综合案例-数据可视化3

def solve():
    import pandas as pd
    import matplotlib.pyplot as plt
    df = pd.read_csv(____)
    avg_salary = df.groupby(____)['____'].mean()
    plt.figure(figsize=(____, ____))
    plt.bar(____)
    plt.title(____)
    plt.xlabel(____)
    plt.ylabel(____)
    plt.savefig(____)
    plt.close()
    print(____)