According document of 'What’s New In Python 3.7', 'async' are reserved keywords now.

Code in line 105 of 'odoo/addons/base/ir/ir_qweb/assetsbundle.py' 
`def to_html(self, sep=None, css=True, js=True, debug=False, async=False, url_for=(lambda url: url)):`
will throw SyntaxError out if we launch odoo with this update python.
odoo/tools/safe_eval.py
"""
safe_eval module - methods intended to provide more restricted alternatives to
                   evaluate simple and/or untrusted code.
Methods in this module are typically used as alternatives to eval() to parse
OpenERP domain strings, conditions and expressions, mostly based on locals
condition/math builtins.
"""
import dis
from opcode import HAVE_ARGUMENT, opmap, opname
import functools