I installed pandas and matplotlib using pip3 install. I then ran this script:

import pandas as pd
import matplotlib.pyplot as plt
data = pd.ExcelFile("Obes-phys-acti-diet-eng-2014-tab.xls")
print (data.sheet_names)

and received this error:

dhcp-169-233-172-97:Obesity juliushamilton$ python3 ob.py
Traceback (most recent call last):
  File "ob.py", line 4, in <module>
    data = pd.ExcelFile("Obes-phys-acti-diet-eng-2014-tab.xls")
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/pandas/io/excel.py", line 169, in __init__
    import xlrd  # throw an ImportError if we need to
ImportError: No module named 'xlrd'

Why is the necessary xlrd missing?

Install the new module:

pip install xlrd

“It’s an optional dependency pandas.pydata.org/pandas-docs/… You can install it separately.” — (bernie, in a now-deleted commented.)