Ubuntu 14.04 - Python 3.4 - pyenv：找不到命令

Question

I am trying to create a virtual environment for Python 3.4 on a fresh install of Ubuntu Server 14.04. I following the instructions for the venv module at:

https://docs.python.org/3/library/venv.html#module-venv

I don't have a lot of Python 3.4 or Ubuntu experience.

When I type the command:

pyvenv testDir

I get back:

pyvenv: command not found

What is causing this?

Answer 1

Ubuntu 14.04 uses Python 2 by default, and the pyenv command does not exist in Python 2 out of the box.

You can, however, use virtualenv for the same purpose. You just need to install it!

You should:

• Install Python 3 and virtualenv apt-get install -y python3 python-virtualenv
• Create a Python 3 virtualenv: virtualenv -p $(which python3) testDir
• Activate the virtual environment with source testDir/bin/activate

Answer 2

It's also possible to create virtualenv by python itself. python3 -m venv myenv

see documentation https://docs.python.org/3/library/venv.html

Answer 3

It's in the package python3.4-venv (Linux Mint) or python3-venv (Ubuntu - I guess).

The advantages of venv over virtualenv are that (1) it's in vanilla Python3, (2) interpreter does retain tab-completion.

Answer 4

Edit the .bashrc file present in your home directory by adding below code and save the file:

# Load pyenv automatically by adding
# the following to ~/.bashrc:
export PATH="/home/'Enter systemname here'/.pyenv/bin:$PATH"
eval "$(pyenv init -)"
eval "$(pyenv virtualenv-init -)"

After this you can now run the following command:

    exec $SHELL

Now pyenv works properly