How Do You Troubleshoot “ImportError: No module named ‘pandas'”?

Problem scenario
From a Python command line, you get this message:

Traceback (most recent call last):
File "", line 1, in
ImportError: No module named 'pandas'

What should you do?

Solution
Prerequisite
You need pip to be installed. If you need assistance, see this posting.

Procedures
Run one of these commands:

pip install pandas

pip3 install pandas