How can I change the 0 and 1 values in this particular legend to 'No' and 'Yes' respectively?

```py
import matplotlib.pyplot as plt
import numpy as np

plt.contourf(x1, x2, regr.predict(np.array([x1.ravel(), x2.ravel()]).T).reshape(x1.shape), alpha=0.75, cmap = ListedColormap(('red','green')))
for i, j in enumerate(np.unique(y_set)):
    plt.scatter(x_set[y_set == j, 0], x_set[y_set == j,1], c = ListedColormap(('black','white'))(i),label=j)
plt.legend()

```

[Image](https://i.stack.imgur.com/P1ZEB.png)