ตั้งค่า Virtualenv และติดตั้ง Flask

Each project wants its own package versions. A virtual environment keeps Flask and friends separate from your system Python.

Python ships venv, a built-in tool that creates a private folder holding a fresh, isolated copy of pip and packages.

Run the venv module and pick a folder name like .venv. This builds your isolated environment in seconds. ✨

Activating points your shell at the env. On macOS or Linux you source the activate script inside the env folder.

On Windows the activation script lives under Scripts. Run it and your prompt shows the env name, confirming it is on.

When active, your prompt is prefixed with the env name. Now pip installs land only inside this project, not globally.

With the env active, install Flask using pip. It pulls Flask plus its dependencies like Werkzeug and Jinja2.

Check that Flask is installed and see its version. A clean version number means you are ready to write code.

pip freeze lists exact versions. Saving them lets teammates rebuild the same environment later with one command.

Anyone can recreate your setup from requirements.txt, so your project runs the same on every machine.

Type deactivate to leave the environment and return to your normal shell. Reactivate any time you work on the project.

Quick check on isolating your project.

You created a venv, activated it, installed Flask with pip, and froze your deps. Your isolated workspace is ready to build. 🎉