Cannot switch Python with pyenv

问题

I would like to use pyenv to switch python2 and python3.

I successfully downloaded python2 and python3 and pyenv with following codes.

brew install pyenv

brew install pyenv-virtualenv

pyenv install 2.7.10

pyenv install 3.5.0

However, I cannot switch from python2 to python3..

Soma-Suzuki:~ Soma$ python --version
Python 2.7.10
Soma-Suzuki:~ Soma$ pyenv global
2.7.10
Soma-Suzuki:~ Soma$ pyenv versions
  system
* 2.7.10 (set by /Users/Soma/.pyenv/version)
  3.5.0
Soma-Suzuki:~ Soma$ pyenv global 3.5.0
Soma-Suzuki:~ Soma$ pyenv global
3.5.0
Soma-Suzuki:~ Soma$ pyenv versions
  system
  2.7.10
* 3.5.0 (set by /Users/Soma/.pyenv/version)
Soma-Suzuki:~ Soma$ python --version
Python 2.7.10
Soma-Suzuki:~ Soma$

I do not understand why this happens.

For your information. My python is in this directory.

Soma-Suzuki:~ Soma$ which python
/usr/bin/python

Thank you in advance.

回答1:

try this: eval "$(pyenv init -)"

example:

$ python -V
Python 2.7.9
mac:~ $ eval "$(pyenv init -)"
mac:~ $ python -V
Python 3.5.0

more info: https://github.com/yyuu/pyenv

回答2:

You forgot to add this eval "$(pyenv init -)" to the 1st line in .bash_profile file(if you're using a Mac) or .bashrc file.

回答3:

This answer is only for people that are using Fish shell and find this thread. Pyenv uses shims, ref, so in order to make pyenv work with your fish shell you have to edit your ~/.config/fish/config.fish file an append the pyen shim directory at the beginning of your $PATH variable. Here is what my config.fish looks like.

### PATH ###
set default_path /usr/local/bin /usr/bin /usr/sbin /bin /sbin
set macports /opt/local/bin
set androiddev ~/Android\ Development/platform-tools/
set rbenv ~/.rbenv/shims/
set pyenv ~/.pyenv/shims/
set anaconda /Users/m4punk/anaconda/bin/
set pg_config /Applications/Postgres.app/Contents/Versions/9.5/bin/


### Virtual Enviroment Wrapper ###

set -g VIRTUALFISH_HOME ~/Documents/Coding/python/virtualenvs
set -g VIRTUALFISH_DEFAULT_PYTHON /usr/local/bin/python3
eval (python -m virtualfish)

### NVM Settings ###
set -g NVM_DIR ~/.nvm

set -gx PATH $pyenv $default_path $macports $androiddev $rbenv $pg_config

setenv EDITOR sublime

The relevant lines here are

set pyenv ~/.pyenv/shims/

and

set -gx PATH $pyenv $default_path $macports $androiddev $rbenv $pg_config

The first creates a variable for the pyenv shim path, the second adds it to the front of your path variable. Just save&close, restarted your terminal session and you should be all set.

回答4:

I ran into the same problem and ended up making some changes to the way pyenv init goes about setting up the shell but in the end it works the same. The only real difference from the guide on the pyenv github page is that I had to add the $(pyenv root)/bin directory to my path too.

The reason I did this was to avoid long shell startup times from running eval "$(pyenv init -)" and all the other .bash_profile work that goes into my local shell environment. Just to be clear; Pyenv itself doesn't create a bad shell experience, in my humble opinion, but when you work with several languages that all have their own version management systems and tools that like to be initialized from the .profile with pyenv, etc., the shell initialization process can get slow.

Here's the steps I took to set myself up, at a high view:

Run the dry-run version of the pyenv init command so you can see what it would have done for you.
Put the PATH and shell environment vars into your .bash_profile (or whatever file your distro uses).
Put the function pyenv init printed into your .bashrc and source your .bashrc from your .bash_profile

This is one way to get it done but it's better to use this as "pseudo-code". You should exchange .bash_profile for whatever file your distro prefers.

$ pyenv init - # use the output for reference, it doesn't actually do anything
$ cat <<EOBP > ~/.bash_profile
export PYENV_SHELL=bash
PATH=$(pyenv root)/shims:$(pyenv root)/bin:$PATH
[ -f  /usr/local/Cellar/pyenv/1.2.9/completions/pyenv.bash ] && . /usr/local/Cellar/pyenv/1.2.9/completions/pyenv.bash
[ -f ~/.bashrc ] && . ~/.bashrc
EOBP

The next bit updates your shell with a new bit of logic that we copied from the pyenv init dry run from step 1, above.

$ cat <<EORC > ~/.bashrc
# from $(pyenv init -)
pyenv() {
    local command
    command="${1:-}"
    if [ "$#" -gt 0 ]; then
        shift
    fi

    case "$command" in
    rehash|shell)
        eval "$(pyenv "sh-$command" "$@")";;
    *)
        command pyenv "$command" "$@";;
    esac
}
EORC

来源：https://stackoverflow.com/questions/33321312/cannot-switch-python-with-pyenv

标签

python

pyenv