I've got two versions of python on my linuxbox:
$python
Python 2.6.6 (r266:84292, Jul 10 2013, 22:48:45)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-3)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>
$ /usr/local/bin/python2.7
Python 2.7.3 (default, Oct 8 2013, 15:53:09)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-3)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>
$ which python
/usr/bin/python
$ ls -al /usr/bin/python
-rwxr-xr-x. 2 root root 4864 Jul 10 22:49 /usr/bin/python
How can I make 2.7 be the default version so when I type python it puts me in 2.7?
Verify current version of python by:
$ python --version
then check python is symbolic link to which file.
$ ll /usr/bin/python
Output Ex:
lrwxrwxrwx 1 root root 9 Jun 16 2014 /usr/bin/python -> python2.7*
Check other available versions of python:
$ ls /usr/bin/python*
Output Ex:
/usr/bin/python /usr/bin/python2.7-config /usr/bin/python3.4 /usr/bin/python3.4m-config /usr/bin/python3.6m /usr/bin/python3m
/usr/bin/python2 /usr/bin/python2-config /usr/bin/python3.4-config /usr/bin/python3.6 /usr/bin/python3.6m-config /usr/bin/python3m-config
/usr/bin/python2.7 /usr/bin/python3 /usr/bin/python3.4m /usr/bin/python3.6-config /usr/bin/python3-config /usr/bin/python-config
If want to change current version of python to 3.6 version edit file ~/.bashrc:
vim ~/.bashrc
add below line in the end of file and save:
alias python=/usr/local/bin/python3.6
To install pip for python 3.6
$ sudo apt-get install python3.6 python3.6-dev
$ sudo curl https://bootstrap.pypa.io/ez_setup.py -o - | sudo python3.6
$ sudo easy_install pip
On Success, check current version of pip:
$ pip3 -V
Output Ex:
pip 1.5.4 from /usr/lib/python3/dist-packages (python 3.6)
Add /usr/local/bin to your PATH environment variable, earlier in the list than /usr/bin.
Generally this is done in your shell's rc file, e.g. for bash, you'd put this in .bashrc:
export PATH="/usr/local/bin:$PATH"
This will cause your shell to look first for a python in /usr/local/bin, before it goes with the one in /usr/bin.
(Of course, this means you also need to have /usr/local/bin/python point to python2.7 - if it doesn't already, you'll need to symlink it.)
Enter the command
which python
//output:
/usr/bin/python
cd /usr/bin
ls -l
Here you can see something like this
lrwxrwxrwx 1 root root 9 Mar 7 17:04 python -> python2.7
your default python2.7 is soft linked to the text 'python'
So remove the softlink python
sudo rm -r python
then retry the above command
ls -l
you can see the softlink is removed
-rwxr-xr-x 1 root root 3670448 Nov 12 20:01 python2.7
Then create a new softlink for python3.6
ln -s /usr/bin/python3.6 python
Then try the command python in terminal
//output:
Python 3.6.7 (default, Oct 22 2018, 11:32:17)
[GCC 8.2.0] on linux
Type help, copyright, credits or license for more information.
I guess you have installed the 2.7 version manually, while 2.6 comes from a package?
The simple answer is: uninstall python package.
The more complex one is: do not install manually in /usr/local. Build a package with 2.7 version and then upgrade.
Package handling depends on what distribution you use.
All OS comes with a default version of python and it resides in /usr/bin. All scripts that come with the OS (e.g. yum) point this version of python residing in /usr/bin. When you want to install a new version of python you do not want to break the existing scripts which may not work with new version of python.
The right way of doing this is to install the python as an alternate version.
e.g.
wget http://www.python.org/ftp/python/2.7.3/Python-2.7.3.tar.bz2
tar xf Python-2.7.3.tar.bz2
cd Python-2.7.3
./configure --prefix=/usr/local/
make && make altinstall
Now by doing this the existing scripts like yum still work with /usr/bin/python. and your default python version would be the one installed in /usr/local/bin. i.e. when you type python you would get 2.7.3
This happens because. $PATH variable has /usr/local/bin before usr/bin.
/usr/lib64/qt-3.3/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin
If python2.7 still does not take effect as the default python version you would need to do
export PATH="/usr/lib64/qt-3.3/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"
Source: Stackoverflow.com