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Functions & basics

Reusable building blocks — parameters, returns, scope, and clear function design.

3 matches

How to Create an Iterator Class with Dunder Methods in Python

A minimal Counter class implementing __iter__ and __next__ to act as a self-iterating iterator, yielding numbers from start to end-1.

iterators dunder-methods class

Python

class Counter:
    def __init__(self, start=0, end=5):
        self.current = start
        self.end = end

    def __iter__(self):
        return self

    def __next__(self):
        if self.current >= self.end:
            raise StopIteration
        value = self.current
        self.current += 1
        return val…

13 0 Open

Functions & basics easy

How to Define a Function with Default Parameter Values in Python

This code demonstrates defining a Python function with default parameter values, showing how to call it with zero, one, or two arguments.

functions default-parameters arguments

Python

def greet(name: str = "World", punctuation: str = "!") -> str:
    """Return a greeting message using default parameter values."""
    message = f"Hello, {name}{punctuation}"
    return message


if __name__ == "__main__":
    # Call with no arguments – uses both defaults
    print(greet())

    # Call with one argume…

13 0 Open

Functions & basics easy

How to Pipe Data Through a List of Transform Functions in Python

Applies a sequence of functions to an initial value using functools.reduce, creating a reusable pipe utility.

functions functional reduce

Python

from functools import reduce

def pipe(data, *transforms):
    return reduce(lambda value, func: func(value), transforms, data)

def double(x):
    return x * 2

def add_one(x):
    return x + 1

def to_string(x):
    return f"Result: {x}"

if __name__ == "__main__":
    initial = 5
    result = pipe(initial, double, …

13 0 Open

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