pip issue installing almost any library

Question

I have a difficult time using pip to install almost anything. I'm new to coding, so I thought maybe this is something I've been doing wrong and have opted out to easy_install to get most of what I needed done, which has generally worked. However, now I'm trying to download the nltk library, and neither is getting the job done.

I tried entering

sudo pip install nltk

but got the following response:

/Library/Frameworks/Python.framework/Versions/2.7/bin/pip run on Sat May  4 00:15:38 2013
Downloading/unpacking nltk

  Getting page https://pypi.python.org/simple/nltk/
  Could not fetch URL [need more reputation to post link]: There was a problem confirming the ssl certificate: <urlopen error [Errno 1] _ssl.c:504: error:0D0890A1:asn1 encoding routines:ASN1_verify:unknown message digest algorithm>

  Will skip URL [need more reputation to post link]/simple/nltk/ when looking for download links for nltk

  Getting page [need more reputation to post link]/simple/
  Could not fetch URL https://pypi.python. org/simple/: There was a problem confirming the ssl certificate: <urlopen error [Errno 1] _ssl.c:504: error:0D0890A1:asn1 encoding routines:ASN1_verify:unknown message digest algorithm>

  Will skip URL [need more reputation to post link] when looking for download links for nltk

  Cannot fetch index base URL [need more reputation to post link]

  URLs to search for versions for nltk:
  * [need more reputation to post link]
  Getting page [need more reputation to post link]
  Could not fetch URL [need more reputation to post link]: There was a problem confirming the ssl certificate: <urlopen error [Errno 1] _ssl.c:504: error:0D0890A1:asn1 encoding routines:ASN1_verify:unknown message digest algorithm>

  Will skip URL [need more reputation to post link] when looking for download links for nltk

  Could not find any downloads that satisfy the requirement nltk

No distributions at all found for nltk

Exception information:
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pip-1.3.1-py2.7.egg/pip/basecommand.py", line 139, in main
    status = self.run(options, args)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pip-1.3.1-py2.7.egg/pip/commands/install.py", line 266, in run
    requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundle=self.bundle)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pip-1.3.1-py2.7.egg/pip/req.py", line 1026, in prepare_files
    url = finder.find_requirement(req_to_install, upgrade=self.upgrade)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pip-1.3.1-py2.7.egg/pip/index.py", line 171, in find_requirement
    raise DistributionNotFound('No distributions at all found for %s' % req)
DistributionNotFound: No distributions at all found for nltk

--easy_install installed fragments of the library and the code ran into trouble very quickly upon trying to run it.

Any thoughts on this issue? I'd really appreciate some feedback on how I can either get pip working or something to get around the issue in the meantime.

Answer 1

If you're connecting through a proxy, execute export https_proxy=<your_proxy> (on Unix or Git Bash) and then retry installation.

If you're using Windows cmd, this changes to set https_proxy=<your_proxy>.

Answer 2

I used pip3 version 9.0.1 and was unable to install any packages recently via the commandpip3 install.

Mac os version: EI Captain 10.11.5.

python version: 3.5

I tried the command:

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

It didn't work for me.

So I uninstalled the older pip and installed the newest version10.0.0 by entering this:

python3 -m pip uninstall pip setuptools
curl https://bootstrap.pypa.io/get-pip.py | python3

Now my problem was solved. If you are using the python2, you can substitute the python3 with python. I hope it also works for you.

Answer 3

macOS Sierra 10.12.6. Wasn't able to install anything through pip (python installed through homebrew). All the answers above didn't work.

Eventually, upgrade from python 3.5 to 3.6 worked.

brew update
brew doctor #(in case you see such suggestion by brew)

then follow any additional suggestions by brew, i.e. overwrite link to python.

Answer 4

tried

pip --trusted-host pypi.python.org --trusted-host files.pythonhosted.org --trusted-host pypi.org install xxx 

and finally worked out, not quite understand why the domain pypi.python.org is changed.

Answer 5

As posted above by blackjar, the below lines worked for me

pip --trusted-host pypi.python.org --trusted-host files.pythonhosted.org --trusted-host pypi.org install xxx

You need to give all three --trusted-host options. I was trying with only the first one after looking at the answers but it didn't work for me like that.

Answer 6

I used pip version 9.0.1 and had the same issue, all the answers above didn't solve the problem, and I couldn't install python / pip with brew for other reasons.

Upgrading pip to 9.0.3 solved the problem. And because I couldn't upgrade pip with pip I downloaded the source and installed it manually.

1. Download the correct version of pip from - https://pypi.org/simple/pip/
2. sudo python3 pip-9.0.3.tar.gz - Install pip

Or you can install newer pip with:

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