String methods

Strings are immutable: every method returns a new string. split and join are the pair you reach for most — one turns text into a list, the other turns a list back into text.

Tests and cleanup: startswith, endswith, in, replace, removeprefix and the case helpers. Compare case-insensitively by lowering both sides.

f-strings format values inline, including alignment and rounding, which keeps printed output readable.