Reference library

Dictionaries & sets

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

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Dictionaries & sets easy

How to Normalize Data in Python with Dictionaries and Sets

Normalize a list of dicts by keeping selected keys, stripping/lowercasing strings, and extracting unique sorted values using set comprehension.

dictionaries sets data-cleaning
Python 
def normalize_data(data, keys):
    """
    Normalize a list of dictionaries by keeping only specified keys
    and converting values to proper types.
    """
    normalized = []
    for item in data:
        clean_item = {}
        for key in keys:
            value = item.get(key)
            if isinstance(value, st…
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