Linux修改python源

在运行pip install selenium或者安装其他三方库的时候遇到如下报错：

Defaulting to user installation because normal site-packages is not writeable
WARNING: pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
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("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/selenium/
WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/selenium/
WARNING: Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/selenium/
WARNING: Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/selenium/
WARNING: Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/selenium/
Could not fetch URL https://pypi.tuna.tsinghua.edu.cn/simple/selenium/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.tuna.tsinghua.edu.cn', port=443): Max retries exceeded with url: /simple/selenium/ (Caused by SSLError("Can't connect to HTTPS URL because the SSL module is not available.")) - skipping
ERROR: Could not find a version that satisfies the requirement selenium (from versions: none)
ERROR: No matching distribution found for selenium
WARNING: pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Could not fetch URL https://pypi.tuna.tsinghua.edu.cn/simple/pip/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.tuna.tsinghua.edu.cn', port=443): Max retries exceeded with url: /simple/pip/ (Caused by SSLError("Can't connect to HTTPS URL because the SSL module is not available.")) - skipping
WARNING: There was an error checking the latest version of pip.

切换到阿里云

pip3 config set global.index-url http://mirrors.aliyun.com/pypi/simple/

就可以了

或者到根目录下~/.pip/pip.conf，没有就自己创建

pip.conf文件内容如下：

[global]
index-url = http://mirrors.aliyun.com/pypi/simple/

[install]
trusted-host = mirrors.aliyun.com