tweaks to use subtree PLY master

setup.py

@@ -291,7 +291,7 @@ def main():
         url='https://github.com/xonsh/xonsh',
         platforms='Cross Platform',
         classifiers=['Programming Language :: Python :: 3'],
-        packages=['xonsh', 'xonsh.ply', 'xonsh.ptk', 'xonsh.parsers',
+        packages=['xonsh', 'xonsh.ply.ply', 'xonsh.ptk', 'xonsh.parsers',
                   'xonsh.xoreutils', 'xontrib',
                   'xonsh.completers', 'xonsh.prompt'],
         package_dir={'xonsh': 'xonsh', 'xontrib': 'xontrib'},

tests/test_lexer.py

@@ -12,7 +12,7 @@ import pytest
 try:
     from ply.lex import LexToken
 except ImportError:
-    from xonsh.ply.lex import LexToken
+    from xonsh.ply.ply.lex import LexToken
 
 
 from xonsh.lexer import Lexer

xonsh/lexer.py

@@ -9,7 +9,7 @@ import keyword as kwmod
 try:
     from ply.lex import LexToken
 except ImportError:
-    from xonsh.ply.lex import LexToken
+    from xonsh.ply.ply.lex import LexToken
 
 from xonsh.lazyasd import lazyobject
 from xonsh.platform import PYTHON_VERSION_INFO

xonsh/parsers/base.py

@@ -10,7 +10,7 @@ from collections import Iterable, Sequence, Mapping
 try:
     from ply import yacc
 except ImportError:
-    from xonsh.ply import yacc
+    from xonsh.ply.ply import yacc
 
 from xonsh import ast
 from xonsh.ast import has_elts, xonsh_call

xonsh/xonfig.py

@@ -13,7 +13,7 @@ import contextlib
 try:
     import ply
 except ImportError:
-    from xonsh import ply
+    from xonsh.ply import ply
 
 import xonsh.wizard as wiz
 from xonsh import __version__ as XONSH_VERSION