Whenever I am trying to install any package using pip, I am getting this import error:

guru@guru-notebook:~$ pip3 install numpy
Traceback (most recent call last):
  File "/usr/bin/pip3", line 9, in <module>
    from pip import main
ImportError: cannot import name 'main'

guru@guru-notebook:~$ cat `which pip3`
#!/usr/bin/python3
# GENERATED BY DEBIAN

import sys

# Run the main entry point, similarly to how setuptools does it, but because
# we didn't install the actual entry point from setup.py, don't use the
# pkg_resources API.
from pip import main
if __name__ == '__main__':
    sys.exit(main())

It was working fine earlier, I am not sure why it is throwing this error. I have searched about this error, but can’t find anything to fix it.

Please let me know if you need any further detail, I will update my question.

You must have inadvertently upgraded your system pip (probably through something like sudo pip install pip --upgrade)

pip 10.x adjusts where its internals are situated. The pip3 command you’re seeing is one provided by your package maintainer (presumably debian based here?) and is not a file managed by pip.

You can read more about this on pip’s issue tracker

You’ll probably want to not upgrade your system pip and instead use a virtualenv.

To recover the pip3 binary you’ll need to sudo python3 -m pip uninstall pip && sudo apt install python3-pip --reinstall.

If you want to continue in “unsupported territory” (upgrading a system package outside of the system package manager), you can probably get away with python3 -m pip ... instead of pip3.

We can clear the error by modifying the pip file.

Check the location of the file:

$ which pip

path -> /usr/bin/pip

Go to that location(/usr/bin/pip) and open terminal

Enter: $ sudo nano pip

You can see:

import sys
from pip import main
if __name__ == '__main__':
     sys.exit(main())

Change to:

import sys
from pip import __main__
if __name__ == '__main__':
     sys.exit(__main__._main())

then ctrl + o write the changes and exit

Hope this will do!!

For Ubuntu family, Debian, Linux Mint users

Thanks to Anthony’s explanation above, you can retain your original system pip (in /usr/bin/ and dist-packages/) and remove the manually-installed pip (in ~/.local/) to resolve the conflict:

$ python3 -m pip uninstall pip

Ubuntu/Debian pip v8.1.1 (16.04) from python3-pip debian package (see$ pip3 -V) shows the same search results as the latest pip v10.0.1, and installs latest modules from PyPI just fine. It has a working pip command (already in the $PATH), plus the nice --user option patched-in by default since 2016. Looking at pip release notes, the newer versions are mostly about use-case specific bug fixes and certain new features, so not everyone has to rush upgrading pip just yet. And the new pip 10 can be deployed to Python virtualenvs, anyway.

But regardless of pips, your OS allows to quickly install common Python modules (including numpy) with APT, without the need for pip, for example:
$ sudo apt install python3-numpy python3-scipy (with system dependencies)
$ sudo apt install python3-pip (Debian-patched pip, slightly older but it doesn’t matter)

Quick apt syntax reminder (please see man apt for details):
$ sudo apt update (to resync Ubuntu package index files from up-to-date sources)
$ apt search <python-package-name> (full text-search on all available packages)
$ apt show <python-package-name> (displays the detailed package description)
$ sudo apt install <python-package-name>

Package names prefixed with python- are for Python 2; and prefixed with python3- are for Python 3 (e.g. python3-pandas). There are thousands, and they undergo integration testing within Debian and Ubuntu. Unless you seek to install at per-user level (pip install --user option) or within virtualenv/venv, apt could be what you needed. These system packages are accessible from virtual envs too, as virtualenv will gracefully fall back to using system libs on import if your envs don’t have given copies of modules. Your custom-installed (with pip --user) per-user modules in ~/.local/lib will override them too.

Note, since this is a system-wide installation, you’d rarely need to remove them (need to be mindful about OS dependencies). This is convenient for packages with many system dependencies (such as with scipy or matplotlib), as APT will keep track and provide all required system libs and C extensions, while with pip you have no such guarantees.

In fact, for system-wide Python packages (in contrast to per-user, home dir level, or lower), Ubuntu expects using the APT package manager (rather than sudo pip) to avoid breaking OS: sudo pip3 targets the very same /usr/lib/python3/dist-packages directory where APT stores OS-sensitive modules. Recent Debian/Ubuntu releases depend heavily on Python 3, so its pre-installed modules are managed by apt and shouldn’t be changed.

So if you use pip3 install command, please ensure that it runs in an isolated virtual dev environment, such as with virtualenv (sudo apt install python3-virtualenv), or with Python3 built-in (-m venv), or at a per-user level (--user pip option, default in Ubuntu-provided pip since 2016), but not system-wide (never sudo pip3!), because pip interferes with the operation of the APT package manager and may affect Ubuntu OS components when a system-used python module is unexpectedly changed. Good luck!

P. S. All the above is for the ‘ideal’ solution (Debian/Ubuntu way).

If you still want to use the new pip3 v10 exclusively, there are 3 quick workarounds:

• simply open a new bash session (a new terminal tab, or type bash) – and pip3 v10 becomes available (see pip3 -V). debian’s pip3 v8 remains installed but is broken; or
• the command $ hash -d pip3 && pip3 -V to refresh pip3 pathname in the $PATH. debian’s pip3 v8 remains installed but is broken; or
• the command $ sudo apt remove python3-pip && hash -d pip3 to uninstall debian’s pip3 v8 completely, in favor of your new pip3 v10.

Note: You will always need to add --user flag to any non-debian-provided pip, unless you are in a virtualenv! (it deploys python packages to ~/.local/, default in debian/ubuntu-provided python3-pip and python-pip since 2016). Your use of pip 10 system-wide, outside of virtualenv, is not really supported by Ubuntu/Debian. Never sudo pip3!

Further details:
https://github.com/pypa/pip/issues/5221#issuecomment-382069604
https://github.com/pypa/pip/issues/5240#issuecomment-381673100

resolved in one step only.

I too faced this issue, But this can be resolved simply by 1 command without bothering around and wasting time and i have tried it on multiple systems it’s the cleanest solution for this issue. And that’s:

For python3:- sudo python3 -m pip uninstall pip && sudo apt install python3-pip --reinstall.

By this , you can simply install packages using pip3. to check use pip3 --version.

For older versions, use : sudo python -m pip uninstall pip && sudo apt install python-pip --reinstall.

By this, now you can simply install packages using pip. to check use pip --version.

Use python -m pip install instead of pip install

Example:

python -m pip install --user somepackage
python3 -m pip install --user somepackage

The pip (resp. pip3) executable is provided by your distro (python-pip package on Ubuntu 16.04) and located at /usr/bin/pip.

Therefore, it is not kept up-to date with the pip package itself as you upgrade pip, and may break.

If you just use python -m pip directly, e.g. as in:

python -m pip install --user somepackage
python3 -m pip install --user somepackage

it goes through your Python path, finds the latest version of pip and executes that file.

It relies on the fact that file is executable through import, but that is a very standard type of interface, and therefore less likely to break than the hackier Debian script.

Then I recommend adding the following aliases to your .bashrc:

pip() ( python -m pip "$@" )
pip3() ( python3 -m pip "$@" )

The Ubuntu 18.04 /usr/bin/pip3 file does:

from pip import main

and presumably main was removed from pip at some point which is what broke things.

The breaking pip commit appears to be: 95bcf8c5f6394298035a7332c441868f3b0169f4 “Move all internal APIs to pip._internal” which went into pip 18.0.

Tested in Ubuntu 16.04 after an update from pip3 9.0.1 to 18.0.

pyenv

Ultimately however, for serious Python development I would just recommend that you install your own local Python with pyenv + virtualenv, which would also get around this Ubuntu bug: https://askubuntu.com/questions/682869/how-do-i-install-a-different-python-version-using-apt-get/1195153#1195153

You can resolve this issue by reinstalling pip.

Use one of the following command line commands to reinstall pip:

Python2:

python -m pip uninstall pip && sudo apt install python-pip --reinstall

Python3:

 python3 -m pip uninstall pip && sudo apt install python3-pip --reinstall

Check if pip has been cached on another path, to do so, call $ which pip and check that the path is different from the one prompted in the error, if that’s the case run:

$ hash -r

When the cache is clear, pip will be working again. reference: http://cheng.logdown.com/posts/2015/06/14/-usr-bin-pip-no-such-file-or-directory

I’m running on a system where I have sudo apt but no sudo pip. (And no su access.) I got myself into this same situation by following the advice from pip:

You are using pip version 8.1.1, however 18.0 is available. You should consider upgrading via the ‘pip install –upgrade pip’ command.

None of the other fixes worked for me, because I don’t have enough admin privileges. However, a few things stuck with me from reading up on this:

• I shouldn’t have done this. Sure, pip told me to. It lied.
• Using –user solves a lot of issues by focusing on the user-only directory.

So, I found this command line to work to revert me back to where I was. If you were using a different version than 8.1.1, you will obviously want to change that part of the line.

python -m pip install --force-reinstall pip==8.1.1 --user

That’s the only thing that worked for me, but it worked perfectly!

Recover with python3 -m pip install --user pip==9.0.1 (or the version that worked)

Same thing happened to me on Pixelbook using the new LXC (strech). This solution is very similar to the accepted one, with one subtle difference, whiched fixed pip3 for me.

sudo python3 -m pip install --upgrade pip

That bumped the version, and now it works as expected.

I found it here … Python.org: Ensure pip is up-to-date

I met the same problem on my Ubuntu 16.04 system. I managed to fix it by re-installing pip with the following command:

curl https://bootstrap.pypa.io/get-pip.py | sudo python3

The commands above didn’t work for me but those were very helpful:

sudo apt purge python3-pip
sudo rm -rf '/usr/lib/python3/dist-packages/pip'  
sudo apt install python3-pip
cd
cd .local/lib/python3/site-packages
sudo rm -rf pip*  
cd
cd .local/lib/python3.5/site-packages
sudo rm -rf pip*  
sudo pip3 install jupyter

In ubuntu 18.04.1 Bionic Beaver, you need to log out and log back in (restart not necessary) to get the proper environment.

$ sudo apt install python-pip

$ pip --version
pip 9.0.1 from /usr/lib/python2.7/dist-packages (python 2.7)

$ pip install --upgrade pip

$ pip --version
Traceback (most recent call last):
  File "/usr/bin/pip", line 9, in <module>
    from pip import main
ImportError: cannot import name main

$ exit
<login>

$ pip --version
pip 18.1 from /home/test/.local/lib/python2.7/site-packages/pip (python 2.7)

I use sudo apt remove python3-pip then pip works.

 ~ sudo pip install pip --upgrade
[sudo] password for sen: 
Traceback (most recent call last):
  File "/usr/bin/pip", line 9, in <module>
    from pip import main
ImportError: cannot import name 'main'
➜  ~ sudo apt remove python3-pip   
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libexpat1-dev libpython3-dev libpython3.5-dev python-pip-whl python3-dev python3-wheel
  python3.5-dev
Use 'sudo apt autoremove' to remove them.
The following packages will be REMOVED:
  python3-pip
0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
After this operation, 569 kB disk space will be freed.
Do you want to continue? [Y/n] y
(Reading database ... 215769 files and directories currently installed.)
Removing python3-pip (8.1.1-2ubuntu0.4) ...
Processing triggers for man-db (2.7.5-1) ...
➜  ~ pip

Usage:   
  pip <command> [options]

For Python version 2.7 @Anthony solution works perfect, by changing python3 to python as follows:

sudo python -m pip uninstall pip && sudo apt install python-pip --reinstall

What worked for me to fix the error with using pip3 was:

sudo cp -v /usr/local/bin/pip3 /usr/bin/pip3

Everything works:

 demon@UbuntuHP:~$ pip -V
 pip 10.0.1 from /usr/local/lib/python3.5/dist-packages/pip (python 3.5)

 demon@UbuntuHP:~$ pip2 -V
 pip 10.0.1 from /home/demon/.local/lib/python2.7/site-packages/pip (python 2.7)

 demon@UbuntuHP:~$ pip3 -V
 pip 10.0.1 from /usr/local/lib/python3.5/dist-packages/pip (python 3.5)

Maybe the new 10.0.1 version of pip doesn’t update the binary in /usr/bin ? (which seems it does not)

EDIT: the same issue occurs in Ubuntu 18.04. The best solution I’ve found is to symlink the pip binaries from /home/<user/.local/bin to /usr/local/bin or /usr/bin (depending on your preference), as follows:

ln -sv /home/<user>/.local/bin/pip /usr/local/bin/pip
ln -sv /home/<user>/.local/bin/pip2 /usr/local/bin/pip2
ln -sv /home/<user>/.local/bin/pip2.7 /usr/local/bin/pip2.7
ln -sv /home/<user>/.local/bin/pip3 /usr/local/bin/pip3
ln -sv /home/<user>/.local/bin/pip3.6 /usr/local/bin/pip3.6

NOTE: replace <user> with your current running user

The associated versions (latest) are in:

Version 3.6:

/home/demon/.local/lib/python3.6/site-packages/pip (python 3.6)

Version 2.7:

/home/demon/.local/lib/python2.7/site-packages/pip (python 2.7)

Trick and works too

sudo -H pip install lxml

I had this same error, but python -m pip was still working, so I fixed it with the nuclear option sudo python -m pip install --upgrade pip. It did it for me.

For what it’s worth, I had the problem with pip (not pip2 or pip3):

$ pip -V
Traceback (most recent call last):
  File "/usr/bin/pip", line 9, in <module>
    from pip import main
ImportError: cannot import name main

$ pip2 -V
pip 8.1.1 from /usr/lib/python2.7/dist-packages (python 2.7)

$ pip3 -V
pip 8.1.1 from /usr/lib/python3/dist-packages (python 3.5)

Somehow (I can’t remember how) I had python stuff installed in my ~/.local directory. After I removed the pip directory from there, pip started working again.

$ rm -rf /home/precor/.local/lib/python2.7/site-packages/pip
$ pip -V
pip 8.1.1 from /usr/lib/python2.7/dist-packages (python 2.7)

Is something wrong with the packages, when it generating de file /usr/bin/pip, you have to change the import:

from pip import main

to

from pip._internal import main

That solves the problem, I’m not sure why it generated, but it saids somthing in the following issue:

After pip 10 upgrade on pyenv “ImportError: cannot import name ‘main'”

You can try this:

sudo ln -sf $( type -P pip ) /usr/bin/pip

I also run into this problem when I wanted to upgrade system pip pip3 from 9.0.1 to 19.2.3.

After running pip3 install --upgrade pip, pip version becomes 19.2.3. But main() has been moved in pip._internal in the latest version, which leaves pip3 broken.

So in file /usr/bin/pip3, replace line 9: from pip import main with from pip._internal import main. The issue will be fixed, works the same for python2-pip. (Tested on Ubuntu 18.04 distribution)

According to @Vincent H.’s answer

Please run the following commands to do the fix. After running python3 -m pip install --upgrade pip, please run the following command.

hash -r pip

Source: https://github.com/pypa/pip/issues/5221

you can simply fix the pip and pip3 paths using update-alternatives

first thing you should check is your current $PATH run echo $PATH and see is you can find /usr/local/bin which is where pip3 and pip usually are

there is a change your system is looking here /bin/pip and /bin/pip3 so i will say fix the PATH by adding to your ~/.bash_profile file so it persists

export PATH=$PATH:/usr/local/bin and then check is its fixed with which pip and which pip3

if not then use update-alternatives to fix it finally

update-alternatives --install /bin/pip3 pip3 /usr/local/bin/pip3 30

and if you want to point pip to pip3 then

update-alternatives --install /bin/pip pip /usr/local/bin/pip3 30

This Worked for me !

hash -r pip # or hash -d pip

Now, uninstall the pip installed version and reinstall it using the following commands.

python -m pip uninstall pip  # sudo
sudo apt install --reinstall python-pip

If pip is broken, use:

python -m pip install --force-reinstall pip

Hope it helps!

import main from pip._internal

from pip._internal import main

Edit the pip code from

sudo nano /usr/bin/pip3

As @cryptoboy said – check what pip/python version you have installed

 demon@UbuntuHP:~$ pip -V
 demon@UbuntuHP:~$ pip2 -V
 demon@UbuntuHP:~$ pip3 -V

and then check for no-needed libraries in your .local/lib/ folder.

I did backup of settings when I was migrating to newer Kubuntu and in had .local/lib/python2.7/ folder in my home directory. Installed python 3.6. I just removed the old folder and now everything works great!

On Debian you will need to update apt first….

sudo apt-get update -qq
sudo apt-get install python-pip -qq
sudo pip install pip --upgrade --quiet
sudo pip2 install virtualenv --quiet

If you skip ‘sudo apt-get update -qq’ your pip will become corrupt and display the ‘cannot find main’ error.

This error may be a permission one. So, test executing the command with -H flag:

sudo -H pip3 install numpy

Use the following command before the execution of any pip command

hash -d pip

It will work