It sounds like you’re in a bit of a tricky situation with needing Python 2.7 for your legacy app! Don’t worry; there’s a way to install it without messing up your existing setup. Here’s a simple approach:

1. Use APT to install Python 2.7

Since you’re on Ubuntu, you can use apt-get to install Python 2.7 easily. Just open your terminal and run the following command:

sudo apt-get update
sudo apt-get install python2.7

2. Check your Python installation

After it’s done, check if it installed correctly by running:

python2.7 --version

You should see something like Python 2.7.x (where x is the version number).

3. Using pip for Python 2.7

For managing packages with Python 2.7, you’ll want pip. You can install it using:

sudo apt-get install python-pip

Then, you can use pip just like normal:

pip install some-package

4. Consider using a virtual environment

To keep things tidy and avoid potential conflicts, using a virtual environment is a good idea. Install virtualenv:

sudo pip install virtualenv

Then, create a virtual environment for Python 2.7:

virtualenv -p python2.7 myenv

Activate it with:

source myenv/bin/activate

Now any packages you install will only be in this environment!

5. A few extra tips

Make sure to avoid using sudo with pip inside virtual environments to keep things simple. Also, when you’re done with the virtual environment, you can deactivate it by just running:

deactivate

Final thoughts

Installing Python 2.7 shouldn’t break your current setup as long as you keep it organized, especially with virtual environments. Just remember to activate your environment whenever you work on that legacy app. Good luck, and happy coding!