Matplotlib Issues in venv

Question

I have encountered an issue I've never really had before. I am pretty familiar with matplotlib and making figure objects, axes and all that. However, when I try to run this EXTREMELY simple code in matplotlib...

import numpy as np
import matplotlib.pyplot as plt

x = np.arange(0,21)
y = x
plt.plot(x,y)
plt.show()

I get the following error...

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
Input In [7], in <module>
      1 plt.plot(x,y)
----> 2 plt.show()

AttributeError: 'AxesSubplot' object has no attribute 'show'

I cannot understand why I am getting this attribute error. I do not think this is a code issue, as this is the simplest possible matplotlib code that we could write (this should return a line of slope 1 in a range of 1 to 20, basically the 'hello world' of matplotlib). Does anyone have insight into why I'm getting this error?

I suspect that this is a package issue. This is my first time using matplotlib in a python venv, as opposed to a conda virtual environment. When I pip install matplotlib, I feel like I may be missing a package that supports the .show() method. I never had an issue using matplotlib on the conda environment because I installed it through the anaconda navigator. I trust that the pip install would take care of any package dependencies, but I'm not sure. If anyone has insight it would be much appreciated.