Creating a virtualenv with python 2 - virtualenv

Question

In ubuntu 16.04 I have in bashrc:
alias python=python3.6
In other words, the command python starts python 3.6.
Now I want a virtualenv with python 2.7.
I have installed virtualenv:
virtualenv -p python2 pgadmin4
Then activated it.
Now check:
$ which python
/home/michael/PycharmProjects/venv/pgadmin4/bin/python
Doublecheck:
(pgadmin4) michael#michael-desktop:~/PycharmProjects/venv/pgadmin4/bin$ ls -la
total 3516
drwxrwxr-x 2 michael michael 4096 окт 12 13:05 .
drwxrwxr-x 7 michael michael 4096 окт 12 13:05 ..
-rw-rw-r-- 1 michael michael 2102 окт 12 13:05 activate
-rw-rw-r-- 1 michael michael 1044 окт 12 13:05 activate.csh
-rw-rw-r-- 1 michael michael 2242 окт 12 13:05 activate.fish
-rw-rw-r-- 1 michael michael 1137 окт 12 13:05 activate_this.py
-rwxrwxr-x 1 michael michael 272 окт 12 13:05 easy_install
-rwxrwxr-x 1 michael michael 272 окт 12 13:05 easy_install-2.7
-rwxrwxr-x 1 michael michael 244 окт 12 13:05 pip
-rwxrwxr-x 1 michael michael 244 окт 12 13:05 pip2
-rwxrwxr-x 1 michael michael 244 окт 12 13:05 pip2.7
lrwxrwxrwx 1 michael michael 7 окт 12 13:05 python -> python2
-rwxrwxr-x 1 michael michael 3546104 окт 12 13:05 python2
lrwxrwxrwx 1 michael michael 7 окт 12 13:05 python2.7 -> python2
-rwxrwxr-x 1 michael michael 2361 окт 12 13:05 python-config
-rwxrwxr-x 1 michael michael 251 окт 12 13:05 wheel
Well, just writing python must run python2.
But:
$ python
Python 3.6.2 (default, Jul 20 2017, 08:43:29)
Could you give me a kick here?

Answer 1

When you activate a virtualenv, under the hood, the PATH environment variable is rewritten to give more priority to the bin directory of your virtualenv.
The which python command tells you the path you expect because it ignores any alias eventually configured. It looks at the PATH environment variable and tries to resolve the current python path.
Bash, instead, takes into account all the alias configured and when you types python, bash resolves the command to python3.6 which is not in you virtualenv bin directory and goes to the system one.
The only possible solutions are:
remove the alias
add a symlink python3.6 -> python inside the bin folder of your virtualenv