def parse_expr(s):
iend, tree = ep.tokenTree(s, 0, len(s), 0)
print tree
#print "::::: ", ep.tokenTree2string(s,tree, 0)
print ep.tokenTree2string(s, tree, 0, indent=True)
ep.walkTree_2(s, tree, 0, checkVar, empty, checkFunc)
exit()
