如何在Flask中将unicode头转换为字节字符串？

Question

我有一个Flask应用程序，已经在我的开发服务器上成功运行了。但是，当我尝试在mod_wsgi下运行同样的应用时，出现了一个错误：

TypeError: expected byte string object for header name, value of type unicode found

我尝试了很多种方法来转换请求头，但还是遇到同样的错误：

for k,v in dict(request.headers).iteritems():
    response.headers[k.encode('latin-1')] = v.encode('latin-1')

我还尝试了以下方法，但结果还是一样的错误：

.encode('utf-8'), decode('utf-8'), decode('latin-1'), str()

我是不是做错了什么？

编辑（我认为这是实际的错误追踪信息...）：

[Wed Mar 12 23:26:49 2014] [notice] Apache/2.2.25 (Unix) mod_wsgi/3.4 Python/2.7.5 configured -- resuming normal operations
[Wed Mar 12 23:26:49 2014] [info] Server built: Sep  9 2013 06:59:27
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524834): Starting process 'api' with threads=1.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524834): Initializing Python.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524835): Starting process 'api' with threads=1.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524835): Initializing Python.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524833): Starting process 'api' with threads=1.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524833): Initializing Python.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524832): Starting process 'api' with threads=1.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524832): Initializing Python.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524831): Starting process 'api' with threads=1.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524831): Initializing Python.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524833): Attach interpreter ''.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524833): Adding '/path/to/api/lib/python2.7' to path.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524834): Attach interpreter ''.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524834): Adding '/path/to/api/lib/python2.7' to path.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524832): Attach interpreter ''.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524832): Adding '/path/to/api/lib/python2.7' to path.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524835): Attach interpreter ''.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524835): Adding '/path/to/api/lib/python2.7' to path.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524831): Attach interpreter ''.
[Wed Mar 12 23:26:49 2014] [info] mod_wsgi (pid=524831): Adding '/path/to/api/lib/python2.7' to path.
[Wed Mar 12 23:26:51 2014] [info] mod_wsgi (pid=524833): Create interpreter 'web23.webfaction.com|'.
[Wed Mar 12 23:26:51 2014] [info] mod_wsgi (pid=524833): Adding '/path/to/api/lib/python2.7' to path.
[Wed Mar 12 23:26:51 2014] [info] [client 127.0.0.1] mod_wsgi (pid=524833, process='api', application='web23.webfaction.com|'): Loading WSGI script '/path/to/api/wsgi.py'.
[Wed Mar 12 23:26:52 2014] [error] [client 127.0.0.1] mod_wsgi (pid=524833): Exception occurred processing WSGI script '/path/to/api/wsgi.py'.
[Wed Mar 12 23:26:52 2014] [error] [client 127.0.0.1] TypeError: expected byte string object for header name, value of type unicode found

编辑 #2：这是我在Flask中尝试获取令牌的视图，以及我如何修改请求头（或者说，我至少是想这么做）：

@app.route('/oauth/token/', methods=['GET','POST'],subdomain='api')
@oauth.token_handler # e.g. the decorator for OAuthlib/OAuthlib-Flask
def access_token():
  return None

@app.after_request
def after(response):
  import urllib
  for k,v in dict(request.headers).iteritems():
    response.headers[urllib.quote(k)] = urllib.quote(v)

  return response

编辑 #3（来自“print dict(request.headers).items()”的输出）：

[('Forwarded-Request-Uri', u'/oauth/token?client_secret=rDRzy2Qgt627dZK6eFtnylluOad7PRuLNUBothIpb0KQWJmOBl&grant_type=client_credentials&client_id=lryd8PqzlSObOQNUUEgEjqKYIeCnnkifs1s16NZ1'), ('Accept-Encoding', u'gzip, deflate, compress'), ('X-Forwarded-Host', u'api.example.com'), ('X-Forwarded-For', u'917.85.235.27'), ('Http-X-Forwarded-Proto', u'https'), ('Host', u'api.example.com'), ('Accept', u'*/*'), ('User-Agent', u'python-requests/2.2.1 CPython/2.7.5+ Linux/3.11.0-12-generic'), ('Connection', u'close'), ('X-Forwarded-Proto', u'https'), ('Https', u'on'), ('X-Forwarded-Server', u'api.example.com'), ('X-Forwarded-Ssl', u'on')]

Answer 1

它工作了!

file = request.files.get('fileupload')

file = StringIO(file.read().decode("ISO-8859-1"))

Answer 2

我在这个问题上卡了很久，完全不满意选中的答案。下面是我在实际工作中用的解决方案。

@app.after_request
def after(response):
    new_resp_headers = {}
    for k, v in response.headers.items():
        new_resp_headers[k.encode('ISO-8859-1')] = v.encode('ISO-8859-1')
    response.headers = new_resp_headers
    return response

Answer 3

那怎么样呢

bytes(whatever_unicode.encode("utf-8"))

或者根据J.F. Sebastian的评论

some_unicode.encode("ISO-8859-1")

或者也许

import urllib
urllib.quote(unicode_string)

其中一个应该能行……我觉得