String
An immutable sequence of Unicode characters for any text.
- Quotes: single, double, or triple.
- Operations return new strings (immutability).
- Slicing, .split(), .join(), f-strings are the common toolkit.
When to use: Categorical labels, paths, model names, prompts, log messages.
Example: name = "Iris-setosa"; name.lower().split("-") → ["iris", "setosa"]. Original unchanged.