Heroku上用于Python 3.4的损坏电子邮件模块

每当我在Heroku上执行导入flask应用程序模块的脚本时，它会抛出以下错误，即找不到email.Utils：

File "/app/mod/__init__.py", line 1, in <module>
from flask import Flask
File "/app/.heroku/python/lib/python3.4/site-packages/flask/__init__.py", line 17, in <module>
    from werkzeug.exceptions import abort
  File "/app/.heroku/python/lib/python3.4/site-packages/werkzeug/__init__.py", line 154, in <module>
    __import__('werkzeug.exceptions')
  File "/app/.heroku/python/lib/python3.4/site-packages/werkzeug/exceptions.py", line 71, in <module>
    from werkzeug.wrappers import Response
  File "/app/.heroku/python/lib/python3.4/site-packages/werkzeug/wrappers.py", line 26, in <module>
    from werkzeug.http import HTTP_STATUS_CODES, \
  File "/app/.heroku/python/lib/python3.4/site-packages/werkzeug/http.py", line 24, in <module>
    from email.Utils import parsedate_tz
ImportError: No module named 'email.Utils'

---

没有Utils或Utils。这是怎么回事？Thx

在本地安装的Python3.4中，它是

email.utils

而不是

utils

werkzeug/http.py尝试这两种变体

email.utils

和

email.utils

都不存在。

>>> import email
>>> email.__file__
'/app/.heroku/python/lib/python3.4/email/__init__.py'
>>> dir(email)
['__all__', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__path__', '__spec__', '__version__', 'message_from_binary_file', 'message_from_bytes', 'message_from_file', 'message_from_string']