wsgiref错误解决笔记 "write() argument must be a bytes instance"

　　错误提示：

C:UsersDmailAppDataLocalProgramsPythonPython37python.exe "E:/s9/day60/06 jinja2版web服务端示例.py"
我再8090等你哦...
Traceback (most recent call last):
  File "C:UsersDmailAppDataLocalProgramsPythonPython37libwsgirefhandlers.py", line 138, in run
    self.finish_response()
  File "C:UsersDmailAppDataLocalProgramsPythonPython37libwsgirefhandlers.py", line 184, in finish_response
    self.write(data)
  File "C:UsersDmailAppDataLocalProgramsPythonPython37libwsgirefhandlers.py", line 279, in write
    "write() argument must be a bytes instance"
AssertionError: write() argument must be a bytes instance
127.0.0.1 - - [29/Sep/2019 13:13:30] "GET /index/ HTTP/1.1" 500 59
127.0.0.1 - - [29/Sep/2019 13:13:30] "GET /favicon.ico HTTP/1.1" 200 14

　　错误代码：

from wsgiref.simple_server import make_server
from jinja2 import Template

def index():
    with open('06jinja2版web框架.html','r',encoding='utf-8')as f:
        data = f.read()
    template = Template(data) # 生成模板文件
    ret = template.render({"name":"Dmail","hobby_list":['编程','大宝剑']}) #把数据填充到模板里面
    return [ret.encode('utf-8'),]



url_func = [
    ('/index/',index)]

def run_server(environ,star_response):
    star_response('200 OK',[('Content-Type','text/html;charset=urf-8')])
    url = environ['PATH_INFO'] #取到用户输入的url
    #print(url)
    func = None
    for i in url_func:
        if i[0] == url:
            func = i[1]
            break
    if func:
        response = func()
    else:
        response = b'404 not found!'
    return response

if __name__ == '__main__':
    httpd = make_server('127.0.0.1',8090,run_server)
    print('我再8090等你哦...')
    httpd.serve_forever()

　　

run_server函数执行到
response = func():
...
return [ret.encode('utf-8'),]
得到的返回值是一个列表
发现返回值给错了，应该是给一个bytes
将最后给返回值的代码改成
return ret.encode('utf-8')
访问:127.0.0.1:8090/index/之后可以正常访问了，但还是会报错
再将
run_server函数里的return改一下
return [response,]
好了，可以正常访问了，而且没有报错。
修改后的代码：

from wsgiref.simple_server import make_server
from jinja2 import Template

def index():
    with open('06jinja2版web框架.html','r',encoding='utf-8')as f:
        data = f.read()
    template = Template(data) # 生成模板文件
    ret = template.render({"name":"Dmail","hobby_list":['编程','大宝剑']}) #把数据填充到模板里面
    return ret.encode('utf-8')


url_func = [
    ('/index/',index)]

def run_server(environ,star_response):
    star_response('200 OK',[('Content-Type','text/html;charset=urf-8')])
    url = environ['PATH_INFO'] #取到用户输入的url
    #print(url)
    func = None
    for i in url_func:
        if i[0] == url:
            func = i[1]
            break
    if func:
        response = func()
    else:
        response = b'404 not found!'
    return [response,]

if __name__ == '__main__':
    httpd = make_server('127.0.0.1',8090,run_server)
    print('我再8090等你哦...')
    httpd.serve_forever()

　　服务端日志：

C:UsersDmailAppDataLocalProgramsPythonPython37python.exe "E:/s9/day60/06 jinja2版web服务端示例.py"
我再8090等你哦...
127.0.0.1 - - [29/Sep/2019 13:27:37] "GET /index/ HTTP/1.1" 200 213
127.0.0.1 - - [29/Sep/2019 13:27:37] "GET /favicon.ico HTTP/1.1" 200 14
127.0.0.1 - - [29/Sep/2019 13:27:40] "GET /index/ HTTP/1.1" 200 213
127.0.0.1 - - [29/Sep/2019 13:27:40] "GET /favicon.ico HTTP/1.1" 200 14

　　PS：报错啥原因我也一脸懵逼，不太清楚，反正搜索谷歌，百度啊，修修改改就改好了。emmm，记个博客吧，怕以后遇到类似的错误。