我无法升级pip：无法获取URL https://pypi.python.org/simple/pip/：存在一个确认ssl证书的问题

Question

Trying to upgrade pip in my terminal. Here's my code:

(env) macbook-pro83:zappatest zorgan$ pip install --upgrade pip
Could not fetch URL https://pypi.python.org/simple/pip/: There was a problem confirming the ssl certificate: [SSL: TLSV1_ALERT_PROTOCOL_VERSION] tlsv1 alert protocol version (_ssl.c:645) - skipping
Requirement already up-to-date: pip in ./env/lib/python3.5/site-packages
You are using pip version 8.1.2, however version 10.0.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.

Any idea what the problem is? I also get the same error There was a problem confirming the ssl certificate when I perform pip install django .

Edit pip install --upgrade pip -vvv returns :

1 location(s) to search for versions of pip:
* https://pypi.python.org/simple/pip/
Getting page https://pypi.python.org/simple/pip/
Looking up "https://pypi.python.org/simple/pip/" in the cache
Returning cached "301 Moved Permanently" response (ignoring date and etag information)
Looking up "https://pypi.org/simple/pip/" in the cache
Current age based on date: 23811
Freshness lifetime from max-age: 600
Freshness lifetime from request max-age: 600
Starting new HTTPS connection (1): pypi.org
Could not fetch URL https://pypi.python.org/simple/pip/: There was a problem confirming the ssl certificate: [SSL: TLSV1_ALERT_PROTOCOL_VERSION] tlsv1 alert protocol version (_ssl.c:645) - skipping
Installed version (8.1.2) is most up-to-date (past versions: none)
Requirement already up-to-date: pip in ./env/lib/python3.5/site-packages
Cleaning up...
You are using pip version 8.1.2, however version 10.0.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.

Answer 1

可以通过以下命令对其进行修复（卸载并重新安装pip）：

curl https://bootstrap.pypa.io/get-pip.py | python

Answer 2

a. Check your system date and time and see whether it is correct.

b. If the 1st solution doesn't fix it try using a lower security method:

pip install --index-url=http://pypi.python.org/simple/linkchecker

This bypasses HTTPS and uses HTTP instead, try this workaround only if you are in a hurry.

c. Try downgrading pip to a version that does not use SSL verification by:

pip install pip==1.2.1

and then upgrade pip back again to the newer version by:

pip install --upgrade pip

d. If nothing of the above works, uninstall pip and reinstall it.

Answer 3

You can get more details about upgrade failed by using

$ pip install --upgrade pip -vvv

there will be more details help you debug it.

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Try

pip --trusted-host pypi.python.org install --upgrade pip

Maybe useful.

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Another solution:

$ pip install certifi

then run install.