python-pip安裝模塊總是報ssl module in Python is not available的錯誤

pip安裝模塊總是報ssl module in Python is not available的錯誤

環境：centos 6.5 + python2.7.13
問題：使用pip安裝模塊，總是包pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available的錯誤。已知系統已經安裝openssl、openssl-devel、pyopenssl等模塊。請大神幫忙解答。

[root@www ~]# pip install six
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Collecting six
Could not fetch URL https://pypi.python.org/simple/six/: There was a problem confirming the ssl certificate: Can't connect to HTTPS URL because the SSL module is not available. - skipping
Could not find a version that satisfies the requirement six (from versions: )
No matching distribution found for six

最佳回答：

http://www.cnblogs.com/yuechaotian/archive/2013/06/03/3115472.html