通过源码方式安装Python3.7之后pip功能异常，提示：

[root@localhost ~]# pip install httpbin
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Collecting httpbin
  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/httpbin/
  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/httpbin/
  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/httpbin/
  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/httpbin/
  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/httpbin/
  Could not fetch URL https://pypi.org/simple/httpbin/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.org', port=443): Max retries exceeded with url: /simple/httpbin/ (Caused by SSLError("Can't connect to HTTPS URL because the SSL module is not available.")) - skipping
  Could not find a version that satisfies the requirement httpbin (from versions: )
No matching distribution found for httpbin
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Could not fetch URL https://pypi.org/simple/pip/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.org', 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
[root@localhost ~]#

查阅资料之后发现：在./configure过程中，如果没有加上–with-ssl参数时，默认安装的软件涉及到ssl的功能不可用，
刚好pip3过程需要ssl模块，而由于没有指定，所以该功能不可用。

首先安装openssl-devel：

 yum -y install openssl-devel

然后重新编译安装，不过这一次除了指定安装位置之外请额外指定--with-ssl参数：

./configure --prefix=/usr/local/python3 --with-ssl

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参考：
python pip 出现locations that require TLS/SSL异常处理方法 https://blog.csdn.net/zhengcaihua0/article/details/79681991