Reference library

Comprehensions & generators

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

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Comprehensions & generators easy

Python Generator to Filter Duplicates with a Seen Set

A lazily-evaluated generator function that yields only the first occurrence of each item, using a set to track seen values.

generator dedupe set
Python 
def unique_generator(items):
    seen = set()
    for item in items:
        if item not in seen:
            seen.add(item)
            yield item

if __name__ == "__main__":
    data = [1, 2, 2, 3, 3, 3, 4, 5, 5]
    result = list(unique_generator(data))
    print(result)
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Comprehensions & generators — Python code examples

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