In this tutorial I will show you how to convert xls to xlsx. Initially I  install pandas package and write the following code. 
import pandas as pd
df = pd.read_excel('data/file_emp1.xls', header=None)
df.to_excel('data/file_2003.xlsx', index=False, header=False)
After running the program I go this following error.
"ImportError: Missing optional dependency 'xlrd'. Install xlrd greater than = 1.0.0 for Excel support Use pip or conda to install xlrd"

To Resolve this error install xlrd.

pip install xlrd

VIDEO GUIDE: