Which answer is correct?

Use `string.Template("Hello, $name!").substitute(name=name)`. It's the safest for user-provided templates.

— safe_template

Use `.format()`: `"Hello, {}!".format(name)`. It's the most flexible and works in all Python 3 versions.

— format_fan

Use `%` formatting: `"Hello, %s!" % name`. Classic C-style, works everywhere.

— c_style

Use f-strings: `f"Hello, {name}!"`. They're faster, more readable, and support expressions. Available in Python 3.6+.

— modern_py