绘制散点图

def solve():
    import matplotlib
    matplotlib.use('Agg')
    import matplotlib.pyplot as plt
    from sklearn.datasets import load_iris
    import numpy as np
    iris = load_iris()
    X = iris.data
    y = iris.target
    colors = ['red', 'green', 'blue']
    for i in range(3):
        plt.scatter(X[y==i, 0], X[y==i, 1], c=colors[i], label=iris.target_names[i])
    plt.xlabel('Sepal Length')
    plt.ylabel('Sepal Width')
    plt.title('Iris Scatter Plot')
    plt.legend()
    plt.tight_layout()
    plt.show()
    print(len(X))