Python mechanize引发BrowserStateError

我有以下代码：

br = mechanize.Browser()
br._factory.is_html = True
br.form = mechanize._form.ParseString('<form method="post"</form>', 'http://localhost/post.php')[1]

br.form.new_control('text', 'test',{'value':'something'})
br.form.fixup()
br.submit()

br=mechanize.Browser（）
br.\u factory.is\u html=True
br.form=mechanize.\u form.ParseString（“显然，
mechanize
要求您有实际响应才能提交表单：

def viewing_html(self):
    """Return whether the current response contains HTML data."""
    if self._response is None:
        raise BrowserStateError("not viewing any document")
    return self._factory.is_html

（）