需白名单哪些URL以解决严格代理下pip安装openpyxl、PyPDF2的问题

要通过pip正常安装openpyxl和PyPDF2，需将以下核心URL加入代理白名单：

• https://pypi.org/：PyPI官方索引服务器，用于查询包的版本信息与下载路径
• https://files.pythonhosted.org/：PyPI的包文件存储节点，所有PyPI包的实际下载文件都托管在此

报错原因说明 #

你的报错是代理禁止了对PyPI索引路径的访问，导致pip无法查询到openpyxl的可用版本：

C:\Windows\system32>pip install openpyxl
WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', OSError('Tunnel connection failed: 403 Forbidden'))': /simple/openpyxl/
WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', OSError('Tunnel connection failed: 403 Forbidden'))': /simple/openpyxl/
WARNING: Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', OSError('Tunnel connection failed: 403 Forbidden'))': /simple/openpyxl/
WARNING: Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', OSError('Tunnel connection failed: 403 Forbidden'))': /simple/openpyxl/
WARNING: Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', OSError('Tunnel connection failed: 403 Forbidden'))': /simple/openpyxl/
ERROR: Could not find a version that satisfies the requirement openpyxl (from versions: none)
ERROR: No matching distribution found for openpyxl

将上述两个URL加入白名单后，pip就能正常查询包索引并下载openpyxl、PyPDF2及其依赖包。

内容的提问来源于stack exchange，提问作者Arek