cbook must import matplotlib only within function

If you want to import `matplotlib` only within a specific function, you can do so by placing the import statement inside that function. Here's an example:

def plot_data(data):
    import matplotlib.pyplot as plt

    # Plot the data using matplotlib
    plt.plot(data)
    plt.show()

# Call the function with some sample data
data = [1, 2, 3, 4]
plot_data(data)

In this example, the `import matplotlib.pyplot as plt` statement is placed inside the `plot_data()` function. That way, `matplotlib` is only imported when the function is called, and not at any other point in the program. This can be useful if you only need to use `matplotlib` in a specific part of your code, and don't want to import it globally.