mon Sep 17 00:00:00 2001
From: Justin Turner Arthur <justinarthur@gmail.com>
Date: Tue, 8 Mar 2016 13:32:09 -0600
Subject: [PATCH 14/18] Unit tests for header transformations.

---
 src/test/test_utils.py | 42 +++++++++++++++++++++++++++++++++++++-----
 1 file changed, 37 insertions(+), 5 deletions(-)

diff --git a/src/test/test_utils.py b/src/test/test_utils.py
index 81d87e0d..7caf54bd 100644
--- a/src/test/test_utils.py
+++ b/src/test/test_utils.py
@@ -1,13 +1,12 @@
 from binascii import hexlify, unhexlify
 import unittest
 try:
-    from electrumserver.utils import hash_160_to_address, bc_address_to_hash_160
+    from electrumserver.utils import hash_160_to_address, bc_address_to_hash_160, header_from_string, header_to_string
 except ImportError:
-    from src.utils import hash_160_to_address, bc_address_to_hash_160
+    from src.utils import hash_160_to_address, bc_address_to_hash_160, header_from_string, header_to_string
 
 
 class UtilTest(unittest.TestCase):
-
     def test_hash_160_to_address(self):
         self.assertEqual(hash_160_to_address(None), None)
         self.assertEqual(hash_160_to_address(unhexlify('04e9fca1')), None)
@@ -15,13 +14,46 @@ def test_hash_160_to_address(self):
         self.assertEqual(hash_160_to_address(unhexlify('1ad3b0b711f211655a01142fbb8fecabe8e30b93')),
                          b'13SrAVFPVW1txSj34B8Bd6hnDbyPsVGa92')
 
-
     def test_bc_address_to_hash_160(self):
         self.assertEqual(bc_address_to_hash_160(None), None)
         self.assertEqual(bc_address_to_hash_160(b''), None)
         self.assertEqual(bc_address_to_hash_160(b'13SrAVFPVW1txSj34B8Bd6hnDbyPsVGa921337'), None)
         self.assertEqual(hexlify(bc_address_to_hash_160(b'13SrAVFPVW1txSj34B8Bd6hnDbyPsVGa92')),
-                                                b'1ad3b0b711f211655a01142fbb8fecabe8e30b93')
+                         b'1ad3b0b711f211655a01142fbb8fecabe8e30b93')
+
+    def test_headers_from_string(self):
+        block_hex = b"03000000855d154359b794c6ba2c5586cf6278eee5bd658faa954200000000000000000035e95b187fb0d5175f681c2" \
+                    b"a1c499c3c91a0781c91679545a1fcabba2cd7cd801b04bd5515081518aa8afeaf020100000001000000000000000000" \
+                    b"0000000000000000000000000000000000000000000000ffffffff25035b9d05384d2f040f04bd550894251c009a050" \
+                    b"0000f5b4254434368696e612e636f6d5d20000000000100f90295000000001976a9142c30a6aaac6d96687291475d7d" \
+                    b"52f4b469f665a688ac0000000001000000018651ed89909def949ee3e05631bb332f339f4c667b0af7e2d94e7940a45" \
+                    b"68a21000000006a473044022059c947c745d94d1019990f39b2c938c9ce3e79fe9a650cff01589ec3b5ed2c2c02206d" \
+                    b"cff5e15ae6aa9c7d44308f16963dd5ad1dd3229e923c9de3ae1c14f6f91a02012102163e80de410646145142636833d" \
+                    b"8a92de4bb5c99e49bd52be5346fb1030628d4ffffffff0250ac6002000000001976a9145ca26d65ee83f441ef98b624" \
+                    b"763a305d50eb36cf88aca0860100000000001976a914838eb1034b719f9c47ab853aee63d505e4176a8388ac00000000"
+        block_bytes = unhexlify(block_hex)
+        block_header_bytes = block_bytes[0:80]
+        header = header_from_string(block_header_bytes)
+        self.assertEqual(header['version'], 3)
+        self.assertEqual(header['prev_block_hash'], b'0000000000000000004295aa8f65bde5ee7862cf86552cbac694b75943155d85')
+        self.assertEqual(header['merkle_root'], b'80cdd72cbaabfca1459567911c78a0913c9c491c2a1c685f17d5b07f185be935')
+        self.assertEqual(header['timestamp'], 1438450715)
+        self.assertEqual(header['bits'], 404031509)
+        self.assertEqual(header['nonce'], 2952694442)
+
+    def test_headers_to_string(self):
+        header = {
+            'version': 1,
+            'prev_block_hash': b'00000000000008a3a41b85b8b29ad444def299fee21793cd8b9e567eab02cd81',
+            'merkle_root': b'2b12fcf1b09288fcaff797d71e950e71ae42b91e8bdb2304758dfcffc2b620e3',
+            'timestamp': 1305998791,
+            'bits': 440711666,
+            'nonce': 2504433986,
+        }
+        header_hex = header_to_string(header)
+        expected_header_hex = b'0100000081cd02ab7e569e8bcd9317e2fe99f2de44d49ab2b8851ba4a308000000000000e320b6c2fffc8' \
+                              b'd750423db8b1eb942ae710e951ed797f7affc8892b0f1fc122bc7f5d74df2b9441a42a14695'
+        self.assertEqual(header_hex, expected_header_hex)
 
 
 if __name__ == '__main__':

From 369d3fd6a88a1f7f6fb7c4e353df337bb12df649 Mon Sep 17 00:00:00 2001
From: Justin Turner Arthur <justinarthur@gmail.com>
Date: Tue, 8 Mar 2016 13:32:42 -0600
Subject: [PATCH 15/18] Make int to hex functions Python 3-compatible.

---
 src/utils.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/utils.py b/src/utils.py
index f0a04698..81712321 100644
--- a/src/utils.py
+++ b/src/utils.py
@@ -81,11 +81,11 @@ def bytes8_to_int(s):
 
 
 def int_to_hex4(i):
-    return int_to_bytes4(i).encode('hex')
+    return hexlify(int_to_bytes4(i))
 
 
 def int_to_hex8(i):
-    return int_to_bytes8(i).encode('hex')
+    return hexlify(int_to_bytes8(i))
 
 
 def header_from_string(s):

From 9e0051f061dbeccb260d2d0b2d80eef4ecb0b1cd Mon Sep 17 00:00:00 2001
From: Justin Turner Arthur <justinarthur@gmail.com>
Date: Sat, 17 Dec 2016 18:33:36 -0600
Subject: [PATCH 16/18] leveldb data stored as bytes, not strings.

---
 src/storage.py | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/src/storage.py b/src/storage.py
index 56cd67ef..0bbc03c2 100644
--- a/src/storage.py
+++ b/src/storage.py
@@ -207,14 +207,14 @@ def __init__(self, config, shared, test_reorgs):
             logger.error('db init', exc_info=True)
             self.shared.stop()
         try:
-            self.last_hash, self.height, db_version = ast.literal_eval(self.db_undo.get('height'))
+            self.last_hash, self.height, db_version = ast.literal_eval(self.get(b'height'))
         except:
             print_log('Initializing database')
             self.height = 0
             self.last_hash = GENESIS_HASH
             self.pruning_limit = config.getint('leveldb', 'pruning_limit')
             db_version = DB_VERSION
-            self.put_node('', Node.from_dict({}))
+            self.put_node(b'', Node.from_dict({}))
         # check version
         if db_version != DB_VERSION:
             print_log("Your database '%s' is deprecated. Please create a new database"%self.dbpath)
@@ -222,19 +222,19 @@ def __init__(self, config, shared, test_reorgs):
             return
         # pruning limit
         try:
-            self.pruning_limit = ast.literal_eval(self.db_undo.get('limit'))
+            self.pruning_limit = ast.literal_eval(self.db_undo.get(b'limit'))
         except:
             self.pruning_limit = config.getint('leveldb', 'pruning_limit')
-            self.db_undo.put('version', repr(self.pruning_limit))
+        self.db_undo.put(b'version', repr(self.pruning_limit).encode("utf-8"))
         # reorg limit
         try:
-            self.reorg_limit = ast.literal_eval(self.db_undo.get('reorg_limit'))
+            self.reorg_limit = ast.literal_eval(self.db_undo.get(b'reorg_limit'))
         except:
             self.reorg_limit = config.getint('leveldb', 'reorg_limit')
-            self.db_undo.put('reorg_limit', repr(self.reorg_limit))
+            self.db_undo.put(b'reorg_limit', repr(self.reorg_limit).encode("utf-8"))
         # compute root hash
-        root_node = self.get_node('')
-        self.root_hash, coins = root_node.get_hash('', None)
+        root_node = self.get_node(b'')
+        self.root_hash, coins = root_node.get_hash(b'', None)
         # print stuff
         print_log("Database version %d."%db_version)
         print_log("Pruning limit for spent outputs is %d."%self.pruning_limit)
@@ -328,14 +328,14 @@ def get_address(self, txi):
         return self.db_addr.get(txi)
 
     def get_undo_info(self, height):
-        s = self.db_undo.get("undo_info_%d" % (height % self.reorg_limit))
+        s = self.db_undo.get(b"undo_info_%d" % (height % self.reorg_limit))
         if s is None:
             print_log("no undo info for ", height)
         return eval(s)
 
     def write_undo_info(self, height, bitcoind_height, undo_info):
         if height > bitcoind_height - self.reorg_limit or self.test_reorgs:
-            self.db_undo.put("undo_info_%d" % (height % self.reorg_limit), repr(undo_info))
+            self.db_undo.put(b"undo_info_%d" % (height % self.reorg_limit), repr(undo_info).encode("utf-8"))
 
     @staticmethod
     def common_prefix(word1, word2):
@@ -572,7 +572,7 @@ def close(self):
             db.close()
 
     def save_height(self, block_hash, block_height):
-        self.db_undo.put('height', repr((block_hash, block_height, DB_VERSION)))
+        self.db_undo.put(b'height', repr((block_hash, block_height, DB_VERSION)).encode("utf-8"))
 
     def add_to_history(self, addr, tx_hash, tx_pos, value, tx_height):
         key = self.address_to_key(addr)

From 7f6525a8d21eea98c231fdb197e8471f87ce9d41 Mon Sep 17 00:00:00 2001
From: Justin Turner Arthur <justinarthur@gmail.com>
Date: Sat, 17 Dec 2016 21:37:06 -0600
Subject: [PATCH 17/18] Communication with bitcoind to ported to Python 3.
 Mostly hex conversion and working with bytes.

---
 src/blockchain_processor.py | 54 +++++++++++++++++++++----------------
 src/utils.py                |  3 +++
 2 files changed, 34 insertions(+), 23 deletions(-)

diff --git a/src/blockchain_processor.py b/src/blockchain_processor.py
index 35311d82..2006fc37 100644
--- a/src/blockchain_processor.py
+++ b/src/blockchain_processor.py
@@ -21,6 +21,7 @@
 # CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 # SOFTWARE.
 
+from binascii import hexlify, unhexlify
 import hashlib
 from json import dumps, load
 import os
@@ -35,7 +36,7 @@
 from .processor import Processor, print_log
 from .storage import Storage
 from .utils import logger, hash_decode, hash_encode, Hash, header_from_string, header_to_string, ProfiledThread, \
-    rev_hex, int_to_hex4
+    rev_hex, int_to_hex4, utf8_reader
 
 class BlockchainProcessor(Processor):
 
@@ -60,7 +61,7 @@ def __init__(self, config, shared):
         self.max_cache_size = 100000
         self.chunk_cache = {}
         self.cache_lock = threading.Lock()
-        self.headers_data = ''
+        self.headers_data = b''
         self.headers_path = config.get('leveldb', 'path')
 
         self.mempool_fees = {}
@@ -79,12 +80,19 @@ def __init__(self, config, shared):
             self.test_reorgs = False
         self.storage = Storage(config, shared, self.test_reorgs)
 
-        self.bitcoind_url = 'http://%s:%s@%s:%s/' % (
-            config.get('bitcoind', 'bitcoind_user'),
-            config.get('bitcoind', 'bitcoind_password'),
+        self.bitcoind_url = 'http://%s:%s/' % (
             config.get('bitcoind', 'bitcoind_host'),
             config.get('bitcoind', 'bitcoind_port'))
 
+        bitcoind_passwd_mgr = urllib.request.HTTPPasswordMgrWithDefaultRealm()
+        bitcoind_passwd_mgr.add_password(
+            None,
+            self.bitcoind_url,
+            config.get('bitcoind', 'bitcoind_user'),
+            config.get('bitcoind', 'bitcoind_password')
+        )
+        bitcoind_auth_handler = urllib.request.HTTPBasicAuthHandler(bitcoind_passwd_mgr)
+        self.bitcoind_opener = urllib.request.build_opener(bitcoind_auth_handler)
         self.sent_height = 0
         self.sent_header = None
 
@@ -102,7 +110,7 @@ def __init__(self, config, shared):
 
     def do_catch_up(self):
         self.header = self.block2header(self.bitcoind('getblock', (self.storage.last_hash,)))
-        self.header['utxo_root'] = self.storage.get_root_hash().encode('hex')
+        self.header['utxo_root'] = hexlify(self.storage.get_root_hash())
         self.catch_up(sync=False)
         if not self.shared.stopped():
             print_log("Blockchain is up to date.")
@@ -132,7 +140,7 @@ def print_time(self, num_tx):
         if self.storage.height%100 == 0 \
             or (self.storage.height%10 == 0 and self.storage.height >= 100000)\
             or self.storage.height >= 200000:
-            msg = "block %d (%d %.2fs) %s" %(self.storage.height, num_tx, delta, self.storage.get_root_hash().encode('hex'))
+            msg = "block %d (%d %.2fs) %s" %(self.storage.height, num_tx, delta, hexlify(self.storage.get_root_hash()))
             msg += " (%.2ftx/s, %.2fs/block)" % (tx_per_second, seconds_per_block)
             run_blocks = self.storage.height - self.start_catchup_height
             remaining_blocks = self.bitcoind_height - self.storage.height
@@ -156,8 +164,8 @@ def bitcoind(self, method, params=()):
         postdata = dumps({"method": method, 'params': params, 'id': 'jsonrpc'})
         while True:
             try:
-                response = urllib.request.urlopen(self.bitcoind_url, postdata)
-                r = load(response)
+                response = self.bitcoind_opener.open(self.bitcoind_url, postdata.encode("utf-8"))
+                r = load(utf8_reader(response))
                 response.close()
             except:
                 print_log("cannot reach bitcoind...")
@@ -193,7 +201,7 @@ def init_headers(self, db_height):
         self.headers_filename = os.path.join(self.headers_path, 'blockchain_headers')
 
         if os.path.exists(self.headers_filename):
-            height = os.path.getsize(self.headers_filename)/80 - 1   # the current height
+            height = os.path.getsize(self.headers_filename)//80 - 1   # the current height
             if height > 0:
                 prev_hash = self.hash_header(self.read_header(height))
             else:
@@ -231,7 +239,7 @@ def init_headers(self, db_height):
 
     @staticmethod
     def hash_header(header):
-        return rev_hex(Hash(header_to_string(header).decode('hex')).encode('hex'))
+        return rev_hex(hexlify(Hash(unhexlify(header_to_string(header)))))
 
     def read_header(self, block_height):
         if os.path.exists(self.headers_filename):
@@ -246,13 +254,13 @@ def read_chunk(self, index):
         with open(self.headers_filename, 'rb') as f:
             f.seek(index*2016*80)
             chunk = f.read(2016*80)
-        return chunk.encode('hex')
+        return hexlify(chunk)
 
     def write_header(self, header, sync=True):
         if not self.headers_data:
             self.headers_offset = header.get('block_height')
 
-        self.headers_data += header_to_string(header).decode('hex')
+        self.headers_data += unhexlify(header_to_string(header))
         if sync or len(self.headers_data) > 40*100:
             self.flush_headers()
 
@@ -272,7 +280,7 @@ def flush_headers(self):
         with open(self.headers_filename, 'rb+') as f:
             f.seek(self.headers_offset*80)
             f.write(self.headers_data)
-        self.headers_data = ''
+        self.headers_data = b''
 
     def get_chunk(self, i):
         # store them on disk; store the current chunk in memory
@@ -291,7 +299,7 @@ def get_mempool_transaction(self, txid):
         except:
             return None
         vds = deserialize.BCDataStream()
-        vds.write(raw_tx.decode('hex'))
+        vds.write(unhexlify(raw_tx))
         try:
             return deserialize.parse_Transaction(vds, is_coinbase=False)
         except:
@@ -340,7 +348,7 @@ def get_status(self, addr, cache_only=False):
         if tx_points == ['*']:
             return '*'
         status = ''.join(tx.get('tx_hash') + ':%d:' % tx.get('height') for tx in tx_points)
-        return hashlib.sha256(status).digest().encode('hex')
+        return hexlify(hashlib.sha256(status).digest())
 
     def get_merkle(self, tx_hash, height, cache_only):
         with self.cache_lock:
@@ -389,9 +397,9 @@ def deserialize_block(block):
         txdict = {}     # deserialized tx
         is_coinbase = True
         for raw_tx in txlist:
-            tx_hash = hash_encode(Hash(raw_tx.decode('hex')))
+            tx_hash = hash_encode(Hash(unhexlify(raw_tx)))
             vds = deserialize.BCDataStream()
-            vds.write(raw_tx.decode('hex'))
+            vds.write(unhexlify(raw_tx))
             try:
                 tx = deserialize.parse_Transaction(vds, is_coinbase)
             except:
@@ -546,7 +554,7 @@ def process(self, request, cache_only=False):
         elif method == 'blockchain.utxo.get_address':
             txid = str(params[0])
             pos = int(params[1])
-            txi = (txid + int_to_hex4(pos)).decode('hex')
+            txi = unhexlify(txid + int_to_hex4(pos))
             result = self.storage.get_address(txi)
 
         elif method == 'blockchain.block.get_header':
@@ -621,8 +629,8 @@ def get_block(self, block_hash):
 
         while True:
             try:
-                response = urllib.request.urlopen(self.bitcoind_url, postdata)
-                r = load(response)
+                response = self.bitcoind_opener.open(self.bitcoind_url, postdata.encode("utf-8"))
+                r = load(utf8_reader(response))
                 response.close()
             except:
                 logger.error("bitcoind error (getfullblock)")
@@ -704,7 +712,7 @@ def catch_up(self, sync=True):
             self.print_time(n)
 
         self.header = self.block2header(self.bitcoind('getblock', (self.storage.last_hash,)))
-        self.header['utxo_root'] = self.storage.get_root_hash().encode('hex')
+        self.header['utxo_root'] = hexlify(self.storage.get_root_hash())
 
         if self.shared.stopped(): 
             print_log( "closing database" )
@@ -766,7 +774,7 @@ def memorypool_update(self):
                     addr, value = mpv[prev_n]
                     self.mempool_unconfirmed[tx_hash].add(prev_hash)
                 else:
-                    txi = (prev_hash + int_to_hex4(prev_n)).decode('hex')
+                    txi = unhexlify(prev_hash + int_to_hex4(prev_n))
                     try:
                         addr = self.storage.get_address(txi)
                         value = self.storage.get_utxo_value(addr,txi)
diff --git a/src/utils.py b/src/utils.py
index 81712321..ad7ba5a9 100644
--- a/src/utils.py
+++ b/src/utils.py
@@ -27,6 +27,7 @@
 import hashlib
 import struct
 from binascii import hexlify, unhexlify
+from codecs import getreader
 from collections import deque
 from itertools import repeat
 
@@ -99,6 +100,8 @@ def header_from_string(s):
     }
 
 
+utf8_reader = getreader("utf-8")
+
 ############ functions from pywallet #####################
 
 

From 6ae25eef1c80b8f4ead59dab8e05ac565ef57016 Mon Sep 17 00:00:00 2001
From: Justin Turner Arthur <justinarthur@gmail.com>
Date: Sat, 17 Dec 2016 21:38:36 -0600
Subject: [PATCH 18/18] Fixes to storage for Python 3's bytes vs Python 2's
 str.

---
 src/storage.py | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/src/storage.py b/src/storage.py
index 0bbc03c2..155fdda6 100644
--- a/src/storage.py
+++ b/src/storage.py
@@ -69,7 +69,7 @@ def is_singleton(self, key):
     def get_singleton(self):
         for i in range(256):
             if self.k == (1<<i):
-                return chr(i)
+                return bytes((i,))
         raise BaseException("get_singleton")
 
     def indexof(self, c):
@@ -131,9 +131,9 @@ def from_dict(klass, d):
         k = 0
         s = b''
         for i in range(256):
-            if chr(i) in d:
+            if i in d:
                 k += 1<<i
-                h, value = d[chr(i)]
+                h, value = d[i]
                 if h is None: h = b'\x00'*32
                 vv = int_to_bytes8(value)
                 item = h + vv
@@ -366,7 +366,7 @@ def add_key(self, target, value, height):
         parent = path[-1]
         parent_node = self.get_node(parent)
         n = len(parent)
-        c = target[n]
+        c = target[n:n+1]
         if parent_node.has(c):
             h, v = parent_node.get(c)
             skip = self.get_skip(parent + c)
@@ -389,8 +389,8 @@ def add_key(self, target, value, height):
                     target[index]: (None, 0),
                     child[index]: (h, v)
                     })
-            self.set_skip(prefix + target[index], target[index+1:])
-            self.set_skip(prefix + child[index], child[index+1:])
+            self.set_skip(prefix + target[index:index+1], target[index+1:])
+            self.set_skip(prefix + child[index:index+1], child[index+1:])
             self.put_node(prefix, d)
             path.append(prefix)
             self.parents[child] = prefix
@@ -434,14 +434,14 @@ def update_hashes(self):
 
                 node_hash, node_value = self.hash_list.pop(node)
 
-                parent = self.parents[node] if node!='' else ''
+                parent = self.parents[node] if node != b'' else b''
 
                 if i != KEYLENGTH and node_hash is None:
                     n = self.get_node(node)
                     node_hash, node_value = n.get_hash(node, parent)
                 assert node_hash is not None
 
-                if node == '':
+                if node == b'':
                     self.root_hash = node_hash
                     self.root_value = node_value
                     assert self.root_hash is not None
@@ -454,12 +454,12 @@ def update_hashes(self):
                     assert d is not None
 
                 # write value into parent
-                letter = node[len(parent)]
+                letter = node[len(parent):len(parent)+1]
                 d.set(letter, node_hash, node_value)
                 nodes[parent] = d
 
                 # iterate
-                grandparent = self.parents[parent] if parent != '' else None
+                grandparent = self.parents[parent] if parent != b'' else None
                 parent_hash, parent_value = d.get_hash(parent, grandparent)
                 if parent_hash is not None:
                     self.hash_list[parent] = (parent_hash, parent_value)
@@ -487,7 +487,7 @@ def get_path(self, target, new=False):
             return True
 
         remaining = target
-        key = ''
+        key = b''
         path = []
         while key != target:
             node = self.get_node(key)
@@ -495,7 +495,7 @@ def get_path(self, target, new=False):
                 break
                 #raise # should never happen
             path.append(key)
-            c = remaining[0]
+            c = remaining[0:1]
             if not node.has(c):
                 break
             skip = self.get_skip(key + c)
@@ -517,7 +517,7 @@ def delete_key(self, leaf):
             del self.hash_list[leaf]
 
         parent = path[-1]
-        letter = leaf[len(parent)]
+        letter = leaf[len(parent):len(parent)+1]
         parent_node = self.get_node(parent)
         parent_node.remove(letter)
 
@@ -535,7 +535,7 @@ def delete_key(self, leaf):
             # update skip value in grand-parent
             gp = path[-2]
             gp_items = self.get_node(gp)
-            letter = otherleaf[len(gp)]
+            letter = otherleaf[len(gp):len(gp)+1]
             new_skip = otherleaf[len(gp)+1:]
             gp_items.set(letter, None, 0)
             self.set_skip(gp+ letter, new_skip)
@@ -611,7 +611,7 @@ def set_spent(self, addr, txi, txid, index, height, undo):
         self.db_addr.delete(txi)
         # add to history
         s = self.db_hist.get(addr)
-        if s is None: s = ''
+        if s is None: s = b''
         txo = unhexlify(txid + int_to_hex4(index) + int_to_hex4(height))
         s += txi + int_to_bytes4(in_height) + txo
         s = s[ -80*self.pruning_limit:]