Your first Python program
A temperature converter — a function, a loop, and readable output.
A program that converts a few Celsius temperatures to Fahrenheit and prints them.
Defining a function, returning a value, f-strings, and a simple loop.
Prerequisites
Python installed locally to run it, or just read along — the code is here.
Python is famous for reading almost like plain English. Here is a small, complete program — a temperature converter. Open it in /code to edit, and run it locally to see it work.
def to_fahrenheit(celsius: float) -> float: """Convert a Celsius temperature to Fahrenheit.""" return celsius * 9 / 5 + 32 for c in (0, 37, 100): print(f"{c}°C = {to_fahrenheit(c)}°F")Functions
`def name(args):` defines a reusable unit of work. `return` hands a value back to whoever called it.
def to_fahrenheit(celsius): return celsius * 9 / 5 + 32 print(to_fahrenheit(100)) # 212.0$python main.py0°C = 32.0°F
37°C = 98.6°F
100°C = 212.0°F
Milestone
You wrote and ran a Python program.
A function, a loop, and formatted output — the three things almost every Python script is built from.
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