性别平均工资柱状图（分组比较）

def solve():
    import pandas as pd
    import matplotlib.pyplot as plt
    import numpy as np
    
    url = 'https://liangdaima.com/static/data/wooldridge/wage1.csv'
    df = pd.read_csv(url)
    
    gender_means = df.groupby('female')['wage'].mean()
    plt.figure(figsize=(8,6))
    bars = plt.bar(['男性', '女性'], gender_means.values, color=['steelblue', 'coral'])
    for bar, val in zip(bars, gender_means.values):
        plt.text(bar.get_x() + bar.get_width()/2, bar.get_height() + 0.1, f'{val:.2f}', ha='center')
    plt.title('不同性别平均工资', 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"