L1·Foundations
🔤Strings & f-strings
Immutable text sequences and rich formatting.
strformatf-stringslicing
§ 1Immutable sequences
Strings are sequences of Unicode code points. You can slice them but not mutate in place.
§ 2f-strings
f"..." evaluates expressions inside {}. Supports formatting mini-language: {value:.2f}, {n:>10}, {n:,}.
§ 3Common methods
.upper() .lower() .strip() .split() .replace() .startswith() .endswith() .join().
Example
1name = "ada"2age = 363print(f"{name.title()} is {age} years old")4print(f"pi ≈ {3.14159:.2f}")5print("-".join(["a", "b", "c"]))Try it live · Python runs in your browser
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What is 'python'[1:4]?