pip install安装报错

pip install PrettyTable报错
1. 安装升级pip

wget https://bootstrap.pypa.io/pip/2.7/get-pip.py

python get-pip.py -i http://pypi.douban.com/simple –trusted-host pypi.douban.com

2. 安装PrettyTable

$ pip install PrettyTable
DEPRECATION: Python 2.7 reached the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 is no longer maintained. pip 21.0 will drop support for Python 2.7 in January 2021. More details about Python 2 support in pip can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support pip 21.0 will remove support for this functionality.
Defaulting to user installation because normal site-packages is not writeable
Looking in indexes: https://pypi.tuna.tsinghua.edu.cn/simple
WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by ‘SSLError(SSLError(1, u'[SSL: UNKNOWN_PROTOCOL] unknown protocol (_ssl.c:590)’),)’: /simple/prettytable/
WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by ‘SSLError(SSLError(1, u'[SSL: UNKNOWN_PROTOCOL] unknown protocol (_ssl.c:590)’),)’: /simple/prettytable/
WARNING: Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by ‘SSLError(SSLError(1, u'[SSL: UNKNOWN_PROTOCOL] unknown protocol (_ssl.c:590)’),)’: /simple/prettytable/
WARNING: Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by ‘SSLError(SSLError(1, u'[SSL: UNKNOWN_PROTOCOL] unknown protocol (_ssl.c:590)’),)’: /simple/prettytable/
WARNING: Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by ‘SSLError(SSLError(1, u'[SSL: UNKNOWN_PROTOCOL] unknown protocol (_ssl.c:590)’),)’: /simple/prettytable/
Could not fetch URL https://pypi.tuna.tsinghua.edu.cn/simple/prettytable/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host=’pypi.tuna.tsinghua.edu.cn’, port=443): Max retries exceeded with url: /simple/prettytable/ (Caused by SSLError(SSLError(1, u'[SSL: UNKNOWN_PROTOCOL] unknown protocol (_ssl.c:590)’),)) – skipping
ERROR: Could not find a version that satisfies the requirement PrettyTable (from versions: none)
ERROR: No matching distribution found for PrettyTable

如果遇到上述错误提示，记得使用如下命令更换源进行安装

pip install PrettyTable -i http://pypi.douban.com/simple –trusted-host pypi.douban.com