In Kali Linux, why do I only see python2 and python3 binaries (NOT a 'python' binary) in /usr/bin/ and get "python command not found"

Question

I am running latest version of Kali Linux:

uname -a                           
Linux User 5.14.0-kali4-amd64 #1 SMP Debian 5.14.16-1kali1 (2021-11-05) x86_64 GNU/Linux

It already came with Python 3.9.8. But I needed to install Python 2.7. So I first installed it with sudo apt install python2.7.18. But following happened:

python -V        
Command 'python' not found, did you mean:
  command 'python3' from deb python3
  command 'python' from deb python-is-python3

python2 -V  
Python 2.7.18

python3 -V       
Python 3.9.8

Also:

which python
python not found

WHAT I TRIED:

I checked locations such as /usr/opt/ , /usr/bin/ , /usr/share/ etc. I checked /usr/bin and found python2 and python3 binaries:

So I reckoned that python environment variable is not set. I added python=/usr/bin/python2 to /etc/environment and then did source /etc/environment . But that did not help.

Then I checked /usr/share and found that python folder Was there.

---

Then I did some research on the internet and found pyenv , which apparently allows us to install and use multiple Python versions without them conflicting with each other. So I followed all steps in the given guide to isntall Python 2.7.18 and set it as default. But that did not solve the problem either

sudo apt install -y build-essential libssl-dev zlib1g-dev libbz2-dev libreadline-dev libsqlite3-dev wget curl llvm libncurses5-dev libncursesw5-dev xz-utils tk-dev libffi-dev liblzma-dev python3-openssl git

curl https://pyenv.run | bash

echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.zshrc     

echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.zshrc

echo -e 'if command -v pyenv 1>/dev/null 2>&1; then\n  eval "$(pyenv init -)"\nfi' >> ~/.zshrc

exec $SHELL

pyenv 2.2.3

pyenv install 2.7.18

pyenv global 2.7.18

Then I checked:

pyenv versions                                                                                                                                                                              1 ⨯
  system
* 2.7.18 (set by /home/bruno/.pyenv/version)

So far so good. But then:

python           
Command 'python' not found, did you mean:
  command 'python3' from deb python3
  command 'python' from deb python-is-python3

Moreover, to confirm:

Answer 1

Because that distribution wants to be clear about which version of Python you're running, and it's perfectly allowed to do so .

In short, you'll have to use python3 to run Python 3.x, and python2 (if such a symlink gets set up by pyenv , or if you apt install python2.7 (if it's even available on Kali)) to run Python 2.x.

Please remember Python 2.x is EOL, and you shouldn't use it for any new development.

Answer 2

Manually adding path to /home/bruno/.pyenv/versions/2.7.18/bin to $PATH environment variable solved the python command not found for me, because that directory contains python binary.