AttributeError: module 'matplotlib' has no attribute 'pyplot'

This error occurs because the `pyplot` module is not directly imported when importing `matplotlib`.

To resolve this error, you need to explicitly import the `pyplot` module from `matplotlib` by adding the following line of code:

import matplotlib.pyplot as plt

Then, you can use `plt` instead of `matplotlib.pyplot` in your code. For example:

import matplotlib.pyplot as plt

x = [1, 2, 3, 4]
y = [1, 4, 9, 16]

plt.plot(x, y)
plt.show()