Cleaner PYPY flag (platform module); Comment fixes

IPython/lib/pretty.py

@@ -632,7 +632,7 b' def _super_pprint(obj, p, cycle):'
     p.pretty(obj.__thisclass__)
     p.text(',')
     p.breakable()
-    if PYPY: # In PyPy, super() objects doesn't have __self__ attributes
+    if PYPY: # In PyPy, super() objects don't have __self__ attributes
         dself = obj.__repr__.__self__
         p.pretty(None if dself is obj else dself)
     else:

IPython/utils/py3compat.py

@@ -6,6 +6,7 b' import sys'
 import re
 import shutil
 import types
+import platform
 
 from .encoding import DEFAULT_ENCODING
 
@@ -292,7 +293,7 b' else:'
 
 
 PY2 = not PY3
-PYPY = any(k.startswith("pypy") for k in dir(sys))
+PYPY = platform.python_implementation() == "PyPy"
 
 
 def annotate(**kwargs):

tox.ini

@@ -5,7 +5,7 b''
 ;  -- Commands --
 ; pip install tox  # Installs tox
 ; tox              # Runs the tests (call from the directory with tox.ini)
-; tox -r           # Runs rebuilding virtual environments
+; tox -r           # Ditto, but forcing the virtual environments to be rebuilt
 ; tox -e py35,pypy # Runs only in the selected environments
 ; tox -- --all -j  # Runs "iptest --all -j" in every environment
 
@@ -22,7 +22,7 b' deps ='
   py{36,35,34,33,27}: matplotlib
   .[test]
 
-; It's just to avoid loading IPython module in the current directory
+; It's just to avoid loading the IPython package in the current directory
 changedir = {envtmpdir}
 
 commands = iptest {posargs}