标准差计算器

import statistics

def full_stats(data, population=True):
    """Calculate comprehensive statistics for a dataset."""
    n = len(data)
    total = sum(data)
    mean = total / n
    if population:
        variance = sum((x - mean) ** 2 for x in data) / n
    else:
        variance = sum((x - mean) ** 2 for x in data) / (n - 1)
    std_dev = variance ** 0.5
    sorted_data = sorted(data)
    mid = n // 2
    median = (sorted_data[mid - 1] + sorted_data[mid]) / 2 if n % 2 == 0 else sorted_data[mid]
    # Mode
    from collections import Counter
    freq = Counter(data)
    max_freq = max(freq.values())
    mode = [k for k, v in freq.items() if v == max_freq] if max_freq > 1 else []
    cv = (std_dev / abs(mean)) * 100 if mean != 0 else 0
    return {
        "count": n, "sum": total, "mean": mean,
        "variance": variance, "std_dev": std_dev,
        "min": sorted_data[0], "max": sorted_data[-1],
        "range": sorted_data[-1] - sorted_data[0],
        "median": median, "mode": mode,
        "cv_pct": cv,
    }

data = [4, 8, 15, 16, 23, 42]
result = full_stats(data, population=True)
for k, v in result.items():
    print(f"{k:12}: {v}")