如何将 pip 命令覆盖为 Python3.x 而不是 Python2.7？

Question

I am using OSX and I have pip installed for both Python3.5 and Python2.7. I know I can run the command pip2 to use Python2 and when I use the command pip3 Python3.x will be used. The problem is that the default of pip is set to Python2.7 and I want it to be Python3.x.

How can I change that?

edit: No, I am not running a virtual environment yet. If it was a virtual environment I could just run Python3.x and forget all about Python2.7, unfortunately since OSX requires Python2.7 for it's use I can't do that. Hence why I'm asking this.

Thanks for the answer. I however don't want to change what running python does. Instead I would like to change the path that running pip takes. At the moment pip -V shows me pip 8.1.2 from /Library/Python/2.7/site-packages (python 2.7) , but I am looking for pip 8.1.2 from /Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages (python 3.5) I am sure there has to be a way to do this. Any ideas?

Answer 1

Run this:

pip3 install --upgrade --force pip

or even more explicit:

python3 -m pip install --upgrade --force pip

This will install pip for Python 3 and make Python 3 version of pip default.

Validate with:

pip -V

Answer 2

I always just run it via Python itself, this way:

python3 -m pip install some_module

or

python2 -m pip install some_module

The -m calls the __main__.py module of a specified package. Pip supports this.

Answer 3

Can't you alias pip='pip3' in your ~/.bash_profile ?

In Terminal, run nano ~/.bash_profile , then add a line to the end that reads alias pip='pip3' . This is safe; it won't affect system processes, only your terminal.

Answer 4

For your projects, you should be using a virtualenv .

You can choose which python will be that of the virtualenv at creation time, by specifying it on the command line:

virtualenv -p python3 env
# then
. env/bin/activate
python              # ← will run python3

That python interpreter will be the one used when you run python or pip while the virtualenv is active.

Under the hood, activating the virtualenv will:

• modify your PATH environment setting so binaries in env/bin override those from your system.
• modify your PYTHONHOME environment setting so python modules are loaded from env/lib .

So python , pip and any other package you install with pip will be run from the virtualenv, with the python version you chose and the package versions you installed in the virtualenv.

Other than this, running python without using virtualenv will just run the default python of the system, which you cannot usually change as it would break a lot of system scripts.

Answer 5

Although PEP 394 does not specifically mention pip , it does discuss a number of other Python-related commands (including python itself). The short version is that, for reasons of backwards compatibility, the unversioned commands should refer to Python 2.x for the immediate future on most reasonable systems.

Generally, these aliases are implemented as symbolic links, and you can just flip the symlink to point at the version you want (eg with ln -f -s $(which pip3) $(which pip) as root). But it may not be a good idea if you have any software that expects to interact with Python 2 (which may be more than you think since a lot of software interacts with Python).

The saner option is to set up a Virtualenv with Python 3. Then, within the Virtualenv , all Python-related commands will refer to 3.x instead of 2.x. This will not break the system, unlike the previous paragraph which could well break things.

Answer 6

Since you have specified in the comments you want syntax like pip install [package] to work, here is a solution:

1. Install setuptools for Python3 : apt-get install python3-setuptools

2. Now pip for Python3 could be installed by: python3 -m easy_install pip

3. Now you can use pip with the specific version of Python to install package for Python 3 by: pip-3.2 install [package]

Answer 7

It works for me:

As super-user

Uninstall pip

sudo pip uninstall pip

Install pip

sudo python3 -m pip install --upgrade --force pip

Check install path

sudo pip -V

As local-user

Uninstall pip

pip uninstall pip

Install pip

python3 -m pip install --upgrade --force pip

Check install path

pip -V