类别分布可视化

def solve():
    import pandas as pd
    import matplotlib.pyplot as plt
    df = pd.read_csv("https://data.zuihe.com/iris.csv")
    vc = df["species"].value_counts().sort_index()
    plt.bar(vc.index, vc.values, color=["#e41a1c","#377eb8","#4daf4a"])
    plt.xlabel("Species"); plt.ylabel("Count"); plt.title("Iris Class Distribution")
    plt.show()
    print(",".join(f"{k}:{v}" for k, v in vc.items()))