`python3` - an interpreted, interactive, object-oriented programming language

python3 [-c command | -m module | script] [arguments]

Options you will use

-c command: Run the Python code in command.
-m module: Run a library module as a script: -m venv DIR, -m pip, -m pytest, -m json.tool FILE, -m py_compile FILE.
-V, --version: Print the version and exit.
-u: Unbuffered stdout and stderr - log lines show up at once under systemd and Docker (or PYTHONUNBUFFERED=1).
-B: Do not write .pyc files.
-i: Inspect interactively after running the script.
-I: Isolate: ignore PYTHON* variables and the user site directory.
-W ARG: Warning control, e.g. -W error.
-X OPT: Implementation-specific options, e.g. -X importtime.
-u: Unbuffered stdout and stderr - log lines show up at once under systemd and Docker (or PYTHONUNBUFFERED=1).
-B: Do not write .pyc files.
-i: Inspect interactively after running the script.
-I: Isolate: ignore PYTHON* variables and the user site directory.
-W ARG: Warning control, e.g. -W error.
-X OPT: Implementation-specific options, e.g. -X importtime.

$ python3 -m venv .venv

Create a virtual environment (needs the python3-venv package on Ubuntu).

$ source .venv/bin/activate

Put the venv first on PATH, so python and pip mean the venv ones.

$ python3 healthcheck.py --timeout 2 http://localhost:8080/actuator/health

Run a script with arguments.

$ python3 -m json.tool pods.json

Pretty-print JSON.

Ubuntu marks the system interpreter as externally managed (PEP 668): pip refuses to install into it. Use a venv per tool, or pipx for applications.

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