文件的位置和用法：apt-get install python- <pkg> 与pip3安装 <pkg>

Question

I found that sudo apt-get install python-<pkg> and sudo pip3 install <pkg> install files in different places.

Is there any way of rendering installation via any of the two options transparent to the user?

In my particular case, it was not, see below. The binary installed by apt-get is removed by pip3 , so its usage is different.

Byproduct questions are:

In the sequence: 1) apt-get install, 2) pip --upgrade, the second step upgrades version and changes files location. But apt-get still thinks it has its original version, at the original location. How can this be fixed?

I meant to install virtualenv . I have just done the following:

1. Install python-virtualenv

    $ sudo apt-get install python-virtualenv Reading package lists... Done ... Setting up virtualenv (15.0.1+ds-3ubuntu1) ... 

2. Check that pip3 reads virtualenv

    $ sudo pip3 install virtualenv The directory '/home/santiago/.cache/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag. The directory '/home/santiago/.cache/pip' or its parent directory is not owned by the current user and caching wheels has been disabled. check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag. Requirement already satisfied: virtualenv in /usr/lib/python3/dist-packages 

3. Find which files were installed. These are in /usr/lib/python3/dist-packages , and pip3 understands this.

    $ ll /usr/lib/python3/dist-packages/virtualenv* -rw-r--r-- 1 root root 100655 Nov 30 08:29 /usr/lib/python3/dist-packages/virtualenv.py /usr/lib/python3/dist-packages/virtualenv-15.0.1.egg-info: total 36 drwxr-xr-x 2 root root 4096 Apr 22 20:48 ./ drwxr-xr-x 146 root root 12288 Apr 22 20:48 ../ -rw-r--r-- 1 root root 1 Nov 30 08:29 dependency_links.txt -rw-r--r-- 1 root root 48 Nov 30 08:29 entry_points.txt -rw-r--r-- 1 root root 1 Nov 30 08:29 not-zip-safe -rw-r--r-- 1 root root 3409 Nov 30 08:29 PKG-INFO -rw-r--r-- 1 root root 11 Nov 30 08:29 top_level.txt 

4. Find the version

    $ virtualenv --version 15.0.1 

5. Use virtualenv

    $ virtualenv my_project Running virtualenv with interpreter /usr/bin/python2 New python executable in /home/santiago/my_project/bin/python2 Also creating executable in /home/santiago/my_project/bin/python Installing setuptools, pkg_resources, pip, wheel...done. 

So this was working well. Now what I did is:

6. Upgrade to the latest version. This had to be done with pip , since apt-get installed its latest available version.

    $ sudo pip3 install --upgrade virtualenv [sudo] password for santiago: The directory '/home/santiago/.cache/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag. The directory '/home/santiago/.cache/pip' or its parent directory is not owned by the current user and caching wheels has been disabled. check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag. Collecting virtualenv Downloading virtualenv-15.1.0-py2.py3-none-any.whl (1.8MB) 100% |████████████████████████████████| 1.8MB 781kB/s Installing collected packages: virtualenv Found existing installation: virtualenv 15.0.1 Uninstalling virtualenv-15.0.1: Successfully uninstalled virtualenv-15.0.1 Successfully installed virtualenv-15.1.0 

7. Try using virtualenv

    $ virtualenv -p python3 my_project bash: /usr/bin/virtualenv: No such file or directory 

8. Find which files were installed. The files installed by apt-get are gone.

    $ ll /usr/lib/python3/dist-packages/virtualenv* ls: cannot access '/usr/lib/python3/dist-packages/virtualenv*': No such file or directory $ ll /usr/bin/virtualenv ll /usr/bin/virtualenv 

9. Try recovering what apt-get gave.

    $ sudo apt-get install python-virtualenv Reading package lists... Done Building dependency tree Reading state information... Done python-virtualenv is already the newest version (15.0.1+ds-3ubuntu1). The following packages were automatically installed and are no longer required: linux-headers-4.4.0-64 linux-headers-4.4.0-64-generic linux-image-4.4.0-64-generic linux-image-extra-4.4.0-64-generic Use 'sudo apt autoremove' to remove them. 0 upgraded, 0 newly installed, 0 to remove and 174 not upgraded. 

Answer 1

Generally it's not a good idea to upgrade package installed with the system package manager ( apt in this case) with pip as they will no longer be managed by the system.

pip will install into /usr/local . The reason your command was not found in your shell is due to command hashing . You can run hash -r and you'll be able to use virtualenv ... again (from /usr/local/bin/virtualenv )

The reason apt believes that virtualenv is still installed is because you have not uninstalled it with apt . An upgrade via pip does not update the dpkg metadata. You can verify this with grep:

# Note: I'm using xenial, if you're on something ealier the package will
# just be called `python-virtualenv` or `python3-virtualenv`
$ grep -C1 '^Package: virtualenv$' /var/lib/dpkg/status

Package: virtualenv
Status: install ok installed
$ grep -C1 '^Package: python3-virtualenv$' /var/lib/dpkg/status

Package: python3-virtualenv
Status: install ok installed