This problem has been tormenting for a whole day and finally solved!
I downloaded the matplotlib package from Anaconda and wrote the code using PyCharm, but no matter what, an error occurred and the message "from" appeared Import multiarray ImportError: The error of importing DLL failed. After searching through a lot of information, it was finally resolved.
Solution:
The matplotlib package downloaded in Anaconda cannot be imported and needs to be downloaded in PyCharm. The specific steps are as follows:
After installation.
Be sure to restart!!!
Be sure to restart!!!
Be sure to restart!!!
The lesson of blood and tears.