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Comprehensions & generators

List/dict/set comprehensions, generator expressions, and lazy iteration.

3 matches

How to Delegate Iteration to a Subgenerator with yield from in Python

Use yield from to delegate iteration from one generator to a subgenerator, flattening nested generator output into a single sequence.

generators yield-from delegation

Python

def subgenerator():
    yield "first"
    yield "second"
    yield "third"


def delegate():
    yield "before delegation"
    yield from subgenerator()
    yield "after delegation"


if __name__ == "__main__":
    for item in delegate():
        print(item)

13 0 Open

Comprehensions & generators easy

How to Parse Data with Generators and Comprehensions in Python

This code demonstrates using a generator expression to filter active users and a dictionary comprehension to aggregate scores by name.

generator expressions dictionary comprehensions filtering

Python

def parse_data_helper(raw_records):
    """Extract active users' names and scores from raw records."""
    parsed = (
        (record["name"], record["score"])
        for record in raw_records
        if record["active"] and record["score"] >= 0
    )
    return list(parsed)


def aggregate_scores(parsed_data):
    "…

15 0 Open

Comprehensions & generators easy

Sum of Squares with a Generator Expression in Python

This code computes the sum of squares of integers from 1 to n using a generator expression, demonstrating a memory-efficient and concise way to aggregate a sequence.

generator sum squares

Python

def sum_of_squares(n):
    return sum(x * x for x in range(1, n + 1))

if __name__ == "__main__":
    print(f"Sum of squares from 1 to 5: {sum_of_squares(5)}")
    print(f"Sum of squares from 1 to 10: {sum_of_squares(10)}")

14 0 Open

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