外貌溢价学术分组图（学术图表）

def solve():
    import pandas as pd
    import matplotlib.pyplot as plt
    import numpy as np
    
    url = 'https://liangdaima.com/static/data/wooldridge/beauty.csv'
    df = pd.read_csv(url)
    
    plt.rcParams['font.size'] = 12
    groups = df.groupby('belavg')['wage'].agg(['mean', 'sem', 'count'])
    plt.figure(figsize=(8,6))
    plt.bar(['低于平均', '高于平均'], groups['mean'], yerr=groups['sem']*1.96, color=['white', 'white'], edgecolor='black', capsize=5)
    plt.title('外貌与工资', fontsize=14)
    plt.ylabel('平均工资', fontsize=12)
    plt.grid(axis='y', alpha=0.3)
    plt.tight_layout()
    plt.show()
    return "可视化代码执行完成"