pip安装包时报错：Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by ‘SSLError(SSLError(1, u’[SSL: CERTIFICATE_VERIFY_FAILED]
原因是：安装源的问题
解决办法：加国内安装包源，如：-i http://pypi.douban.com/simple/ --trusted-host pypi.douban.com
pip install pytz -i http://pypi.douban.com/simple/ --trusted-host pypi.douban.com
Looking in indexes: http://pypi.douban.com/simple/
Collecting cabby
Downloading http://pypi.doubanio.com/packages/cb/73/740e363b5f55253befc55841a5296de3bdcab55c06a69157b882a4a96c97/cabby-0.1.20.tar.gz
Requirement already satisfied: six in c:\python27\lib\site-packages (from cabby) (1.11.0)
Collecting libtaxii>=1.1.111 (from cabby)
Downloading http://pypi.doubanio.com/packages/02/da/c629970a17ca916110da9333fd814240753e73bae7426a16a1d9b6e5d0a7/libtaxii-1.1.112-py2.py3-none-any.whl (128kB)
100% |████████████████████████████████| 133kB 2.6MB/s
Collecting colorlog (from cabby)
Downloading http://pypi.doubanio.com/packages/68/4d/892728b0c14547224f0ac40884e722a3d00cb54e7a146aea0b3186806c9e/colorlog-4.0.2-py2.py3-none-any.whl
Requirement already satisfied: pytz>=2017.2 in c:\python27\lib\site-packages (from cabby) (2018.9)
Collecting furl>=0.4.7 (from cabby)
Downloading http://pypi.doubanio.com/packages/bd/b6/302ecc007de38274509d6397300afd2e274aba7f1c3c0a165b5f1e1a836a/furl-2.0.0-py2.py3-none-any.whl
Requirement already satisfied: requests>=2.7.0 in c:\python27\lib\site-packages (from cabby) (2.19.1)
Collecting python-dateutil>=1.4.1 (from libtaxii>=1.1.111->cabby)
Downloading http://pypi.doubanio.com/packages/41/17/c62faccbfbd163c7f57f3844689e3a78bae1f403648a6afb1d0866d87fbb/python_dateutil-2.8.0-py2.py3-none-any.whl (226kB)
100% |████████████████████████████████| 235kB 2.6MB/s
Collecting lxml>=2.2.3 (from libtaxii>=1.1.111->cabby)
Downloading http://pypi.doubanio.com/packages/e2/70/8d8fd5dff0ee4c368332ef75f4113eecb5a9e2905742b88c95687e9bacfc/lxml-4.3.1-cp27-cp27m-win_amd64.whl (3.6MB)
100% |████████████████████████████████| 3.6MB 2.4MB/s
Collecting colorama; sys_platform == "win32" (from colorlog->cabby)
Downloading http://pypi.doubanio.com/packages/4f/a6/728666f39bfff1719fc94c481890b2106837da9318031f71a8424b662e12/colorama-0.4.1-py2.py3-none-any.whl
Collecting orderedmultidict>=1.0 (from furl>=0.4.7->cabby)
Downloading http://pypi.doubanio.com/packages/05/70/9f0a8867d4d98becf60dc5707e10b39930747ee914dae46414b69e33a266/orderedmultidict-1.0-py2.py3-none-any.whl
Requirement already satisfied: idna<2.8,>=2.5 in c:\python27\lib\site-packages (from requests>=2.7.0->cabby) (2.7)
Requirement already satisfied: certifi>=2017.4.17 in c:\python27\lib\site-packages (from requests>=2.7.0->cabby) (2018.4.16)
Requirement already satisfied: urllib3<1.24,>=1.21.1 in c:\python27\lib\site-packages (from requests>=2.7.0->cabby) (1.23)
Requirement already satisfied: chardet<3.1.0,>=3.0.2 in c:\python27\lib\site-packages (from requests>=2.7.0->cabby) (3.0.4)
Installing collected packages: python-dateutil, lxml, libtaxii, colorama, colorlog, orderedmultidict, furl, cabby
Running setup.py install for cabby ... done
Successfully installed cabby-0.1.20 colorama-0.4.1 colorlog-4.0.2 furl-2.0.0 libtaxii-1.1.112 lxml-4.3.1 orderedmultidict-1.0 python-dateutil-2.8.0