Reference library

Dictionaries & sets

Key–value maps, uniqueness, counting, grouping, and fast lookups.

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Dictionaries & sets easy

How to Group Data by Category in Python with a Split Data Helper

This code groups a list of (category, item) pairs into a dictionary where each key is a category and each value is a list of items belonging to that category.

dictionary grouping iterable
Python 
def split_data(categories):
    """
    Group data items into buckets based on a key function.
    Returns a dict where keys are bucket names and values are lists of items.
    """
    buckets = {}
    for category, item in categories:
        if category not in buckets:
            buckets[category] = []
        buck…
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