How to Implement MapReduce Word Count in Python Using a Dict

def map_reduce_word_count(text: str) -> dict:
    """Simulate a MapReduce pipeline to count word frequencies."""
    # MAP phase: split into words and emit (word, 1) pairs
    mapped = []
    for word in text.lower().split():
        # Clean word of punctuation
        clean_word = ''.join(char for char in word if char.isalnum())
        if clean_word:
            mapped.append((clean_word, 1))
    
    # SHUFFLE phase: group by key
    shuffled = {}
    for key, value in mapped:
        if key not in shuffled:
            shuffled[key] = []
        shuffled[key].append(value)
    
    # REDUCE phase: sum values per key
    result = {}
    for key, values in shuffled.items():
        result[key] = sum(values)
    
    return result


if __name__ == "__main__":
    sample_text = "the quick brown fox jumps over the lazy dog the fox"
    counts = map_reduce_word_count(sample_text)
    print("Word count results:", counts)
    print("Total unique words:", len(counts))