【问题标题】：Python 2 do_POST http.server multipart/formdata to Python 3Python 2 do_POST http.server multipart/formdata 到 Python 3
【发布时间】：2016-05-21 20:38:47
【问题描述】：

问题：试图将讲师的 python 2 代码翻译成 python 3
具体问题：不能从 python 3 中的表单访问消息字段

Instructor's Code Snippet From Udacity Full-Stack Foundations Course

def do_POST(self):
            try:
                self.send_response(301)
                self.send_header('Content-type', 'text/html')
                self.end_headers()
                ctype, pdict = cgi.parse_header(
                    self.headers.getheader('content-type'))
                if ctype == 'multipart/form-data':
                    fields = cgi.parse_multipart(self.rfile, pdict)
                    messagecontent = fields.get('message')
                output = ""
                output += "<html><body>"
                output += " <h2> Okay, how about this: </h2>"
                output += "<h1> %s </h1>" % messagecontent[0]
                output += '''<form method='POST' enctype='multipart/form-data' action='/hello'><h2>What would you like me to say?</h2><input name="message" type="text" ><input type="submit" value="Submit"> </form>'''
                output += "</body></html>"
                self.wfile.write(output)
                print output
            except:
                pass

在查找文档、github 存储库、stackoverflow 帖子和花费无数小时后...我无法弄清楚如何在 python 3 中提取消息字段，如fields.get('message')。

我的尝试

def do_POST(self):
            try:
                length = int(self.headers['Content-Length'])
                print(self.headers['Content-Type'])
                self.send_response(301)
                self.send_header('Content-type', 'text/html')
                self.end_headers()
                post_data = parse_qs(self.rfile.read(length).decode('utf-8'))
                self.wfile.write("Lorem Ipsum".encode("utf-8"))
                ctype, pdict = cgi.parse_header(self.headers.getheader('content-type'))
                if ctype == 'multipart/form-data':
                    fields = cgi.parse_multipart(self.rfile, pdict)
                    messagecontent = fields.get('message')
    
                output = ''
                output += '<html><body>'
                output += '<h2> Okay, how about this: </h2>'
                output += '<h1> %s </h1>' % messagecontent[0]
                # You now have a dictionary of the post data
    
    
                output += "<form method='POST' enctype='multipart/form-data' action='/hello'><h2>What would you like me to say?</h2><input name='message' type='text'><input type='submit' value='Submit'></form>"
                output += '</html></body>'
                self.wfile.write(output.encode('utf-8'))
    
            except:
                print('Error!')

我的 post_data 变量是一个字典，但我找不到一种方法来提取我在表单中输入的“嗨”消息。我也不确定这是否是从表单中提取数据的正确方法。

>>> post_data
{' name': ['"message"\r\n\r\nhi\r\n------WebKitFormBoundarygm0MsepKJXVrBubX--\r\n']}

【问题讨论】：

标签： python forms python-2.7 python-3.x http-post

【解决方案1】：

我的解决方案

def do_POST(self):
            try:
                length = int(self.headers['Content-Length'])
                self.send_response(301)
                self.send_header('Content-type', 'text/html')
                self.end_headers()
                post_data = parse_qs(self.rfile.read(length).decode('utf-8'))
                messagecontent = post_data.get(' name')[0].split('\n')[2]
                output = ''
                output += '<html><body>'
                output += '<h2> Okay, how about this: </h2>'
                output += '<h1> %s </h1>' % messagecontent
                output += "<form method='POST' enctype='multipart/form-data' action='/hello'><h2>What would you like me to say?</h2><input name='message' type='text'><input type='submit' value='Submit'></form>"
                output += '</html></body>'
                self.wfile.write(output.encode('utf-8'))
            except:
                pass

如果有更好的方法，我很想知道！不知道为什么我必须在post_data.get(' name') 的“名称”之前添加一个空格。但是，嘿！有效！

更新：终于弄明白了

def do_POST(self):
        self.send_response(301)
        self.send_header('Content-type', 'text/html')
        self.end_headers()
        ctype, pdict = cgi.parse_header(self.headers['Content-Type'])
        if ctype == 'multipart/form-data':
            pdict['boundary'] = bytes(pdict['boundary'], 'utf-8')
            fields = cgi.parse_multipart(self.rfile, pdict)
            messagecontent = fields.get('message')[0].decode('utf-8')
        output = ''
        output += '<html><body>'
        output += '<h2> Okay, how about this: </h2>'
        output += '<h1> %s </h1>' % messagecontent
        output += "<form method='POST' enctype='multipart/form-data' action='/hello'><h2>What would you like me to say?</h2><input name='message' type='text'><input type='submit' value='Submit'></form>"
        output += '</html></body>'
        self.wfile.write(output.encode('utf-8'))

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【讨论】：

你能解释一下为什么你创建了一个 pdict['boundary'] 并解释一下关于 Python3 更改的其他更改吗？

【解决方案2】：

在发布时（2019 年），我无法让您的代码正常工作。检查cgi模块，parse_multipart试图访问pdict['CONTENT-LENGHT']。

我的解决方案，工作@发布时间：

   def do_POST(self):
    try:
        self.send_response(301)
        self.send_header('Content-type', 'text/html')
        self.end_headers()
        # HEADERS are now in dict/json style container
        ctype, pdict = cgi.parse_header(
            self.headers.get('content-type'))
        # boundary data needs to be encoded in a binary format


        if ctype == 'multipart/form-data':
            pdict['boundary'] = bytes(pdict['boundary'], "utf-8")
            pdict['CONTENT-LENGTH'] = self.headers.get('content-length')
            fields = cgi.parse_multipart(self.rfile, pdict)
            messagecontent = fields.get('message')

        output = ""
        output += "<html><body>"
        output += " <h2> Okay, how about this: </h2>"
        # decode it back into a string rather than byte string(b'stuff')
        output += "<h1> {} </h1>".format(messagecontent[0])
        output += '''<form method='POST' enctype='multipart/form-data' action='/hello'><h2>What would you like me to say?</h2><input name="message" type="text" ><input type="submit" value="Submit"> </form>'''
        output += "</body></html>"
        self.wfile.write(output.encode())
        print(output)

    except:
        raise

【讨论】：