The browser (or proxy) sent a request that this server could not understand
异常原因:POST方法所需求的名字不在HTML里
e.g. <input name="title" type="text">entry_title = request.form['tit']
解决方案:名字保持一致
e.g.<input name="title" type="text">entry_title = request.form['title']
Method Not Allowed:The method is not allowed for the requested URL.
异常原因:HTML里 <form name="login" method="post"> post小写解决方案:POST大写
'form' is not define
异常原因:return render_template('index.html') 没传入form
解决方案:return render_template('index.html', form=form)