Add ETF support for Python 3.x (#68)

* Added ETF support for Python 3.x
Bumped requirements for PyNaCl and youtube-dl

* Changed setup.py check from using six to sys
Bumped requirements for youtube-dl and websocket-client

.gitignore

@@ -4,8 +4,10 @@ disco*.egg-info/
 storage.db
 storage.json
 *.dca
+*.pyc
 .eggs/
 .cache/
+.benchmarks/
 __pycache__
 
 # Documentation stuff
@@ -13,3 +15,6 @@ docs/api/
 docs/_build
 _book/
 node_modules/
+
+# JetBrains IDE
+.idea/

README.md

@@ -15,7 +15,7 @@ Disco was built to run both as a generic-use library, and a standalone bot toolk
 |----|------|
 |requests[security]|adds packages for a proper SSL implementation|
 |ujson|faster json parser, improves performance|
-|erlpack|ETF parser, only Python 2.x, run with the --encoder=etf flag|
+|erlpack (2.x), earl-etf (3.x)|ETF parser run with the --encoder=etf flag|
 |gipc|Gevent IPC, required for autosharding|
 
 ## Examples

disco/gateway/encoding/etf.py

@@ -1,8 +1,13 @@
+import six
 from websocket import ABNF
-from erlpack import unpack, pack
 
 from disco.gateway.encoding.base import BaseEncoder
 
+if six.PY3:
+    from earl import unpack, pack
+else:
+    from erlpack import unpack, pack
+
 
 class ETFEncoder(BaseEncoder):
     TYPE = 'etf'
@@ -14,4 +19,6 @@ class ETFEncoder(BaseEncoder):
 
     @staticmethod
     def decode(obj):
+        if six.PY3:
+            return unpack(obj, encoding='utf-8', encode_binary_ext=True)
         return unpack(obj)

setup.py

@@ -1,8 +1,8 @@
+import sys
 from setuptools import setup, find_packages
 
 from disco import VERSION
 
-
 with open('requirements.txt') as f:
     requirements = f.readlines()
 
@@ -14,7 +14,7 @@ extras_require = {
     'http': ['flask==0.12.2'],
     'yaml': ['pyyaml==3.12'],
     'music': ['youtube_dl>=2018.1.14'],
-    'performance': ['erlpack==0.3.2', 'ujson==1.35'],
+    'performance': ['erlpack==0.3.2' if sys.version_info.major == 2 else 'earl-etf==2.1.2', 'ujson==1.35'],
     'sharding': ['gipc==0.6.0'],
     'docs': ['biblio==0.0.4'],
 }