Python安裝軟件包出錯

轉載請註明文章出處：https://tlanyan.me/python-ins...

今天用pip安裝軟件包，死活安裝不上，出現如下錯誤：

Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.VerifiedHTTPSConnection object at 0x10f5a7748>: Failed to establish a new connection: [Errno 8] nodename nor servname provided, or not known')': /packages/5c/e0/be401c003291b56efc55aeba6a80ab790d3d4cece2778288d65323009420/pip-19.1.1-py2.py3-none-any.whl
  Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.VerifiedHTTPSConnection object at 0x10f5a7668>: Failed to establish a new connection: [Errno 8] nodename nor servname provided, or not known')': /packages/5c/e0/be401c003291b56efc55aeba6a80ab790d3d4cece2778288d65323009420/pip-19.1.1-py2.py3-none-any.whl
  Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.VerifiedHTTPSConnection object at 0x10f5a76a0>: Failed to establish a new connection: [Errno 8] nodename nor servname provided, or not known')': /packages/5c/e0/be401c003291b56efc55aeba6a80ab790d3d4cece2778288d65323009420/pip-19.1.1-py2.py3-none-any.whl
  Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.VerifiedHTTPSConnection object at 0x10f5a7860>: Failed to establish a new connection: [Errno 8] nodename nor servname provided, or not known')': /packages/5c/e0/be401c003291b56efc55aeba6a80ab790d3d4cece2778288d65323009420/pip-19.1.1-py2.py3-none-any.whl
  Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.VerifiedHTTPSConnection object at 0x10f5a7978>: Failed to establish a new connection: [Errno 8] nodename nor servname provided, or not known')': /packages/5c/e0/be401c003291b56efc55aeba6a80ab790d3d4cece2778288d65323009420/pip-19.1.1-py2.py3-none-any.whl

Could not install packages due to an EnvironmentError: HTTPSConnectionPool(host='files.pythonhosted.org', port=443): Max retries exceeded with url: /packages/5c/e0/be401c003291b56efc55aeba6a80ab790d3d4cece2778288d65323009420/pip-19.1.1-py2.py3-none-any.whl (Caused by NewConnectionError('<pip._vendor.urllib3.connection.VerifiedHTTPSConnection object at 0x10f5a7b00>: Failed to establish a new connection: [Errno 8] nodename nor servname provided, or not known'))

還以爲是特定軟件包的問題，很快發現升級pip也有問題。

網上找了一圈，把代理、vpn等都關了，問題依舊。仔細看錯誤的最後一行，看到有files.pythonhosted.org這個域名，心想難道這個域名掛了？

ping這個域名，竟然提示解析錯誤。於是登陸到境外的服務器上ping，解析正常。想到應該是dns解析問題，接着把dns換成了1.1.1.1和8.8.8.8，再次安裝，問題順利解決。