ModuleNotFoundError: No module named 'numpy' after using 'pip install numpy'
Welcome to SO!

It is likely that there are 2 python versions(Python2.X and Python3.X) are installed in your system.
pip is likely pointing to your Python2.X and so if you want to used libraries installed in this version ===> use python to run
pip3 is pointing to your Python3.X, so use Python3 in your terminal to use this.

Note:

To know installed libraries in your python2 use pip freeze or pip3 freeze for Python3
In case, if you are getting error for Python3 as not then this is like to be system path issues.

If you are still having trouble, you learn more about Anaconda-Python which has a curated list of steps and guidelines that are easy for beginners too. Hope this helps!
I tried installing numpy using the command 'pip install numpy' and ran 'import numpy' but I received the error ModuleNotFoundError: No module named 'numpy' when I tried to re-run the code. After reading similar questions on SO, I ran pip3 install numpy, but since i already installed it, I received the message Requirement already satisfied.
NOTE: I have read other similar questions on SO, but none of them solve my problem.

Possible solution for future readers:
Like @Sampath mentioned in his answer, I had two versions of python installed. To solve the issue, I manually deleted all the installation files of the older version.