使用pip指令安装包，报错如下：
WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: WRONG_VERSION_NUMBER] wrong version number (_ssl.c:1123)'))': /simple/xlrd/
WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: WRONG_VERSION_NUMBER] wrong version number (_ssl.c:1123)'))': /simple/xlrd/
WARNING: Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: WRONG_VERSION_NUMBER] wrong version number (_ssl.c:1123)'))': /simple/xlrd/
WARNING: Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: WRONG_VERSION_NUMBER] wrong version number (_ssl.c:1123)'))': /simple/xlrd/
WARNING: Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: WRONG_VERSION_NUMBER] wrong version number (_ssl.c:1123)'))': /simple/xlrd/
Could not fetch URL https://pypi.org/simple/xlrd/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.org', port=443): Max retries exceeded with url: /simple/xlrd/ (Caused by SSLError(SSLError(1, '[SSL: WRONG_VERSION_NUMBER] wrong version number (_ssl.c:1123)'))) - skipping
ERROR: Could not find a version that satisfies the requirement xlrd
ERROR: No matching distribution found for xlrd
如图所示：
找了很多资料，最后解决方案如下：
1.创建pip文件夹
2.在pip文件夹下创建pip.ini
pip.ini内容如下，可直接复制：
[global]
index-url=http://mirrors.aliyun.com/pypi/simple
[install]
trusted-host=mirrors.aliyun.com
3.配置CLASSPATH系统环境变量：;%HOMEPATH%\pip\pip.in
4.再次使用pip install XXX安装，成功！
