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Data pipelines & processing

ETL-style flows, batch transforms, validation, and moving data between formats.

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Data pipelines & processing medium

How to Topologically Sort a DAG in Python

Compute a valid execution order for tasks with dependencies using Kahn's algorithm in Python.

dag topological-sort graph
Python 
from collections import defaultdict, deque


def topological_order(dependencies):
    graph = defaultdict(list)
    in_degree = defaultdict(int)
    tasks = set(dependencies.keys())

    for task, depends_on in dependencies.items():
        for d in depends_on:
            graph[d].append(task)
            in_degree[t…
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