Beginner LevelPython
Why are f-strings (formatted string literals) superior to % formatting and str.format()?
❓ Interview Prompt: Explain string formatting evolution: % formatting (legacy C-style), `.format()` method, f-strings (`f'{var}'`), performance, and inline expressions.
Introduced in Python 3.6 (PEP 498), f-strings ('f'Hello {name}'') provide the fastest and most readable way to format strings:
Advantages:
•
Performance: Evaluated at runtime into fast bytecode, significantly faster than '%' or '.format()'.
•
Inline Expressions: Supports arbitrary Python expressions, specifiers ('f'{val:.2f}''), and debugging syntax ('f'{var=}'' in Python 3.8+).
Code Implementation Example
python
name = 'Alice'
price = 49.9982
# Inline expression, formatting specifier (.2f), and debug format (=)
print(f'User: {name.upper()}')
print(f'Total: ${price:.2f}') # Total: $50.00
print(f'{name=}') # name='Alice' (Python 3.8+ Debug syntax!)💡Formatting strings using f-strings with precision specifiers and debug syntax.
🎯 Interview Key Takeaway
Use f-strings for string interpolation because they are faster, cleaner, and support inline expressions.
#f-strings#String Formatting#PEP 498#Beginner
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