尝试为Python 3安装scikit-learn时出现“无法获取索引库URL”错误消息

Question

I try to install scikit-learn for Python 3. I do it in the following way:

virtualenv model_env
source  model_env/bin/activate
pip3 install sklearn

As a result I get the following error message:

Downloading/unpacking sklearn
  Cannot fetch index base URL https://pypi.python.org/simple/
  Could not find any downloads that satisfy the requirement sklearn
Cleaning up...
No distributions at all found for sklearn

I had the same problem with pandas package and I have resolved it by using the following command:

sudo apt-get install python3-pandas

Unfortunately, the same approach does not work for the sklearn

sudo apt-get install python3-sklearn

ADDED

When I replace sklearn by scikit-learn , I have the same problem:

Downloading/unpacking scikit-learn
  Cannot fetch index base URL https://pypi.python.org/simple/
  Could not find any downloads that satisfy the requirement scikit-learn
Cleaning up...
No distributions at all found for scikit-learn

ADDED 2

As it has been recommended, I have try to use pip in combination with -vvv . Note that I use pip3 instead of pip . This is what I get as the result:

Downloading/unpacking scikit-learn
  Getting page https://pypi.python.org/simple/scikit-learn/
  Could not fetch URL https://pypi.python.org/simple/scikit-learn/: connection error: HTTPSConnectionPool(host='pypi.python.org', port=443): Max retries exceeded with url: /simple/scikit-learn/ (Caused by <class 'OSError'>: [Errno 101] Network is unreachable)
  Will skip URL https://pypi.python.org/simple/scikit-learn/ when looking for download links for scikit-learn
  Getting page https://pypi.python.org/simple/
  Could not fetch URL https://pypi.python.org/simple/: connection error: HTTPSConnectionPool(host='pypi.python.org', port=443): Max retries exceeded with url: /simple/ (Caused by <class 'OSError'>: [Errno 101] Network is unreachable)
  Will skip URL https://pypi.python.org/simple/ when looking for download links for scikit-learn
  Cannot fetch index base URL https://pypi.python.org/simple/
  URLs to search for versions for scikit-learn:
  * https://pypi.python.org/simple/scikit-learn/
  Getting page https://pypi.python.org/simple/scikit-learn/
  Could not fetch URL https://pypi.python.org/simple/scikit-learn/: connection error: HTTPSConnectionPool(host='pypi.python.org', port=443): Max retries exceeded with url: /simple/scikit-learn/ (Caused by <class 'OSError'>: [Errno 101] Network is unreachable)
  Will skip URL https://pypi.python.org/simple/scikit-learn/ when looking for download links for scikit-learn
  Could not find any downloads that satisfy the requirement scikit-learn
Cleaning up...
  Removing temporary dir /tmp/pip_build_root...
No distributions at all found for scikit-learn
Exception information:
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/pip/basecommand.py", line 122, in main
    status = self.run(options, args)
  File "/usr/lib/python3/dist-packages/pip/commands/install.py", line 278, in run
    requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundle=self.bundle)
  File "/usr/lib/python3/dist-packages/pip/req.py", line 1178, in prepare_files
    url = finder.find_requirement(req_to_install, upgrade=self.upgrade)
  File "/usr/lib/python3/dist-packages/pip/index.py", line 277, in find_requirement
    raise DistributionNotFound('No distributions at all found for %s' % req)
pip.exceptions.DistributionNotFound: No distributions at all found for scikit-learn

Storing debug log for failure in /home/rngorb/.pip/pip.log

Answer 1

尝试使用

pip3 install scikit-learn

Answer 2

First update your pip:

pip3 install --upgrade pip

Then install scikit-learn with arg "--user". Don't use sudo with pip as it will give problems:

pip install --user scikit-learn

Answer 3

也许您应该考虑使用Anaconda （默认情况下同时包含这两个软件包），并使用管理环境和软件包的工具简化生活

Answer 4

I could solve it with this command:

py -m pip install --user NAME_OF_THE_LIBRARY

It worked with- NumPy, SciPy, matplotlib, ipython, jupyter, pandas, sympy, nose and scikit-learn

Answer 5

If you want the convenience of Anaconda packages but the flexibility and minimalism of pip package management, I suggest you try miniconda .

Once you install miniconda (remembering to source ~/.bash_profile or source ~/.bashrc ), you can do this to setup your environment:

conda create -n myenv scikit-learn pip python=3

This will get you a conda env with sklearn and pip in case you want to install libraries that are not supported as a conda package. The pip runs inside the conda env.

Answer 6

Based on this answer for question Python pip error: “Cannot fetch index base URL https://pypi.python.org/simple/” I would try to reinstall (and upgrade) pip with easy_install

easy_install pip==8.1.2

I tried to reproduce your problem, and installing scikit-learn succeeded after pip install numpy and pip install scipy in a virtual environment created by pyenv-3.4.

Answer 7

if you have multiple version of Python, make sure that you are at the correct site-package path before install.

It was the case for me!!!

Answer 8

It works perfectly fine. Try to install sklearn in the global environment ie in the terminal directly. For Ubuntu 17.04 (+ latest versions) try-

sudo apt-get install python3-sklearn

Similarly, for pandas

sudo apt-get install python3-pandas