##页面切换变动
<form action="{{url_for('server')}}" method="POST">
<div>
<label for="">用户名：</label>
<input type="text" name="username">
</div>
<div>
<label for="">密码：</label>
<input type="password" name="passwd">
</div>
<div>
<label for="">手机号码：</label>
<input type="text" name="tel">
</div>
<div>
<label for=""></label>
<input type="submit">
<input type="reset">
</div>
</form>
@app.route('/server', methods=['post'])
def server():
# print(request)
# print(request.args)
# print(request.args.get('username'))
#
# return 'get方式'
print(request)
print(request.form)
print(request.form.get('username'))
return 'form方式'
1.表单控件的action="{{url_for('server')}}" 连接模板要提交的数据地址
2.提交之后，页面转到"{{url_for('server')}}"
3."{{url_for('server')}}"的视图函数接收处理数据
4.表单属性method="POST" 与路由函数参数methods=['post']要保持一致
5.get方式request.args post方式request.form