ImportError：安装 Pusher 后无法导入名称 certificate_transparency答案

【问题标题】：ImportError: cannot import name certificate_transparency after installing PusherImportError：安装 Pusher 后无法导入名称 certificate_transparency
【发布时间】：2019-03-11 08:10:42
【问题描述】：

我用virtualenv env 创建了一个virtualenv，然后（在采购env/bin/activate 之后）用pip 安装了pusher。但是，每当我尝试运行我的模块时，都会收到此错误：

Traceback (most recent call last):
  File "/home/proc-daemon/google_appengine/google/appengine/runtime/wsgi.py", line 240, in Handle
    handler = _config_handle.add_wsgi_middleware(self._LoadHandler())
  File "/home/proc-daemon/google_appengine/google/appengine/runtime/wsgi.py", line 299, in _LoadHandler
    handler, path, err = LoadObject(self._handler)
  File "/home/proc-daemon/google_appengine/google/appengine/runtime/wsgi.py", line 85, in LoadObject
    obj = __import__(path[0])
  File "/home/proc-daemon/supachat/supachat.py", line 31, in <module>
    ssl=True
  File "/home/proc-daemon/supachat/env/lib/python2.7/site-packages/pusher/pusher.py", line 52, in __init__
    json_encoder, json_decoder, backend, **backend_options)
  File "/home/proc-daemon/supachat/env/lib/python2.7/site-packages/pusher/pusher_client.py", line 34, in __init__
    json_encoder, json_decoder, backend, **backend_options)
  File "/home/proc-daemon/supachat/env/lib/python2.7/site-packages/pusher/client.py", line 20, in __init__
    from .requests import RequestsBackend
  File "/home/proc-daemon/supachat/env/lib/python2.7/site-packages/pusher/requests.py", line 17, in <module>
    import urllib3.contrib.pyopenssl
  File "/home/proc-daemon/supachat/env/lib/python2.7/site-packages/urllib3/contrib/pyopenssl.py", line 46, in <module>
    import OpenSSL.SSL
  File "/home/proc-daemon/supachat/env/lib/python2.7/site-packages/OpenSSL/__init__.py", line 8, in <module>
    from OpenSSL import crypto, SSL
  File "/home/proc-daemon/supachat/env/lib/python2.7/site-packages/OpenSSL/crypto.py", line 12, in <module>
    from cryptography import x509
  File "/home/proc-daemon/supachat/env/lib/python2.7/site-packages/cryptography/x509/__init__.py", line 7, in <module>
    from cryptography.x509 import certificate_transparency
ImportError: cannot import name certificate_transparency

正确安装了所有依赖项，并且ls env/lib/python2.7/site-packages/cryptography/x509 显示（以及其他）certificate_transparency.pyc（和.py）。

是否有其他我没有意识到的安装 pusher 的方法？

【问题讨论】：

你确定所有的依赖都安装成功了吗？
是的。 Successfully installed asn1crypto-0.24.0 certifi-2018.8.24 cffi-1.11.5 chardet-3.0.4 cryptography-2.3.1 enum34-1.1.6 idna-2.7 ipaddress-1.0.22 markdown-3.0.1 ndg-httpsclient-0.5.1 pusher-2.0.1 pyasn1-0.4.4 pycparser-2.19 pyopenssl-18.0.0 pytz-2018.5 requests-2.19.1 six-1.11.0 urllib3-1.23

标签： python python-2.7 pusher google-app-engine-python

【解决方案1】：

所以，这并没有解释问题，但解决了问题。

我使用了错误的后端。导入pusher.gae 并设置backend=pusher.gae.GAEBackend 解决了这个问题。

【讨论】：