python之如何在 python 中将用户输入从一个类传递到另一个类

我是编程新手，所以很可能我做错了，但这就是我正在尝试做的事情。

我正在尝试编写一个程序，该程序的表单在一个类中接受用户输入，然后将其传递给另一个类，但我不知道该怎么做。这是相关代码的片段(我将 * 放在用户名变量周围，这是我要传递的变量):

class MainHandler(webapp2.RequestHandler): 
  #this is in a form 
   def post(self): 
    ***username*** = self.request.get('username') 
 
  #if username and other info entered correctly, then it redirects user to a new page and the WelcomeHandler class, so how do I get the username into the "Welcome, " message below?: 
 
 
class WelcomeHandler(webapp2.RequestHandler): 
    def get(self): 
        self.response.out.write("Welcome, " + ***username***) 

编辑:这是我的全部代码，如果有帮助的话:

import webapp2 
import re 
import cgi 
 
form=""" 
 
<form method = "post">    
Signup 
<br> 
 
<table> 
    <tbody>             
      <tr><td><label>Username</label></td><td><input type="text" name = "username"  
 value="%(username)s"><div style="color: red">%(error)s</div> </td></tr> 
 
<br> 
     <tr><td> <label>Password</label></td><td><input type="password" name = "password"  
value="%(password)s"><div>TK TK TK</div></td></tr> 
 
<br> 
    <tr><td> <label> Verify password</label></td><td><input type="password" name =  
"verify" value="%(verify)s"><div> TK TK TK</div></td></tr> 
 
<br> 
    <tr><td> <label> Email(optional)</label></td><td><input type = "text" name = "email" 
 value ="%(email)s"><div> TK TK TK</div></td></tr> 
 
 </tbody> 
</table> 
<br> 
<br> 
<input type = "submit"> 
</form> 
""" 
 
 
def escape_html(s): 
    return cgi.escape(s, quote = True) 
 
def valid_username(username): 
    USER_RE = re.compile(r"^[a-zA-Z0-9_-]{3,20}$") 
    return USER_RE.match(username) 
 
def valid_password(password): 
    USER_RE = re.compile(r"^.{3,20}$") 
    return USER_RE.match(password) 
 
def verify_password(password, verify): 
    if verify == password: 
        return True 
    else: 
        return False 
 
def valid_email(email): 
    USER_RE = re.compile(r"^[\S]+@[\S]+\.[\S]+$") 
    return USER_RE.match(email) 
 
class MainHandler(webapp2.RequestHandler): 
    def write_form(self, error="", username="", password="", verify="", email=""): 
        self.response.out.write(form % {'error': error, "username":  
escape_html(username), "password": escape_html(password), "verify": escape_html(verify), 
 "email": escape_html(email)}) 
 
    def get(self): 
        self.write_form() 
 
 
    def post(self): 
        username = self.request.get('username') 
        password = self.request.get('password') 
        verify = self.request.get('verify') 
        email = self.request.get('email') 
 
        username_check = valid_username(username) 
        password_check = valid_password(password) 
        verify_check = verify_password(password, verify) 
        email_check = valid_email(email) 
 
        if not (username_check and password_check and verify_check): 
            self.write_form("That's not valid, you jive turkey", username, password,  
verify, email) 
        else: 
            self.redirect("/welcome") 
 
class WelcomeHandler(webapp2.RequestHandler): 
    def get(self): 
        self.response.out.write("Welcome, " + username) 
 
 
app = webapp2.WSGIApplication([ 
        ('/', MainHandler), 
        ('/welcome', WelcomeHandler)], debug=True) 

请您参考如下方法:

你不想这样做。这不仅仅是普通的基于类的编程:这些类中的每一个都代表从浏览器向您的服务器发出的请求。在类之间传递该数据意味着什么？

您真正想要做的是告诉浏览器重定向到您的 GET 处理程序。