chore(refactor): multiple changes/cleanups Simplify 'for x in [list val]; alist.append(x)' to 'alist = list([list val])'. Easier to read as copy of list. Also twice as fast although speed not an issue. Remove unneeded list() wrappers. Replace set(list comprehension) with set comprehension. Also add trailing ,'s to last element in tuples/lists. Add some noqa items for acceptable operations in context. Switch " ... \" ...\" ..." to: ' ... " ... " ...' to remove need to escape internal '"'. Change 'not x in y' to 'x not in y'.

try:
    from html import escape as html_escape_  # python 3

    def html_escape(string, quote=False):
        # html_escape under python 3 sets quote to true by default
        # make it python 2 compatible
        return html_escape_(string, quote=quote)
except ImportError:
    # python 2 fallback
    from cgi import escape as html_escape  # noqa: F401