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Strings & text

Format, split, join, parse, and clean text — everyday Python string patterns.

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Strings & text easy

How to Group Data by Category in Python

Group a list of (category, value) tuples into a dictionary of lists using the setdefault method.

grouping dictionaries setdefault
Python 
def group_by_category(data):
    """Group list of (category, value) tuples into dictionaries of lists."""
    groups = {}
    for category, value in data:
        groups.setdefault(category, []).append(value)
    return groups

if __name__ == "__main__":
    items = [
        ("fruit", "apple"),
        ("veg", "carro…
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This page collects strings & text snippets — short, copy-ready Python you can paste into our free online IDE and run without installing anything. Each sample includes a plain-English explanation and the full source code.

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Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.

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